chore: retrigger CI after lint-and-test runner shutdown (#4205)

Chromium only enables gnome-libsecret or kwallet when it recognizes a
GNOME/KDE desktop name, so niri/sway/Hyprland fall through to BASIC_TEXT
even when org.freedesktop.secrets is available. Set --password-store
before app ready when Secret Service is present, without overriding an
explicit switch or KDE's kwallet default.

README.ja-JP.md

@@ -141,6 +141,7 @@ Catty Agent にサーバーの健全性チェックを依頼すると、適切
 ### 📁 SFTP + 内蔵エディタ
 - **ファイル作業** — ドラッグ＆ドロップでアップロード/ダウンロード
 - **その場で編集** — 内蔵エディタで小さな修正を素早く
+- **リモート圧縮** — ファイルやフォルダーを1つ以上選び、右クリックの **Compress...** から、表示された保存先に名前を指定して `.tar.gz` または `.zip` アーカイブを作成できます。サーバーには選択した形式に対応する `tar`/`gzip` または `zip` が必要です。
 
 ### 🎨 パーソナライズ
 - **カスタムテーマ** — UI の見た目を好みに調整

README.md

@@ -144,6 +144,7 @@ If you regularly work with a fleet of servers, Netcatty is built for speed and f
 ### 📁 SFTP + Built-in Editor
 - **File workflows** — drag & drop uploads/downloads
 - **Edit in place** — built-in editor for quick changes
+- **Create remote archives** — select files or folders, right-click **Compress...**, and create a named `.tar.gz` or `.zip` archive in the displayed destination directory; the server needs `tar`/`gzip` or `zip` for the chosen format.
 
 ### 🎨 Personalization
 - **Custom themes** — tune the app appearance to your taste

README.zh-CN.md

@@ -141,6 +141,7 @@
 ### 📁 SFTP + 内置编辑器
 - **文件工作流** —— 拖拽上传/下载更直观
 - **就地编辑** —— 内置编辑器快速修改文件
+- **远程压缩** —— 单选或多选文件、文件夹，右键选择“压缩…”，在对话框显示的保存目录生成指定名称的 `.tar.gz` 或 `.zip` 压缩包；服务器需安装对应的 `tar`/`gzip` 或 `zip`。
 
 ### 🎨 个性化
 - **自定义主题** —— 按喜好调整应用外观

README.zh-TW.md

@@ -141,6 +141,7 @@
 ### 📁 SFTP + 內建編輯器
 - **檔案工作流** —— 拖放上傳／下載
 - **就地編輯** —— 內建編輯器，快速修改檔案
+- **遠端壓縮** —— 單選或多選檔案、資料夾，按右鍵選擇「壓縮…」，在對話方塊顯示的儲存目錄建立指定名稱的 `.tar.gz` 或 `.zip` 壓縮檔；伺服器需安裝對應的 `tar`/`gzip` 或 `zip`。
 
 ### 🎨 個人化
 - **自訂主題** —— 依你的喜好調整外觀

application/AppHandlers.globalHotkeys.test.ts

@@ -377,7 +377,7 @@ test('move-focus shortcut cannot send input behind a magnified pane', () => {
   assert.equal(moveCalls, 0);
 });
 
-test('Escape restores magnification after transient dialogs are closed', () => {
+test('Escape leaves magnification unchanged and reaches the terminal', () => {
   let restores = 0;
   let prevented = false;
   let stopped = false;
@@ -405,30 +405,29 @@ test('Escape restores magnification after transient dialogs are closed', () => {
     },
   }), event);
 
-  assert.equal(restores, 1);
-  assert.equal(prevented, true);
-  assert.equal(stopped, true);
+  assert.equal(restores, 0);
+  assert.equal(prevented, false);
+  assert.equal(stopped, false);
 });
 
-test('consumed Escape does not restore magnification', () => {
-  let restores = 0;
+test('Escape closes the quick switcher', () => {
+  let open = true;
   handleEscapeKeyDownImpl(() => ({
-    isQuickSwitcherOpen: false,
-    setIsQuickSwitcherOpen: () => {},
-    terminalPaneMagnificationRef: {
-      current: {
-        getState: () => 'focused',
-        focus: () => false,
-        restore: () => {
-          restores += 1;
-          return true;
-        },
-        toggle: () => false,
-      },
-    },
+    isQuickSwitcherOpen: open,
+    setIsQuickSwitcherOpen: (value: boolean) => { open = value; },
+  }), { key: 'Escape', defaultPrevented: false } as KeyboardEvent);
+
+  assert.equal(open, false);
+});
+
+test('consumed Escape leaves the quick switcher open', () => {
+  let open = true;
+  handleEscapeKeyDownImpl(() => ({
+    isQuickSwitcherOpen: open,
+    setIsQuickSwitcherOpen: (value: boolean) => { open = value; },
   }), { key: 'Escape', defaultPrevented: true } as KeyboardEvent);
 
-  assert.equal(restores, 0);
+  assert.equal(open, true);
 });
 
 test('close tab hotkey routes native plugin view tabs through their owner', () => {

application/app/AppHandlers.ts

@@ -365,8 +365,6 @@ export function handleEscapeKeyDownImpl(getCtx: AppContextGetter, e: KeyboardEve
   const {
     isQuickSwitcherOpen,
     setIsQuickSwitcherOpen,
-    sftpPaneMagnificationRef,
-    terminalPaneMagnificationRef,
   } = getCtx();
 {
     if (e.key !== 'Escape' || e.defaultPrevented) return;
@@ -374,13 +372,6 @@ export function handleEscapeKeyDownImpl(getCtx: AppContextGetter, e: KeyboardEve
       setIsQuickSwitcherOpen(false);
       return;
     }
-    if (getAvailablePaneMagnificationController([
-      sftpPaneMagnificationRef?.current,
-      terminalPaneMagnificationRef?.current,
-    ])?.restore()) {
-      e.preventDefault();
-      e.stopPropagation();
-    }
   }
 }
 

application/app/AppPluginKeybindingHost.tsx

@@ -4,6 +4,8 @@ import { PluginContributionHost } from '../../components/plugins/PluginContribut
 import type { TerminalSession, Workspace } from '../../types';
 import { useActiveTabId } from '../state/activeTabStore';
 import { resolveActivePluginKeybindingContext } from '../state/pluginContributionContexts';
+import { getAISessionsSnapshot } from '../state/aiSessionsStore';
+import { getPersistedAiSessionsSnapshot } from '../state/aiStateSnapshots';
 
 /**
  * Leaf host for plugin keybindings so AppView does not subscribe to activeTabId.
@@ -23,11 +25,19 @@ export function AppPluginKeybindingHost({
   workspaces: Workspace[];
 }) {
   const activeTabId = useActiveTabId();
-  const keybindingContext = useMemo(() => resolveActivePluginKeybindingContext({
-    activeTabId,
-    sessions,
-    workspaces,
-  }), [activeTabId, sessions, workspaces]);
+  const keybindingContext = useMemo(() => {
+    // AI chat recency drives the workspace anchor fallback (#4098 phase 2).
+    // Read without subscribing: keybinding context is best-effort and refreshes
+    // on every tab/session/workspaces change that matters here.
+    const live = getAISessionsSnapshot().sessions;
+    const aiSessions = live.length > 0 ? live : getPersistedAiSessionsSnapshot();
+    return resolveActivePluginKeybindingContext({
+      activeTabId,
+      sessions,
+      workspaces,
+      aiSessions,
+    });
+  }, [activeTabId, sessions, workspaces]);
 
   return (
     <PluginContributionHost

application/app/AppSideEffects.paneMagnification.test.ts

@@ -4,12 +4,13 @@ import test from 'node:test';
 
 const source = readFileSync(new URL('./AppSideEffects.tsx', import.meta.url), 'utf8');
 
-test('terminal Escape restoration runs before xterm can stop propagation', () => {
-  const effectStart = source.indexOf("const onCaptureKeyDown = (e: KeyboardEvent) => {");
-  const effectSource = source.slice(effectStart, effectStart + 900);
+test('quick-switcher Escape handling stays in the bubble phase', () => {
+  const effectStart = source.indexOf('const onKeyDown = (e: KeyboardEvent) => {\n      _handleEscapeKeyDown(e);');
+  const effectEnd = source.indexOf('}, [appLockLocked]);', effectStart);
+  const effectSource = source.slice(effectStart, effectEnd);
 
   assert.notEqual(effectStart, -1);
-  assert.match(effectSource, /target\.closest\('\.xterm'\)/);
-  assert.match(effectSource, /window\.addEventListener\('keydown', onCaptureKeyDown, true\)/);
-  assert.match(effectSource, /window\.removeEventListener\('keydown', onCaptureKeyDown, true\)/);
+  assert.match(effectSource, /window\.addEventListener\('keydown', onKeyDown\)/);
+  assert.match(effectSource, /window\.removeEventListener\('keydown', onKeyDown\)/);
+  assert.doesNotMatch(source, /onCaptureKeyDown/);
 });

application/app/AppSideEffects.tsx

@@ -58,7 +58,9 @@ import {
 } from '../../domain/terminalAppearance';
 import { selectConnectionLogForTerminalDataCapture } from '../../domain/connectionLog';
 import { collectSessionIds } from '../../domain/workspace';
-import { resolveAgentHostWorkspace } from '../../domain/agentHostWorkspace';
+import { resolveAgentHostOpenWorkspace } from '../../domain/agentHostWorkspace';
+import { getAISessionsSnapshot } from '../state/aiSessionsStore';
+import { peekAgentRuntimeCleanup } from '../../infrastructure/ai/harness/agentRuntimeHandle';
 import { useHostOpenSessionReuse } from '../state/useHostOpenSessionReuse';
 import type { PaneMagnificationController } from '../../domain/paneMagnification';
 import { isPluginViewEditingTarget } from '../state/pluginKeybindings';
@@ -613,7 +615,7 @@ export function AppSideEffects() {
   const _handleTrayPanelConnect = useEffectEvent((hostId: string) => { return handleTrayPanelConnectImpl(() => ({ addConnectionLog, connectToHost, hostId, hosts, identities, keys, resolveEffectiveHost, resolveHostAuth, systemInfoRef, t, toast }), hostId); });
   const _handleTrayPanelConnectRequest = useEffectEvent((hostId: string) => { return handleTrayPanelConnectRequestImpl(() => ({ connectNow: _handleTrayPanelConnect, hostId, isVaultInitialized, queueConnect: (queuedHostId: string) => setPendingTrayPanelConnectHostIds((prev) => [...prev, queuedHostId]) }), hostId); });
   const _handleGlobalHotkeyKeyDown = useEffectEvent((e: KeyboardEvent) => { return handleGlobalHotkeyKeyDownImpl(() => ({ HOTKEY_DEBUG, closeTabKeyStr, e, executeHotkeyAction, hotkeyScheme, keyBindings, matchesKeyBinding }), e); });
-  const _handleEscapeKeyDown = useEffectEvent((e: KeyboardEvent) => { return handleEscapeKeyDownImpl(() => ({ e, isQuickSwitcherOpen, setIsQuickSwitcherOpen, sftpPaneMagnificationRef, terminalPaneMagnificationRef }), e); });
+  const _handleEscapeKeyDown = useEffectEvent((e: KeyboardEvent) => { return handleEscapeKeyDownImpl(() => ({ e, isQuickSwitcherOpen, setIsQuickSwitcherOpen }), e); });
 
   // Vault hosts for tray / auto-start; terminalHosts (vault + ephemeral) only for
   // dedicated transfer resume so quick-connect rows do not break tray connect.
@@ -1233,19 +1235,11 @@ export function AppSideEffects() {
 
   useEffect(() => {
     if (appLockLocked) return;
-    const onCaptureKeyDown = (e: KeyboardEvent) => {
-      if (e.key !== 'Escape') return;
-      const target = e.target;
-      if (!(target instanceof HTMLElement) || !target.closest('.xterm')) return;
-      _handleEscapeKeyDown(e);
-    };
     const onKeyDown = (e: KeyboardEvent) => {
       _handleEscapeKeyDown(e);
     };
-    window.addEventListener('keydown', onCaptureKeyDown, true);
     window.addEventListener('keydown', onKeyDown);
     return () => {
-      window.removeEventListener('keydown', onCaptureKeyDown, true);
       window.removeEventListener('keydown', onKeyDown);
     };
   }, [appLockLocked]);
@@ -1505,8 +1499,21 @@ export function AppSideEffects() {
     return sessionId;
   }, [handleConnectToHost, renameSessionInline]);
 
-  const openHostForVaultAgent = useCallback((host: Host, isExternalMcpCall: boolean, options?: { workspaceId?: string }) => {
-    const target = resolveAgentHostWorkspace(options?.workspaceId, activeTabStore.getActiveTabId(), workspaces.map(workspace => workspace.id));
+  const openHostForVaultAgent = useCallback((host: Host, isExternalMcpCall: boolean, options?: { workspaceId?: string; chatSessionId?: string }) => {
+    // A resumed history chat can run in a panel other than its saved binding.
+    // Prefer that turn's captured scope, never the window's current focus.
+    // Outside a running turn, retain the saved chat binding as the fallback.
+    const chat = options?.chatSessionId
+      ? getAISessionsSnapshot().sessions.find((session) => session.id === options.chatSessionId)
+      : undefined;
+    const turnScope = options?.chatSessionId
+      ? peekAgentRuntimeCleanup()?.getActiveScope?.(options.chatSessionId)
+      : undefined;
+    const target = resolveAgentHostOpenWorkspace(options?.workspaceId, turnScope ? { scope: turnScope } : chat, {
+      activeTabId: activeTabStore.getActiveTabId(),
+      workspaceIds: workspaces.map(workspace => workspace.id),
+      terminalSessions: sessionsRef.current,
+    });
     if (target.error) return { ok: false as const, error: target.error };
     // Silent sessions only apply to actual external MCP clients (chatSessionId
     // equals the reserved external-MCP scope). The in-app Catty AI chat's

application/app/AppView.tsx

@@ -264,7 +264,7 @@ function AppViewInner({ domains }: AppViewProps) {
   useMainWindowInputFocusRecovery({ onPageHidden: dismissTransientOverlays });
 
   const {
-    addShellHistoryEntry, clearAllCommandHistory, removeShellHistoryEntry, addSessionToWorkspace, addToWorkspaceDialog, appendHostToWorkspace, appendLocalTerminalToWorkspace,
+    addShellHistoryEntry, clearAllCommandHistory, removeShellHistoryEntry, addSessionToWorkspace, addToWorkspaceDialog, appendHostToWorkspace, appendLocalTerminalToWorkspace, moveWorkspacePane,
     clearAndRemoveSource, clearAndRemoveSources, closeLogView, closeSession, closeTabsBatch, closeWorkspace, commitPluginImporterData, commitVaultImportTransaction, commitVaultGroupMutation, copySessionToNewWindowWithCurrentShell, copySessionWithCurrentShell, duplicateSessionWithCurrentShell, copyWorkspaceWithCurrentShell,
     convertKnownHostToHost, createWorkspaceFromSessions, createWorkspaceFromTargets, createWorkspaceWithHosts,
     customGroups, currentTerminalTheme, deepLinkHostDraft, draggingSessionId, effectiveKnownHosts, editorTabs, editorWordWrap, emptyVaultConflict,
@@ -279,7 +279,7 @@ function AppViewInner({ domains }: AppViewProps) {
     resolveEmptyVaultConflict, resolveSessionAppearance, runSnippet, sessionLogsDir, sessionLogsEnabled, sessionLogsFormat, sessionLogsTimestampsEnabled, sessionRenameTarget, sshDebugLogsEnabled,
     sessions, setActiveTabId, setDeepLinkHostDraft, setDraggingSessionId, setEditorWordWrap,
     setNavigateToSection, setTerminalFontFamilyId, setTerminalFontSize, setVaultFocusRequest, updateSessionFontSize, updateSessionRestoreCwd, updateSessionDynamicTitle, updateSessionCodingCliProvider, clearSessionFontSizeOverride,
-    setWorkspaceFocusedSession, sftpAutoOpenSidebar, sftpFollowTerminalCwd, setSftpFollowTerminalCwd, sftpAutoSync, sftpDefaultViewMode, sftpDoubleClickBehavior,
+    setWorkspaceFocusedSession, setWorkspaceAnchorChat, sftpAutoOpenSidebar, sftpFollowTerminalCwd, setSftpFollowTerminalCwd, sftpAutoSync, sftpDefaultViewMode, sftpDoubleClickBehavior,
     sftpShowHiddenFiles, sftpUseCompressedUpload, snippetPackages, snippets, splitSessionWithCurrentShell, startSessionRename,
     startWorkspaceRename, submitSessionRename, submitWorkspaceRename, t, terminalFontFamilyId, terminalFontSize, terminalSettings, terminalThemeId, themeById,
     toggleBroadcast, toggleScriptsSidePanelRef, toggleSidePanelRef, terminalPaneMagnificationRef, sftpPaneMagnificationRef, toggleWorkspaceViewMode, unmanageSource,
@@ -774,12 +774,14 @@ function AppViewInner({ domains }: AppViewProps) {
           onTerminalDataCapture={handleTerminalDataCapture}
           onCreateWorkspaceFromSessions={createWorkspaceFromSessions}
           onAddSessionToWorkspace={addSessionToWorkspace}
+          onMoveWorkspacePane={moveWorkspacePane}
           onRequestAddToWorkspace={handleRequestAddToWorkspace}
           onAppendHostToWorkspace={handleAppendHostToWorkspace}
           onUpdateSplitSizes={updateSplitSizes}
           onSetDraggingSessionId={setDraggingSessionId}
           onToggleWorkspaceViewMode={toggleWorkspaceViewMode}
           onSetWorkspaceFocusedSession={setWorkspaceFocusedSession}
+          onSetWorkspaceAnchorChat={setWorkspaceAnchorChat}
           onReorderWorkspaceSessions={reorderWorkspaceSessions}
           onReorderTabs={reorderWorkTabs}
           onCopySession={copySessionWithCurrentShell}

application/app/SessionPublisher.workspaceActions.test.ts

@@ -0,0 +1,93 @@
+import assert from 'node:assert/strict';
+import { registerHooks } from 'node:module';
+import test from 'node:test';
+import React from 'react';
+import { act, create, type ReactTestRenderer } from 'react-test-renderer';
+import {
+  EMPTY_SESSION_SNAPSHOT,
+  getSessionSnapshotActions,
+  publishSessionSnapshot,
+} from '../state/sessionSnapshotStore';
+import { getAppShellPropsSnapshot } from './appShellPropsStore';
+import { registerAppHandlers } from './appHandlersBridge';
+
+// Keep both production publishers and the store between them real. Only the
+// state owner and unrelated theme side effects are replaced with fixtures.
+const sessionFixtureUrl = `data:text/javascript,${encodeURIComponent(`
+  let session;
+  export function setSession(value) { session = value; }
+  export function useSessionState() { return session; }
+`)}`;
+const themeFixtureUrl = `data:text/javascript,${encodeURIComponent(`
+  const noop = () => {};
+  const theme = {};
+  const runtime = {
+    globalAppearance: theme, accentedGlobalAppearance: theme,
+    clearIntent: noop, settleManualIntent: noop, pickTheme: noop,
+    resolveFocusedAppearance: noop, currentTerminalTheme: theme,
+  };
+  export function useThemeRuntime() { return runtime; }
+  export function useTerminalAppearanceInjection() {}
+`)}`;
+registerHooks({
+  resolve(specifier, context, nextResolve) {
+    if (specifier === '../../state/useSessionState' && context.parentURL?.endsWith('/SessionPublisher.tsx')) {
+      return { url: sessionFixtureUrl, shortCircuit: true };
+    }
+    if (specifier === '../../state/useThemeRuntime' && context.parentURL?.endsWith('/TerminalHost.tsx')) {
+      return { url: themeFixtureUrl, shortCircuit: true };
+    }
+    return nextResolve(specifier, context);
+  },
+});
+
+const { setSession } = await import(sessionFixtureUrl);
+const { SessionPublisher } = await import('./publishers/SessionPublisher');
+const { TerminalHost } = await import('./hosts/TerminalHost');
+
+test('workspace actions reach the terminal shell through SessionPublisher and TerminalHost', async (t) => {
+  const previousActEnvironment = Object.getOwnPropertyDescriptor(globalThis, 'IS_REACT_ACT_ENVIRONMENT');
+  Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', { configurable: true, value: true });
+  let renderer: ReactTestRenderer | undefined;
+  t.after(async () => {
+    await act(async () => renderer?.unmount());
+    registerAppHandlers(null);
+    publishSessionSnapshot(EMPTY_SESSION_SNAPSHOT);
+    if (previousActEnvironment) Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', previousActEnvironment);
+    else Reflect.deleteProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT');
+  });
+
+  const calls: unknown[][] = [];
+  const moveWorkspacePane = (...args: unknown[]) => calls.push(['move', ...args]);
+  const setWorkspaceAnchorChat = (...args: unknown[]) => calls.push(['anchor', ...args]);
+  setSession({ ...EMPTY_SESSION_SNAPSHOT, moveWorkspacePane, setWorkspaceAnchorChat });
+  registerAppHandlers({});
+  const renderTree = () => React.createElement(
+    SessionPublisher,
+    { persistSessionRestore: false },
+    React.createElement(TerminalHost),
+  );
+  await act(async () => { renderer = create(renderTree()); });
+
+  assert.equal(getSessionSnapshotActions()?.moveWorkspacePane, moveWorkspacePane);
+  assert.equal(getSessionSnapshotActions()?.setWorkspaceAnchorChat, setWorkspaceAnchorChat);
+  const terminal = getAppShellPropsSnapshot().domains?.terminal;
+  assert.equal(terminal?.moveWorkspacePane, moveWorkspacePane);
+  assert.equal(terminal?.setWorkspaceAnchorChat, setWorkspaceAnchorChat);
+  const hint = { direction: 'horizontal', position: 'top', targetSessionId: 'pane-b' };
+  (terminal?.moveWorkspacePane as typeof moveWorkspacePane)('workspace', 'pane-a', hint);
+  (terminal?.setWorkspaceAnchorChat as typeof setWorkspaceAnchorChat)('workspace', 'chat');
+  assert.deepEqual(calls, [
+    ['move', 'workspace', 'pane-a', hint],
+    ['anchor', 'workspace', 'chat'],
+  ]);
+
+  // A changed state-owner callback must not be trapped in a stale memoized
+  // action bag even when all session/workspace snapshots stay identical.
+  const replacementMove = (...args: unknown[]) => calls.push(['replacement-move', ...args]);
+  const replacementAnchor = (...args: unknown[]) => calls.push(['replacement-anchor', ...args]);
+  setSession({ ...EMPTY_SESSION_SNAPSHOT, moveWorkspacePane: replacementMove, setWorkspaceAnchorChat: replacementAnchor });
+  await act(async () => renderer!.update(renderTree()));
+  assert.equal(getAppShellPropsSnapshot().domains?.terminal.moveWorkspacePane, replacementMove);
+  assert.equal(getAppShellPropsSnapshot().domains?.terminal.setWorkspaceAnchorChat, replacementAnchor);
+});

application/app/hosts/TerminalHost.tsx

@@ -170,6 +170,7 @@ export function TerminalHost() {
     if (!handlers) return null;
     return {
       addSessionToWorkspace: sessionActions?.addSessionToWorkspace,
+      moveWorkspacePane: sessionActions?.moveWorkspacePane,
       appendHostToWorkspace: sessionActions?.appendHostToWorkspace,
       appendLocalTerminalToWorkspace: sessionActions?.appendLocalTerminalToWorkspace,
       clearSessionFontSizeOverride: sessionActions?.clearSessionFontSizeOverride,
@@ -227,6 +228,7 @@ export function TerminalHost() {
       setTerminalFontFamilyId: terminalSettingsActions?.setTerminalFontFamilyId,
       setTerminalFontSize: terminalSettingsActions?.setTerminalFontSize,
       setWorkspaceFocusedSession: sessionActions?.setWorkspaceFocusedSession,
+      setWorkspaceAnchorChat: sessionActions?.setWorkspaceAnchorChat,
       sftpAutoOpenSidebar: terminalSettings.sftpAutoOpenSidebar,
       sftpFollowTerminalCwd: terminalSettings.sftpFollowTerminalCwd,
       setSftpFollowTerminalCwd: terminalSettingsActions?.setSftpFollowTerminalCwd,

application/app/publishers/SessionPublisher.tsx

@@ -48,6 +48,7 @@ export function SessionPublisher({ persistSessionRestore, children }: SessionPub
     resetWorkspaceRename,
     removeSessionFromWorkspace,
     setWorkspaceFocusedSession,
+    setWorkspaceAnchorChat,
     toggleWorkspaceViewMode,
     createLocalTerminal,
     createSerialSession,
@@ -58,6 +59,7 @@ export function SessionPublisher({ persistSessionRestore, children }: SessionPub
     createWorkspaceWithHosts,
     createWorkspaceFromSessions,
     addSessionToWorkspace,
+    moveWorkspacePane,
     appendHostToWorkspace,
     appendHostToWorkspaceConfirmed,
     appendLocalTerminalToWorkspace,
@@ -133,6 +135,7 @@ export function SessionPublisher({ persistSessionRestore, children }: SessionPub
     resetWorkspaceRename,
     removeSessionFromWorkspace,
     setWorkspaceFocusedSession,
+    setWorkspaceAnchorChat,
     toggleWorkspaceViewMode,
     createLocalTerminal,
     createSerialSession,
@@ -143,6 +146,7 @@ export function SessionPublisher({ persistSessionRestore, children }: SessionPub
     createWorkspaceWithHosts,
     createWorkspaceFromSessions,
     addSessionToWorkspace,
+    moveWorkspacePane,
     appendHostToWorkspace,
     appendHostToWorkspaceConfirmed,
     appendLocalTerminalToWorkspace,
@@ -172,6 +176,7 @@ export function SessionPublisher({ persistSessionRestore, children }: SessionPub
     updateSessionCodingCliProvider,
   }), [
     addSessionToWorkspace,
+    moveWorkspacePane,
     appendHostToWorkspace,
     appendHostToWorkspaceConfirmed,
     appendLocalTerminalToWorkspace,
@@ -208,6 +213,7 @@ export function SessionPublisher({ persistSessionRestore, children }: SessionPub
     setActiveTabId,
     setDraggingSessionId,
     setWorkspaceFocusedSession,
+    setWorkspaceAnchorChat,
     splitSession,
     startSessionRename,
     startWorkspaceRename,

application/convergentSyncMigration.test.ts

@@ -21,13 +21,20 @@ Object.defineProperty(globalThis, 'localStorage', {
 });
 
 const {
+  applyLegacySyncPayload,
+  convergentConflictAddressKey,
+  createConvergentSyncStateFromPayload,
+  dotKey,
+  mergeConvergentSyncStates,
   planConvergentSyncMigration,
+  refreshConvergentSyncMigrationPlan,
   stripConvergentSyncEnvelope,
 } = await import('../domain/convergentSync/index.ts');
 const { getConvergentSyncLocalConfig } = await import('../infrastructure/services/convergentSyncConfig.ts');
 const {
   initializePreparedConvergentMigration,
   prepareConvergentSyncMigration,
+  resolvePreparedConvergentMigrationConflict,
 } = await import('./convergentSyncMigration.ts');
 
 function payload(): SyncPayload {
@@ -44,6 +51,42 @@ test.beforeEach(() => {
   localStorageValues.clear();
 });
 
+test('preview resolution uses the manager device identity and only updates the prepared plan', () => {
+  const baseline: SyncPayload = { ...payload(), settings: { theme: 'system' } };
+  const base = createConvergentSyncStateFromPayload(baseline, 'seed', NOW);
+  const state = mergeConvergentSyncStates(
+    applyLegacySyncPayload(base, baseline, { ...baseline, settings: { theme: 'light' } }, 'left', NOW + 1),
+    applyLegacySyncPayload(base, baseline, { ...baseline, settings: { theme: 'dark' } }, 'right', NOW + 2),
+  );
+  const plan = refreshConvergentSyncMigrationPlan(planConvergentSyncMigration({
+    localPayload: baseline, localTrustedBaseline: null, providers: [], deviceId: 'local', now: NOW,
+  }), state);
+  const prepared = { plan, localSnapshot: baseline, providerBaselines: [] };
+  const conflict = plan.preview.conflicts[0];
+  const addressKey = convergentConflictAddressKey(conflict.address);
+  const selected = conflict.candidates.find((candidate) => candidate.value === 'light')!;
+  const manager = { getState: () => ({ deviceId: 'resolver' }) } as unknown as CloudSyncManager;
+  const resolved = resolvePreparedConvergentMigrationConflict(
+    prepared, addressKey, dotKey(selected.dot), manager, NOW + 3,
+  );
+
+  assert.equal(resolved.plan.preview.canInitialize, true);
+  assert.equal(resolved.plan.preview.conflictCount, 0);
+  assert.deepEqual(resolved.plan.preview.blockedReasons, []);
+  assert.equal(resolved.plan.payload?.settings?.theme, 'light');
+  assert.ok(resolved.plan.state?.vector.resolver);
+  assert.equal(resolved.localSnapshot, prepared.localSnapshot);
+  assert.equal(resolved.providerBaselines, prepared.providerBaselines);
+  assert.equal(prepared.plan.preview.conflictCount, 1);
+  assert.equal(prepared.plan.payload, null);
+  assert.throws(() => resolvePreparedConvergentMigrationConflict(
+    prepared, 'missing', dotKey(selected.dot), manager,
+  ), /conflict no longer exists/);
+  assert.throws(() => resolvePreparedConvergentMigrationConflict(
+    prepared, addressKey, 'missing', manager,
+  ), /candidate no longer exists/);
+});
+
 test('preparation seeds a trusted baseline for an unchanged v1 provider', async () => {
   const remotePayload: SyncPayload = {
     ...payload(),

application/convergentSyncMigration.ts

@@ -6,8 +6,11 @@ import type {
 } from '../domain/sync';
 import {
   cloudSyncPayloadsEqual,
+  convergentConflictAddressKey,
   materializeSyncPayloadFromConvergentState,
   planConvergentSyncMigration,
+  refreshConvergentSyncMigrationPlan,
+  resolveConvergentFieldConflict,
   stripConvergentSyncEnvelope,
   validateConvergentSyncPayload,
   type ConvergentMigrationPlan,
@@ -25,6 +28,25 @@ export interface PreparedConvergentMigration {
   localSnapshot: SyncPayload;
 }
 
+export function resolvePreparedConvergentMigrationConflict(
+  prepared: PreparedConvergentMigration,
+  addressKey: string,
+  candidateDot: string,
+  manager: CloudSyncManager = getCloudSyncManager(),
+  now = Date.now(),
+): PreparedConvergentMigration {
+  const conflict = prepared.plan.preview.conflicts.find(
+    (entry) => convergentConflictAddressKey(entry.address) === addressKey,
+  );
+  if (!prepared.plan.state || !conflict) {
+    throw new Error('The convergent migration conflict no longer exists');
+  }
+  const state = resolveConvergentFieldConflict(
+    prepared.plan.state, conflict, candidateDot, manager.getState().deviceId, now,
+  );
+  return { ...prepared, plan: refreshConvergentSyncMigrationPlan(prepared.plan, state) };
+}
+
 interface LegacyProviderBaselineSeed {
   provider: CloudProvider;
   remoteVersion: number;

application/i18n/locales/en/ai.ts

@@ -99,6 +99,7 @@ export const enAiMessages: Messages = {
   'ai.providers.advancedParams.hint': 'Leave blank to use provider defaults.',
   'ai.providers.advancedParams.maxTokens.placeholder': 'e.g. 4096',
   'ai.providers.advancedParams.default': 'Provider default',
+  'ai.providers.advancedParams.reasoningEffort.help': 'xhigh and max are only sent when the selected model supports them; otherwise they are clamped to the deepest supported level.',
 
   // AI Codex
   'ai.codex': 'Codex',
@@ -660,6 +661,10 @@ export const enAiMessages: Messages = {
   'ai.chatShortcuts.title': 'Chat Shortcuts',
   'ai.chatShortcuts.selectionAction': 'Show Add to Conversation when selecting terminal text',
   'ai.chatShortcuts.selectionAction.description': 'Show a small AI button next to selected terminal text.',
+  'ai.chatHistory.title': 'Chat History',
+  'ai.chatHistory.messageCap': 'Messages kept per chat',
+  'ai.chatHistory.messageCap.description': 'Maximum number of messages stored per chat (50–2000). Lowering it drops the oldest messages from storage on the next write. Larger values increase storage and cloud-sync size.',
+  'ai.chatHistory.messageCap.unit': 'messages',
 
   // AI Error
   'ai.codex.bridgeError': 'Codex main-process handlers are not loaded yet. Fully restart Netcatty, or restart the Electron dev process, then try again.',
@@ -715,6 +720,8 @@ export const enAiMessages: Messages = {
 
   // Unified tooltips for terminal workspace and top tabs (issue #954)
   'terminal.layer.addTerminal': 'Add Terminal',
+  'terminal.layer.emptyWorkspace': 'No terminals in this workspace',
+  'terminal.layer.emptyWorkspaceHint': 'Add a local terminal or connect to a host to get started.',
   'terminal.layer.switchToSplitView': 'Switch to Split View',
   'terminal.layer.sftp': 'SFTP',
   'terminal.layer.scripts': 'Scripts',

application/i18n/locales/en/core.ts

@@ -1,6 +1,44 @@
 import type { Messages } from '../types';
 
 export const enCoreMessages: Messages = {
+  "settings.plugins.github.install": "Install from GitHub",
+  "settings.plugins.github.description": "Download a published .ncpkg release, then review its source and permissions.",
+  "settings.plugins.github.repository": "GitHub repository",
+  "settings.plugins.github.formats": "Accepts https://github.com/owner/repo, github.com/owner/repo or owner/repo.",
+  "settings.plugins.github.busy": "Downloading, validating or installing the package...",
+  "settings.plugins.github.review": "Repository ownership and package integrity do not verify publisher trust. No build scripts run. The plugin installs disabled; review permission modes before enabling.",
+  "settings.plugins.github.accept": "I trust this repository and have reviewed the declared permissions.",
+  "settings.plugins.github.confirm": "Install disabled",
+  "settings.plugins.github.download": "Download and review",
+  "settings.plugins.github.error.invalidRepository": "Enter https://github.com/owner/repo, github.com/owner/repo or owner/repo (repository only; no credentials, query, fragment or extra paths).",
+  "settings.plugins.github.error.unavailable": "GitHub plugin installation is unavailable in this session.",
+  "settings.plugins.github.error.reviewFirst": "Download and review a GitHub plugin first.",
+  "settings.plugins.github.error.network": "Cannot reach GitHub. Check your network connection and try again.",
+  "settings.plugins.github.error.timeout": "The GitHub download timed out. Please try again.",
+  "settings.plugins.github.error.rateLimit": "GitHub API rate limit reached. Try again later.",
+  "settings.plugins.github.error.notFound": "GitHub repository or asset not found. Only accessible public repositories are supported; import private packages locally.",
+  "settings.plugins.github.error.accessDenied": "GitHub access denied. Private repositories and sign-in are not supported.",
+  "settings.plugins.github.error.http": "GitHub download failed (HTTP {status}). Please try again later.",
+  "settings.plugins.github.error.moved": "This GitHub repository has moved. Enter its current repository URL.",
+  "settings.plugins.github.error.redirect": "The GitHub download redirect could not be verified. Download a trusted .ncpkg package and import it locally.",
+  "settings.plugins.github.error.noRelease": "This repository has no published stable release. Ask the author to publish one with a .ncpkg asset, or import a built package locally.",
+  "settings.plugins.github.error.noAsset": "This release has no .ncpkg asset. Ask the author to build and attach one; Netcatty cannot build source repositories.",
+  "settings.plugins.github.error.multipleAssets": "This release contains multiple .ncpkg assets. Download the intended package and import it locally.",
+  "settings.plugins.github.error.metadata": "The GitHub release metadata is invalid. Ask the author to check the release, tag and .ncpkg asset.",
+  "settings.plugins.github.error.identity": "The package does not match the selected GitHub repository and release. Installation was stopped.",
+  "settings.plugins.github.error.commit": "The release tag has no accessible commit. Ask the author to repair the release tag.",
+  "settings.plugins.github.error.size": "The GitHub package size is invalid or exceeds the download limit.",
+  "settings.plugins.github.error.integrity": "The downloaded package failed its size or SHA-256 check. Download and review it again.",
+  "settings.plugins.github.error.package": "GitHub did not return a valid .ncpkg ZIP package or release metadata. Ask the author to check the release asset.",
+  "settings.plugins.github.error.busy": "A GitHub plugin operation is already active. Close the preview and try again.",
+  "settings.plugins.github.error.expired": "The GitHub package preview expired. Download and review it again.",
+  "settings.plugins.github.error.advanced": "This package requires advanced developer mode. Normal plugin management accepts browser-only packages.",
+  "settings.plugins.github.error.incompatible": "This plugin is incompatible with this version of Netcatty. Check the technical details with the author.",
+  "settings.plugins.github.error.source": "This plugin is already bound to another source. Uninstall it and explicitly clear its old source data before changing sources.",
+  "settings.plugins.github.error.failed": "The plugin could not be validated or installed. Check the technical details before trying again.",
+  "settings.plugins.github.error.details": "Technical details",
+
+
   "settings.plugins.landing.checkUpdates": "Check for updates",
   "settings.plugins.landing.checkingUpdates": "Checking…",
   "settings.plugins.landing.updateSummary": "Checked: {checked} · Published updates: {updates} · Not checked: {skipped}.",

application/i18n/locales/en/terminal.ts

@@ -1,6 +1,24 @@
 import type { Messages } from '../types';
 
 export const enTerminalMessages: Messages = {
+  'terminal.directory.open': 'Current directory: {path}. Change directory',
+  'terminal.directory.unknown': 'Directory unknown',
+  'terminal.directory.search': 'Search child directories...',
+  'terminal.directory.directories': 'Directories',
+  'terminal.directory.parent': '.. (Parent directory)',
+  'terminal.directory.loading': 'Reading directories...',
+  'terminal.directory.empty': 'No child directories',
+  'terminal.directory.noMatches': 'No matching directories',
+  'terminal.directory.hidden': 'Show hidden directories',
+  'terminal.directory.refresh': 'Refresh',
+  'terminal.directory.unavailable': 'Directory navigation is unavailable for this session.',
+  'terminal.directory.busy': 'Wait for an empty shell prompt.',
+  'terminal.directory.readFailed': 'Could not read this directory. Try refreshing.',
+  'terminal.directory.changeFailed': 'Could not confirm the directory change. Refresh before retrying.',
+  'terminal.directory.unsupportedPath': 'This directory name cannot be sent safely to the terminal.',
+  'settings.terminal.behavior.contextChips': 'Context Chips',
+  'settings.terminal.behavior.contextChips.desc': 'Show the context toolbar below quick commands in the compose bar.',
+
   'terminal.toolbar.openSessionLog': 'Open session log',
   'terminal.toolbar.sessionLogActions': 'Session log actions',
   'terminal.toolbar.sessionLog.menu': 'Session log',

application/i18n/locales/en/vault.ts

@@ -316,7 +316,26 @@ export const enVaultMessages: Messages = {
   'sftp.extract.extracting': 'Extracting {fileName}...',
   'sftp.extract.success': 'Extracted {fileName}',
   'sftp.extract.error': 'Failed to extract {fileName}: {error}',
+  'sftp.archive.action': 'Compress...',
+  'sftp.archive.title': 'Compress files',
+  'sftp.archive.description': 'Create an archive on the server from {count} selected items.',
+  'sftp.archive.name': 'Archive name',
+  'sftp.archive.format': 'Format',
+  'sftp.archive.destination': 'Save in',
+  'sftp.archive.create': 'Compress',
+  'sftp.archive.creating': 'Compressing...',
+  'sftp.archive.overwriteTitle': 'Replace existing archive?',
+  'sftp.archive.overwriteDescription': 'An archive named "{name}" already exists. Confirm to replace it with the new archive.',
+  'sftp.archive.overwrite': 'Replace and compress',
+  'sftp.archive.failed': 'Failed to create archive',
+  'sftp.archive.invalidSelection': 'Cannot compress this selection',
+  'sftp.archive.invalidName': 'Enter a valid file name without a directory path.',
+  'sftp.archive.invalidExtension': 'The file extension must match the selected format.',
+  'sftp.archive.connectionChanged': 'The connection has changed. Select the files again.',
+  'sftp.archive.unavailable': 'Archive creation is unavailable for this connection.',
+  'sftp.archive.success': 'Created {fileName}',
   'sftp.context.copyToOtherPane': 'Copy to other pane',
+  'sftp.context.duplicate': 'Duplicate',
   'sftp.copyToOtherPane.unavailable': 'Open the two-pane SFTP view and connect the destination pane before copying files.',
   'sftp.copyCurrentPath': 'Copy current path',
   'sftp.copyCurrentPath.success': 'Current path copied',

application/i18n/locales/es/ai.ts

@@ -90,6 +90,7 @@ export const esAiMessages: Messages = {
   'ai.providers.advancedParams.hint': 'Déjalo en blanco para usar los valores predeterminados del proveedor.',
   'ai.providers.advancedParams.maxTokens.placeholder': 'p. ej. 4096',
   'ai.providers.advancedParams.default': 'Predeterminado del proveedor',
+  'ai.providers.advancedParams.reasoningEffort.help': 'xhigh y max solo se envían cuando el modelo elegido los admite; de lo contrario se ajustan al nivel más profundo compatible.',
   'ai.providers.headers': 'Cabeceras HTTP personalizadas',
   'ai.providers.headers.help': 'Cabeceras opcionales para este proveedor. Los valores se ocultan y se cifran al guardarlos.',
   'ai.providers.headers.name': 'Nombre de la cabecera',
@@ -660,6 +661,10 @@ export const esAiMessages: Messages = {
   'ai.chatShortcuts.title': 'Atajos de chat',
   'ai.chatShortcuts.selectionAction': 'Mostrar "Agregar a la conversación" al seleccionar texto de la terminal',
   'ai.chatShortcuts.selectionAction.description': 'Muestra un pequeño botón de IA junto al texto seleccionado de la terminal.',
+  'ai.chatHistory.title': 'Historial de chat',
+  'ai.chatHistory.messageCap': 'Mensajes conservados por chat',
+  'ai.chatHistory.messageCap.description': 'Número máximo de mensajes almacenados por chat (50–2000). Al reducirlo, los mensajes más antiguos se descartan del almacenamiento en la siguiente escritura. Los valores más altos aumentan el almacenamiento y el tamaño de la sincronización en la nube.',
+  'ai.chatHistory.messageCap.unit': 'mensajes',
 
   // AI Error
   'ai.codex.bridgeError': 'Los controladores del proceso principal de Codex aún no están cargados. Reinicia Netcatty por completo o reinicia el proceso de desarrollo de Electron y vuelve a intentarlo.',
@@ -715,6 +720,8 @@ export const esAiMessages: Messages = {
 
   // Unified tooltips for terminal workspace and top tabs (issue #954)
   'terminal.layer.addTerminal': 'Agregar terminal',
+  'terminal.layer.emptyWorkspace': 'No hay terminales en este espacio de trabajo',
+  'terminal.layer.emptyWorkspaceHint': 'Agrega un terminal local o conecta un host para comenzar.',
   'terminal.layer.switchToSplitView': 'Cambiar a vista dividida',
   'terminal.layer.sftp': 'SFTP',
   'terminal.layer.scripts': 'Scripts',

application/i18n/locales/es/core.ts

@@ -1,6 +1,44 @@
 import type { Messages } from '../types';
 
 export const esCoreMessages: Messages = {
+  "settings.plugins.github.install": "Instalar desde GitHub",
+  "settings.plugins.github.description": "Descarga una versión .ncpkg publicada y revisa su origen y permisos.",
+  "settings.plugins.github.repository": "Repositorio de GitHub",
+  "settings.plugins.github.formats": "Acepta https://github.com/owner/repo, github.com/owner/repo u owner/repo.",
+  "settings.plugins.github.busy": "Descargando, validando o instalando el paquete...",
+  "settings.plugins.github.review": "El origen y la integridad no verifican la confianza en el autor. No se ejecutan scripts de compilación. Se instala desactivado; revisa los permisos antes de activarlo.",
+  "settings.plugins.github.accept": "Confío en este repositorio y he revisado los permisos declarados.",
+  "settings.plugins.github.confirm": "Instalar desactivado",
+  "settings.plugins.github.download": "Descargar y revisar",
+  "settings.plugins.github.error.invalidRepository": "Introduce https://github.com/owner/repo, github.com/owner/repo u owner/repo. Usa solo el repositorio, sin credenciales, parámetros, fragmentos ni rutas adicionales.",
+  "settings.plugins.github.error.unavailable": "La instalación de plugins desde GitHub no está disponible en esta sesión.",
+  "settings.plugins.github.error.reviewFirst": "Primero descarga y revisa un plugin de GitHub.",
+  "settings.plugins.github.error.network": "No se puede conectar con GitHub. Comprueba tu conexión e inténtalo de nuevo.",
+  "settings.plugins.github.error.timeout": "La descarga de GitHub agotó el tiempo de espera. Inténtalo de nuevo.",
+  "settings.plugins.github.error.rateLimit": "Se alcanzó el límite de solicitudes de la API de GitHub. Inténtalo más tarde.",
+  "settings.plugins.github.error.notFound": "No se encontró el repositorio o archivo de GitHub. Solo se admiten repositorios públicos accesibles; importa los paquetes privados desde un archivo local.",
+  "settings.plugins.github.error.accessDenied": "GitHub denegó el acceso. No se admiten repositorios privados ni inicio de sesión.",
+  "settings.plugins.github.error.http": "La descarga de GitHub falló (HTTP {status}). Inténtalo más tarde.",
+  "settings.plugins.github.error.moved": "Este repositorio de GitHub se ha movido. Introduce su dirección actual.",
+  "settings.plugins.github.error.redirect": "No se pudo verificar la redirección de GitHub. Descarga un paquete .ncpkg de confianza e impórtalo desde un archivo local.",
+  "settings.plugins.github.error.noRelease": "Este repositorio no tiene una versión estable publicada. Pide al autor que publique una con un archivo .ncpkg o importa un paquete compilado local.",
+  "settings.plugins.github.error.noAsset": "Esta versión no incluye un archivo .ncpkg. Pide al autor que lo compile y adjunte; Netcatty no puede compilar repositorios de código fuente.",
+  "settings.plugins.github.error.multipleAssets": "Esta versión contiene varios archivos .ncpkg. Descarga el paquete deseado e impórtalo desde un archivo local.",
+  "settings.plugins.github.error.metadata": "Los metadatos de la versión de GitHub no son válidos. Pide al autor que revise la versión, la etiqueta y el archivo .ncpkg.",
+  "settings.plugins.github.error.identity": "El paquete no coincide con el repositorio y la versión de GitHub seleccionados. Se detuvo la instalación.",
+  "settings.plugins.github.error.commit": "La etiqueta de la versión no tiene un commit accesible. Pide al autor que corrija la etiqueta.",
+  "settings.plugins.github.error.size": "El tamaño del paquete de GitHub no es válido o supera el límite de descarga.",
+  "settings.plugins.github.error.integrity": "El paquete descargado no superó la comprobación de tamaño o SHA-256. Descárgalo y revísalo de nuevo.",
+  "settings.plugins.github.error.package": "GitHub no devolvió un paquete ZIP .ncpkg o metadatos de versión válidos. Pide al autor que revise el archivo publicado.",
+  "settings.plugins.github.error.busy": "Ya hay una operación de plugin de GitHub en curso. Cierra la vista previa e inténtalo de nuevo.",
+  "settings.plugins.github.error.expired": "La vista previa del paquete de GitHub caducó. Descárgalo y revísalo de nuevo.",
+  "settings.plugins.github.error.advanced": "Este paquete requiere el modo de desarrollo avanzado. La gestión normal solo admite paquetes para navegador.",
+  "settings.plugins.github.error.incompatible": "Este plugin no es compatible con esta versión de Netcatty. Consulta los detalles técnicos con el autor.",
+  "settings.plugins.github.error.source": "Este plugin ya está vinculado a otro origen. Desinstálalo y borra explícitamente los datos del origen anterior antes de cambiarlo.",
+  "settings.plugins.github.error.failed": "No se pudo validar o instalar el plugin. Revisa los detalles técnicos antes de intentarlo de nuevo.",
+  "settings.plugins.github.error.details": "Detalles técnicos",
+
+
   "settings.plugins.landing.checkUpdates": "Buscar actualizaciones",
   "settings.plugins.landing.checkingUpdates": "Buscando…",
   "settings.plugins.landing.updateSummary": "Comprobados: {checked} · Actualizaciones publicadas: {updates} · Sin comprobar: {skipped}.",

application/i18n/locales/es/terminal.ts

@@ -1,6 +1,24 @@
 import type { Messages } from '../types';
 
 export const esTerminalMessages: Messages = {
+  'terminal.directory.open': 'Directorio actual: {path}. Cambiar directorio',
+  'terminal.directory.unknown': 'Directorio desconocido',
+  'terminal.directory.search': 'Buscar subdirectorios...',
+  'terminal.directory.directories': 'Directorios',
+  'terminal.directory.parent': '.. (Directorio padre)',
+  'terminal.directory.loading': 'Leyendo directorios...',
+  'terminal.directory.empty': 'Sin subdirectorios',
+  'terminal.directory.noMatches': 'Sin directorios coincidentes',
+  'terminal.directory.hidden': 'Mostrar directorios ocultos',
+  'terminal.directory.refresh': 'Actualizar',
+  'terminal.directory.unavailable': 'La navegación de directorios no está disponible para esta sesión.',
+  'terminal.directory.busy': 'Espera a que el prompt esté vacío.',
+  'terminal.directory.readFailed': 'No se pudo leer el directorio. Actualiza e inténtalo de nuevo.',
+  'terminal.directory.changeFailed': 'No se pudo confirmar el cambio. Actualiza antes de reintentar.',
+  'terminal.directory.unsupportedPath': 'No se puede enviar este nombre de directorio de forma segura.',
+  'settings.terminal.behavior.contextChips': 'Context Chips',
+  'settings.terminal.behavior.contextChips.desc': 'Mostrar la barra de contexto debajo de los comandos rápidos.',
+
   'terminal.toolbar.openSessionLog': 'Abrir registro de sesión',
   'terminal.toolbar.sessionLogActions': 'Acciones del registro',
   'terminal.toolbar.sessionLog.menu': 'Registro de sesión',

application/i18n/locales/es/vault.ts

@@ -316,7 +316,26 @@ export const esVaultMessages: Messages = {
   'sftp.extract.extracting': 'Extrayendo {fileName}...',
   'sftp.extract.success': 'Se extrajo {fileName}',
   'sftp.extract.error': 'No se pudo extraer {fileName}: {error}',
+  'sftp.archive.action': 'Comprimir...',
+  'sftp.archive.title': 'Comprimir archivos',
+  'sftp.archive.description': 'Crea un archivo comprimido en el servidor con los {count} elementos seleccionados.',
+  'sftp.archive.name': 'Nombre del archivo comprimido',
+  'sftp.archive.format': 'Formato',
+  'sftp.archive.destination': 'Guardar en',
+  'sftp.archive.create': 'Comprimir',
+  'sftp.archive.creating': 'Comprimiendo...',
+  'sftp.archive.overwriteTitle': '¿Reemplazar el archivo comprimido existente?',
+  'sftp.archive.overwriteDescription': 'Ya existe un archivo comprimido llamado "{name}". Confirma para reemplazarlo por el nuevo.',
+  'sftp.archive.overwrite': 'Reemplazar y comprimir',
+  'sftp.archive.failed': 'No se pudo crear el archivo comprimido',
+  'sftp.archive.invalidSelection': 'No se puede comprimir esta selección',
+  'sftp.archive.invalidName': 'Ingresa un nombre de archivo válido sin una ruta de directorio.',
+  'sftp.archive.invalidExtension': 'La extensión del archivo debe coincidir con el formato seleccionado.',
+  'sftp.archive.connectionChanged': 'La conexión cambió. Vuelve a seleccionar los archivos.',
+  'sftp.archive.unavailable': 'No se pueden crear archivos comprimidos en esta conexión.',
+  'sftp.archive.success': 'Se creó {fileName}',
   'sftp.context.copyToOtherPane': 'Copiar al otro panel',
+  'sftp.context.duplicate': 'Duplicar',
   'sftp.copyToOtherPane.unavailable': 'Abre la vista SFTP de dos paneles y conecta el panel de destino antes de copiar archivos.',
   'sftp.copyCurrentPath': 'Copiar ruta actual',
   'sftp.copyCurrentPath.success': 'Ruta actual copiada',

application/i18n/locales/pluginGitHubInstallLocales.test.ts

@@ -0,0 +1,30 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { SUPPORTED_UI_LOCALES } from '../../../infrastructure/config/i18n';
+import { getLoadedLocaleMessages, loadLocaleMessages } from '../messages';
+import en from './en';
+import { describePluginGitHubInstallError } from '../../../domain/pluginGitHubInstallError';
+
+test('GitHub install copy and error interpolation are complete in every supported UI locale', async () => {
+  const keys = Object.keys(en).filter(key => key.startsWith('settings.plugins.github.'));
+  assert.ok(keys.length > 30);
+  for (const { id } of SUPPORTED_UI_LOCALES) {
+    await loadLocaleMessages(id);
+    const messages = getLoadedLocaleMessages(id)!;
+    for (const key of keys) {
+      assert.ok(messages[key]?.trim(), `${id}: ${key}`);
+      assert.deepEqual(messages[key].match(/\{\w+\}/g) ?? [], en[key].match(/\{\w+\}/g) ?? [], `${id}: ${key}`);
+    }
+  }
+});
+
+test('GitHub error presentation handles Electron wrappers, HTTP status and diagnostic fallback', () => {
+  const expired = describePluginGitHubInstallError("Error invoking remote method 'plugins:github:install': Error: GitHub package preview expired. Download and review it again");
+  assert.equal(expired.key, 'settings.plugins.github.error.expired');
+  assert.equal(expired.details, null);
+  assert.deepEqual(describePluginGitHubInstallError('GitHub download failed (HTTP 503)').values, { status: '503' });
+  const validator = 'manifest version must be a semantic version';
+  assert.equal(describePluginGitHubInstallError(validator).details, validator);
+  assert.equal(describePluginGitHubInstallError(validator).key, 'settings.plugins.github.error.failed');
+  assert.equal(describePluginGitHubInstallError('Plugin is incompatible: engine version').key, 'settings.plugins.github.error.incompatible');
+});

application/i18n/locales/ru/ai.ts

@@ -71,6 +71,7 @@ export const ruAiMessages: Messages = {
   'ai.providers.advancedParams.hint': 'Оставьте пустым, чтобы использовать настройки провайдера по умолчанию.',
   'ai.providers.advancedParams.maxTokens.placeholder': 'например, 4096',
   'ai.providers.advancedParams.default': 'По умолчанию у провайдера',
+  'ai.providers.advancedParams.reasoningEffort.help': 'xhigh и max отправляются только если выбранная модель их поддерживает; иначе значение понижается до максимального поддерживаемого уровня.',
 
   // AI Codex
   'ai.codex': 'Codex',
@@ -599,6 +600,10 @@ export const ruAiMessages: Messages = {
   'ai.chatShortcuts.title': 'Быстрые действия чата',
   'ai.chatShortcuts.selectionAction': 'Показывать «Добавить в чат» при выделении в терминале',
   'ai.chatShortcuts.selectionAction.description': 'Показывать небольшую кнопку AI рядом с выделенным текстом терминала.',
+  'ai.chatHistory.title': 'История чата',
+  'ai.chatHistory.messageCap': 'Сообщений, сохраняемых в чате',
+  'ai.chatHistory.messageCap.description': 'Максимальное число сообщений, хранимых для одного чата (50–2000). При уменьшении самые старые сообщения удаляются из хранилища при следующей записи. Большие значения увеличивают объём хранилища и синхронизации с облаком.',
+  'ai.chatHistory.messageCap.unit': 'сообщений',
 
   // AI Error
   'ai.codex.bridgeError': 'Обработчики главного процесса Codex ещё не загружены. Полностью перезапустите Netcatty или dev-процесс Electron и попробуйте снова.',
@@ -654,6 +659,8 @@ export const ruAiMessages: Messages = {
 
   // Unified tooltips for terminal workspace and top tabs (issue #954)
   'terminal.layer.addTerminal': 'Добавить терминал',
+  'terminal.layer.emptyWorkspace': 'В этом рабочем пространстве пока нет терминалов',
+  'terminal.layer.emptyWorkspaceHint': 'Добавьте локальный терминал или подключитесь к хосту, чтобы начать.',
   'terminal.layer.switchToSplitView': 'Переключить в режим разделения',
   'terminal.layer.sftp': 'SFTP',
   'terminal.layer.scripts': 'Скрипты',

application/i18n/locales/ru/core.ts

@@ -1,6 +1,44 @@
 import type { Messages } from '../types';
 
 export const ruCoreMessages: Messages = {
+  "settings.plugins.github.install": "Установить из GitHub",
+  "settings.plugins.github.description": "Загрузите опубликованный выпуск .ncpkg и проверьте источник и разрешения.",
+  "settings.plugins.github.repository": "Репозиторий GitHub",
+  "settings.plugins.github.formats": "Поддерживаются https://github.com/owner/repo, github.com/owner/repo и owner/repo.",
+  "settings.plugins.github.busy": "Загрузка, проверка или установка пакета...",
+  "settings.plugins.github.review": "Источник и целостность пакета не подтверждают доверие к издателю. Скрипты сборки не запускаются. Плагин устанавливается выключенным; проверьте разрешения перед включением.",
+  "settings.plugins.github.accept": "Я доверяю этому репозиторию и проверил заявленные разрешения.",
+  "settings.plugins.github.confirm": "Установить выключенным",
+  "settings.plugins.github.download": "Загрузить и проверить",
+  "settings.plugins.github.error.invalidRepository": "Введите https://github.com/owner/repo, github.com/owner/repo или owner/repo. Укажите только репозиторий, без учётных данных, параметров, фрагментов и дополнительных путей.",
+  "settings.plugins.github.error.unavailable": "Установка плагинов из GitHub недоступна в этом сеансе.",
+  "settings.plugins.github.error.reviewFirst": "Сначала загрузите и проверьте плагин из GitHub.",
+  "settings.plugins.github.error.network": "Не удалось подключиться к GitHub. Проверьте соединение и повторите попытку.",
+  "settings.plugins.github.error.timeout": "Время ожидания загрузки из GitHub истекло. Повторите попытку.",
+  "settings.plugins.github.error.rateLimit": "Достигнут лимит запросов API GitHub. Повторите попытку позже.",
+  "settings.plugins.github.error.notFound": "Репозиторий или файл GitHub не найден. Поддерживаются только доступные публичные репозитории; импортируйте приватные пакеты из локального файла.",
+  "settings.plugins.github.error.accessDenied": "GitHub отказал в доступе. Приватные репозитории и вход в аккаунт не поддерживаются.",
+  "settings.plugins.github.error.http": "Ошибка загрузки из GitHub (HTTP {status}). Повторите попытку позже.",
+  "settings.plugins.github.error.moved": "Репозиторий GitHub перемещён. Введите его текущий адрес.",
+  "settings.plugins.github.error.redirect": "Не удалось проверить перенаправление загрузки GitHub. Загрузите доверенный пакет .ncpkg и импортируйте его из локального файла.",
+  "settings.plugins.github.error.noRelease": "В репозитории нет опубликованного стабильного выпуска. Попросите автора опубликовать выпуск с файлом .ncpkg или импортируйте готовый пакет из локального файла.",
+  "settings.plugins.github.error.noAsset": "В выпуске нет файла .ncpkg. Попросите автора собрать и прикрепить его; Netcatty не собирает репозитории исходного кода.",
+  "settings.plugins.github.error.multipleAssets": "В выпуске несколько файлов .ncpkg. Загрузите нужный пакет и импортируйте его из локального файла.",
+  "settings.plugins.github.error.metadata": "Некорректные метаданные выпуска GitHub. Попросите автора проверить выпуск, тег и файл .ncpkg.",
+  "settings.plugins.github.error.identity": "Пакет не соответствует выбранному репозиторию и выпуску GitHub. Установка остановлена.",
+  "settings.plugins.github.error.commit": "У тега выпуска нет доступного коммита. Попросите автора исправить тег.",
+  "settings.plugins.github.error.size": "Размер пакета GitHub некорректен или превышает лимит загрузки.",
+  "settings.plugins.github.error.integrity": "Загруженный пакет не прошёл проверку размера или SHA-256. Загрузите и проверьте его снова.",
+  "settings.plugins.github.error.package": "GitHub не вернул корректный ZIP-пакет .ncpkg или метаданные выпуска. Попросите автора проверить файл выпуска.",
+  "settings.plugins.github.error.busy": "Операция с плагином GitHub уже выполняется. Закройте предпросмотр и повторите попытку.",
+  "settings.plugins.github.error.expired": "Предпросмотр пакета GitHub устарел. Загрузите и проверьте его снова.",
+  "settings.plugins.github.error.advanced": "Для этого пакета нужен расширенный режим разработчика. Обычный менеджер принимает только браузерные пакеты.",
+  "settings.plugins.github.error.incompatible": "Плагин несовместим с этой версией Netcatty. Уточните технические подробности у автора.",
+  "settings.plugins.github.error.source": "Плагин уже привязан к другому источнику. Перед сменой источника удалите плагин и явно очистите данные прежнего источника.",
+  "settings.plugins.github.error.failed": "Не удалось проверить или установить плагин. Изучите технические подробности перед повторной попыткой.",
+  "settings.plugins.github.error.details": "Технические подробности",
+
+
   // Common
   'common.save': 'Сохранить',
   'common.cancel': 'Отмена',

application/i18n/locales/ru/terminal.ts

@@ -1,6 +1,24 @@
 import type { Messages } from '../types';
 
 export const ruTerminalMessages: Messages = {
+  'terminal.directory.open': 'Текущий каталог: {path}. Сменить каталог',
+  'terminal.directory.unknown': 'Каталог неизвестен',
+  'terminal.directory.search': 'Поиск подкаталогов...',
+  'terminal.directory.directories': 'Каталоги',
+  'terminal.directory.parent': '.. (Родительский каталог)',
+  'terminal.directory.loading': 'Чтение каталогов...',
+  'terminal.directory.empty': 'Нет подкаталогов',
+  'terminal.directory.noMatches': 'Нет подходящих каталогов',
+  'terminal.directory.hidden': 'Показывать скрытые каталоги',
+  'terminal.directory.refresh': 'Обновить',
+  'terminal.directory.unavailable': 'Навигация по каталогам недоступна для этого сеанса.',
+  'terminal.directory.busy': 'Дождитесь пустой командной строки.',
+  'terminal.directory.readFailed': 'Не удалось прочитать каталог. Попробуйте обновить.',
+  'terminal.directory.changeFailed': 'Не удалось подтвердить смену каталога. Обновите перед повтором.',
+  'terminal.directory.unsupportedPath': 'Это имя каталога нельзя безопасно передать в терминал.',
+  'settings.terminal.behavior.contextChips': 'Context Chips',
+  'settings.terminal.behavior.contextChips.desc': 'Показывать панель контекста под быстрыми командами.',
+
   'terminal.toolbar.openSessionLog': 'Открыть журнал сессии',
   'terminal.toolbar.sessionLogActions': 'Действия с журналом',
   'terminal.toolbar.sessionLog.menu': 'Журнал сессии',

application/i18n/locales/ru/vault.ts

@@ -360,7 +360,26 @@ export const ruVaultMessages: Messages = {
   'sftp.extract.extracting': 'Распаковка {fileName}...',
   'sftp.extract.success': 'Распакован {fileName}',
   'sftp.extract.error': 'Не удалось распаковать {fileName}: {error}',
+  'sftp.archive.action': 'Сжать...',
+  'sftp.archive.title': 'Сжать файлы',
+  'sftp.archive.description': 'Создать архив на сервере из выбранных объектов: {count}.',
+  'sftp.archive.name': 'Имя архива',
+  'sftp.archive.format': 'Формат',
+  'sftp.archive.destination': 'Сохранить в',
+  'sftp.archive.create': 'Сжать',
+  'sftp.archive.creating': 'Сжатие...',
+  'sftp.archive.overwriteTitle': 'Заменить существующий архив?',
+  'sftp.archive.overwriteDescription': 'Архив с именем «{name}» уже существует. Подтвердите его замену новым архивом.',
+  'sftp.archive.overwrite': 'Заменить и сжать',
+  'sftp.archive.failed': 'Не удалось создать архив',
+  'sftp.archive.invalidSelection': 'Невозможно сжать выбранные объекты',
+  'sftp.archive.invalidName': 'Введите допустимое имя файла без пути к каталогу.',
+  'sftp.archive.invalidExtension': 'Расширение файла должно соответствовать выбранному формату.',
+  'sftp.archive.connectionChanged': 'Подключение изменилось. Выберите файлы заново.',
+  'sftp.archive.unavailable': 'Создание архивов недоступно для этого подключения.',
+  'sftp.archive.success': 'Создан архив {fileName}',
   'sftp.context.copyToOtherPane': 'Копировать в другую панель',
+  'sftp.context.duplicate': 'Дублировать',
   'sftp.copyToOtherPane.unavailable': 'Откройте двухпанельный режим SFTP и подключите панель назначения перед копированием файлов.',
   'sftp.copyCurrentPath': 'Копировать текущий путь',
   'sftp.copyCurrentPath.success': 'Текущий путь скопирован',

application/i18n/locales/zh-CN/ai.ts

@@ -99,6 +99,7 @@ export const zhCNAiMessages: Messages = {
   'ai.providers.advancedParams.hint': '留空则使用提供商默认值。',
   'ai.providers.advancedParams.maxTokens.placeholder': '例如 4096',
   'ai.providers.advancedParams.default': '提供商默认',
+  'ai.providers.advancedParams.reasoningEffort.help': '仅当所选模型支持时才会发送 xhigh 和 max，否则自动收敛到该模型支持的最高档位。',
 
   // AI Codex
   'ai.codex': 'Codex',
@@ -660,6 +661,10 @@ export const zhCNAiMessages: Messages = {
   'ai.chatShortcuts.title': '聊天快捷入口',
   'ai.chatShortcuts.selectionAction': '选中终端内容时显示“添加到对话”',
   'ai.chatShortcuts.selectionAction.description': '在终端里选中文本后显示 AI 快捷按钮。',
+  'ai.chatHistory.title': '聊天历史',
+  'ai.chatHistory.messageCap': '每个会话保留的消息数',
+  'ai.chatHistory.messageCap.description': '每个会话最多存储的消息条数（50–2000）。调低后会在下一次写入时从存储中丢弃最旧的消息。数值越大，存储占用和云同步体积也越大。',
+  'ai.chatHistory.messageCap.unit': '条消息',
 
   // AI Error
   'ai.codex.bridgeError': 'Codex 主进程处理器尚未加载。请完全重启 Netcatty 或重启 Electron 开发进程，然后重试。',
@@ -715,6 +720,8 @@ export const zhCNAiMessages: Messages = {
 
   // 统一终端工作区和顶部标签的 tooltip 文案 (issue #954)
   'terminal.layer.addTerminal': '添加终端',
+  'terminal.layer.emptyWorkspace': '工作区中还没有终端',
+  'terminal.layer.emptyWorkspaceHint': '添加本地终端或连接主机，开始使用这个工作区。',
   'terminal.layer.switchToSplitView': '切换到分屏视图',
   'terminal.layer.sftp': '文件传输',
   'terminal.layer.scripts': '脚本',

application/i18n/locales/zh-CN/core.ts

@@ -1,6 +1,44 @@
 import type { Messages } from '../types';
 
 export const zhCNCoreMessages: Messages = {
+  "settings.plugins.github.install": "从 GitHub 安装",
+  "settings.plugins.github.description": "下载已发布的 .ncpkg 插件包，安装前请审查来源和所需权限。",
+  "settings.plugins.github.repository": "GitHub 仓库",
+  "settings.plugins.github.formats": "支持 https://github.com/owner/repo、github.com/owner/repo 或 owner/repo。",
+  "settings.plugins.github.busy": "正在下载、验证或安装插件包…",
+  "settings.plugins.github.review": "确认仓库来源并通过完整性校验，并不代表发布者值得信任。安装过程不会运行构建脚本，插件安装后默认禁用。启用前，请确认来源可信并检查各项权限的授权方式。",
+  "settings.plugins.github.accept": "已审查并信任此仓库，且已查看声明的权限。",
+  "settings.plugins.github.confirm": "安装并保持禁用",
+  "settings.plugins.github.download": "下载并审查",
+  "settings.plugins.github.error.invalidRepository": "请输入 https://github.com/owner/repo、github.com/owner/repo 或 owner/repo。请只填写仓库地址，不要包含账号密码、查询参数、片段或额外路径。",
+  "settings.plugins.github.error.unavailable": "当前会话无法从 GitHub 安装插件。",
+  "settings.plugins.github.error.reviewFirst": "请先下载并审查 GitHub 插件。",
+  "settings.plugins.github.error.network": "无法连接 GitHub，请检查网络连接后重试。",
+  "settings.plugins.github.error.timeout": "从 GitHub 下载超时，请重试。",
+  "settings.plugins.github.error.rateLimit": "GitHub API 请求次数已达上限，请稍后重试。",
+  "settings.plugins.github.error.notFound": "未找到 GitHub 仓库或发布附件。仅支持可访问的公开仓库；私有插件包请从本地导入。",
+  "settings.plugins.github.error.accessDenied": "GitHub 拒绝访问。此功能不支持私有仓库或登录验证。",
+  "settings.plugins.github.error.http": "从 GitHub 下载失败（HTTP {status}），请稍后重试。",
+  "settings.plugins.github.error.moved": "此 GitHub 仓库已迁移，请输入当前仓库地址。",
+  "settings.plugins.github.error.redirect": "无法验证 GitHub 下载重定向。请下载可信的 .ncpkg 插件包，再从本地导入。",
+  "settings.plugins.github.error.noRelease": "此仓库尚未发布稳定版本。请作者发布包含 .ncpkg 附件的稳定版本，或从本地导入已构建的插件包。",
+  "settings.plugins.github.error.noAsset": "此版本没有 .ncpkg 附件。请作者构建并上传插件包；Netcatty 无法直接构建源码仓库。",
+  "settings.plugins.github.error.multipleAssets": "此版本包含多个 .ncpkg 附件。请下载需要的插件包，再从本地导入。",
+  "settings.plugins.github.error.metadata": "GitHub 发布信息无效。请作者检查版本发布、标签和 .ncpkg 附件。",
+  "settings.plugins.github.error.identity": "插件包与所选 GitHub 仓库或发布版本不匹配，已停止安装。",
+  "settings.plugins.github.error.commit": "无法访问发布标签对应的提交，请作者修复发布标签。",
+  "settings.plugins.github.error.size": "GitHub 插件包大小无效或超出下载限制。",
+  "settings.plugins.github.error.integrity": "下载的插件包未通过大小或 SHA-256 校验，请重新下载并审查。",
+  "settings.plugins.github.error.package": "GitHub 返回的内容不是有效的 .ncpkg ZIP 插件包或发布信息，请作者检查发布附件。",
+  "settings.plugins.github.error.busy": "已有 GitHub 插件操作正在进行，请关闭预览后重试。",
+  "settings.plugins.github.error.expired": "GitHub 插件包预览已失效，请重新下载并审查。",
+  "settings.plugins.github.error.advanced": "此插件包需要高级开发者模式。普通插件管理仅接受浏览器运行时插件包。",
+  "settings.plugins.github.error.incompatible": "此插件与当前 Netcatty 版本不兼容，请联系作者确认技术详情。",
+  "settings.plugins.github.error.source": "此插件已绑定其他来源。更换来源前，请先卸载插件并明确清除原来源的私有数据。",
+  "settings.plugins.github.error.failed": "无法验证或安装插件，请查看技术详情后再重试。",
+  "settings.plugins.github.error.details": "技术详情",
+
+
   "settings.plugins.landing.checkUpdates": "检查更新",
   "settings.plugins.landing.checkingUpdates": "正在检查…",
   "settings.plugins.landing.updateSummary": "已检查：{checked} · 已发布更新：{updates} · 未检查：{skipped}。",
@@ -1015,7 +1053,26 @@ Vaults 标签保持扁平，不使用这块背景。
   'sftp.extract.extracting': '正在解压 {fileName}...',
   'sftp.extract.success': '已解压 {fileName}',
   'sftp.extract.error': '解压 {fileName} 失败：{error}',
+  'sftp.archive.action': '压缩…',
+  'sftp.archive.title': '压缩文件',
+  'sftp.archive.description': '将 {count} 个选中项目打包到服务器上的压缩包。',
+  'sftp.archive.name': '压缩包名称',
+  'sftp.archive.format': '格式',
+  'sftp.archive.destination': '保存目录',
+  'sftp.archive.create': '压缩',
+  'sftp.archive.creating': '正在压缩…',
+  'sftp.archive.overwriteTitle': '覆盖现有压缩包？',
+  'sftp.archive.overwriteDescription': '“{name}”已存在。确认后将用新的压缩包替换它。',
+  'sftp.archive.overwrite': '覆盖并压缩',
+  'sftp.archive.failed': '压缩失败',
+  'sftp.archive.invalidSelection': '无法压缩此选区',
+  'sftp.archive.invalidName': '请输入有效的文件名，不要包含目录路径。',
+  'sftp.archive.invalidExtension': '文件扩展名必须与所选格式一致。',
+  'sftp.archive.connectionChanged': '连接已切换，请重新选择文件。',
+  'sftp.archive.unavailable': '当前连接不支持创建压缩包。',
+  'sftp.archive.success': '已创建 {fileName}',
   'sftp.context.copyToOtherPane': '复制到另一侧',
+  'sftp.context.duplicate': '创建副本',
   'sftp.copyToOtherPane.unavailable': '请打开双栏 SFTP 文件管理，并连接目标侧后再复制文件。',
   'sftp.copyCurrentPath': '复制当前路径',
   'sftp.copyCurrentPath.success': '已复制当前路径',

application/i18n/locales/zh-CN/terminal.ts

@@ -1,6 +1,24 @@
 import type { Messages } from '../types';
 
 export const zhCNTerminalMessages: Messages = {
+  'terminal.directory.open': '当前目录：{path}。更改目录',
+  'terminal.directory.unknown': '目录未知',
+  'terminal.directory.search': '搜索当前目录下的文件夹…',
+  'terminal.directory.directories': '目录',
+  'terminal.directory.parent': '..（父目录）',
+  'terminal.directory.loading': '正在读取目录…',
+  'terminal.directory.empty': '没有子目录',
+  'terminal.directory.noMatches': '没有匹配的子目录',
+  'terminal.directory.hidden': '显示隐藏目录',
+  'terminal.directory.refresh': '刷新',
+  'terminal.directory.unavailable': '此会话暂不支持目录导航。',
+  'terminal.directory.busy': '请等待终端回到空命令提示符。',
+  'terminal.directory.readFailed': '无法读取此目录，请刷新重试。',
+  'terminal.directory.changeFailed': '未能确认目录切换，请刷新后重试。',
+  'terminal.directory.unsupportedPath': '此目录名称暂不支持快捷切换。',
+  'settings.terminal.behavior.contextChips': 'Context Chips 上下文工具栏',
+  'settings.terminal.behavior.contextChips.desc': '在撰写栏的快捷命令下方显示上下文工具栏。',
+
   'terminal.toolbar.openSessionLog': '打开会话日志',
   'terminal.toolbar.sessionLogActions': '会话日志操作',
   'terminal.toolbar.sessionLog.menu': '会话日志',

application/i18n/locales/zh-TW/ai.ts

@@ -90,6 +90,7 @@ export const zhTWAiMessages: Messages = {
   'ai.providers.advancedParams.hint': '留空則使用供應商預設值。',
   'ai.providers.advancedParams.maxTokens.placeholder': '例如 4096',
   'ai.providers.advancedParams.default': '供應商預設',
+  'ai.providers.advancedParams.reasoningEffort.help': '僅當所選模型支援時才會送出 xhigh 與 max，否則自動收斂到該模型支援的最高檔位。',
 
   // AI Codex
   'ai.codex': 'Codex',
@@ -650,6 +651,10 @@ export const zhTWAiMessages: Messages = {
   'ai.chatShortcuts.title': '聊天快捷入口',
   'ai.chatShortcuts.selectionAction': '選取終端內容時顯示「新增到對話」',
   'ai.chatShortcuts.selectionAction.description': '在終端裡選取文字後顯示 AI 快捷按鈕。',
+  'ai.chatHistory.title': '聊天歷史',
+  'ai.chatHistory.messageCap': '每個會話保留的訊息數',
+  'ai.chatHistory.messageCap.description': '每個會話最多儲存的訊息數（50–2000）。調低後會在下一次寫入時從儲存中捨棄最舊的訊息。數值越大，儲存空間與雲端同步體積也越大。',
+  'ai.chatHistory.messageCap.unit': '則訊息',
 
   // AI Error
   'ai.codex.bridgeError': 'Codex 主程序處理器尚未載入。請完全重新啟動 Netcatty 或重新啟動 Electron 開發程序，然後重試。',
@@ -705,6 +710,8 @@ export const zhTWAiMessages: Messages = {
 
   // 統一終端工作區和頂部標籤的 tooltip 文案 (issue #954)
   'terminal.layer.addTerminal': '新增終端',
+  'terminal.layer.emptyWorkspace': '工作區中還沒有終端',
+  'terminal.layer.emptyWorkspaceHint': '新增本機終端或連線至主機，開始使用這個工作區。',
   'terminal.layer.switchToSplitView': '切換到分割檢視',
   'terminal.layer.sftp': '檔案傳輸',
   'terminal.layer.scripts': '指令碼',

application/i18n/locales/zh-TW/core.ts

@@ -1,6 +1,44 @@
 import type { Messages } from '../types';
 
 export const zhTWCoreMessages: Messages = {
+  "settings.plugins.github.install": "從 GitHub 安裝",
+  "settings.plugins.github.description": "下載已發布的 .ncpkg 外掛套件，安裝前請審查來源與所需權限。",
+  "settings.plugins.github.repository": "GitHub 儲存庫",
+  "settings.plugins.github.formats": "支援 https://github.com/owner/repo、github.com/owner/repo 或 owner/repo。",
+  "settings.plugins.github.busy": "正在下載、驗證或安裝套件…",
+  "settings.plugins.github.review": "確認儲存庫來源並通過完整性驗證，並不代表發布者值得信任。安裝過程不會執行建置腳本，外掛安裝後預設停用。啟用前，請確認來源可信並檢查各項權限的授權方式。",
+  "settings.plugins.github.accept": "已審查並信任此儲存庫，且已查看宣告的權限。",
+  "settings.plugins.github.confirm": "安裝並保持停用",
+  "settings.plugins.github.download": "下載並審查",
+  "settings.plugins.github.error.invalidRepository": "請輸入 https://github.com/owner/repo、github.com/owner/repo 或 owner/repo。請只填寫儲存庫位址，不要包含帳號密碼、查詢參數、片段或額外路徑。",
+  "settings.plugins.github.error.unavailable": "目前的工作階段無法從 GitHub 安裝外掛。",
+  "settings.plugins.github.error.reviewFirst": "請先下載並審查 GitHub 外掛。",
+  "settings.plugins.github.error.network": "無法連線至 GitHub，請檢查網路連線後重試。",
+  "settings.plugins.github.error.timeout": "從 GitHub 下載逾時，請重試。",
+  "settings.plugins.github.error.rateLimit": "GitHub API 請求次數已達上限，請稍後重試。",
+  "settings.plugins.github.error.notFound": "找不到 GitHub 儲存庫或發布附件。僅支援可存取的公開儲存庫；私有外掛套件請從本機匯入。",
+  "settings.plugins.github.error.accessDenied": "GitHub 拒絕存取。此功能不支援私有儲存庫或登入驗證。",
+  "settings.plugins.github.error.http": "從 GitHub 下載失敗（HTTP {status}），請稍後重試。",
+  "settings.plugins.github.error.moved": "此 GitHub 儲存庫已遷移，請輸入目前的儲存庫位址。",
+  "settings.plugins.github.error.redirect": "無法驗證 GitHub 下載重新導向。請下載可信的 .ncpkg 外掛套件，再從本機匯入。",
+  "settings.plugins.github.error.noRelease": "此儲存庫尚未發布穩定版本。請作者發布包含 .ncpkg 附件的穩定版本，或從本機匯入已建置的外掛套件。",
+  "settings.plugins.github.error.noAsset": "此版本沒有 .ncpkg 附件。請作者建置並上傳外掛套件；Netcatty 無法直接建置原始碼儲存庫。",
+  "settings.plugins.github.error.multipleAssets": "此版本包含多個 .ncpkg 附件。請下載需要的外掛套件，再從本機匯入。",
+  "settings.plugins.github.error.metadata": "GitHub 發布資訊無效。請作者檢查版本發布、標籤及 .ncpkg 附件。",
+  "settings.plugins.github.error.identity": "外掛套件與所選 GitHub 儲存庫或發布版本不符，已停止安裝。",
+  "settings.plugins.github.error.commit": "無法存取發布標籤對應的提交，請作者修復發布標籤。",
+  "settings.plugins.github.error.size": "GitHub 外掛套件大小無效或超出下載限制。",
+  "settings.plugins.github.error.integrity": "下載的外掛套件未通過大小或 SHA-256 驗證，請重新下載並審查。",
+  "settings.plugins.github.error.package": "GitHub 傳回的內容不是有效的 .ncpkg ZIP 外掛套件或發布資訊，請作者檢查發布附件。",
+  "settings.plugins.github.error.busy": "已有 GitHub 外掛操作正在進行，請關閉預覽後重試。",
+  "settings.plugins.github.error.expired": "GitHub 外掛套件預覽已失效，請重新下載並審查。",
+  "settings.plugins.github.error.advanced": "此外掛套件需要進階開發者模式。一般外掛管理僅接受瀏覽器執行環境的套件。",
+  "settings.plugins.github.error.incompatible": "此外掛與目前的 Netcatty 版本不相容，請聯絡作者確認技術詳細資料。",
+  "settings.plugins.github.error.source": "此外掛已綁定其他來源。更換來源前，請先解除安裝並明確清除原來源的私有資料。",
+  "settings.plugins.github.error.failed": "無法驗證或安裝外掛，請查看技術詳細資料後再重試。",
+  "settings.plugins.github.error.details": "技術詳細資料",
+
+
   "settings.plugins.landing.checkUpdates": "檢查更新",
   "settings.plugins.landing.checkingUpdates": "正在檢查…",
   "settings.plugins.landing.updateSummary": "已檢查：{checked} · 已發佈更新：{updates} · 未檢查：{skipped}。",
@@ -1017,7 +1055,26 @@ Vaults 分頁維持扁平，不使用這塊背景。
   'sftp.extract.extracting': '正在解壓 {fileName}...',
   'sftp.extract.success': '已解壓 {fileName}',
   'sftp.extract.error': '解壓 {fileName} 失敗：{error}',
+  'sftp.archive.action': '壓縮…',
+  'sftp.archive.title': '壓縮檔案',
+  'sftp.archive.description': '將 {count} 個選取項目打包成伺服器上的壓縮檔。',
+  'sftp.archive.name': '壓縮檔名稱',
+  'sftp.archive.format': '格式',
+  'sftp.archive.destination': '儲存目錄',
+  'sftp.archive.create': '壓縮',
+  'sftp.archive.creating': '正在壓縮…',
+  'sftp.archive.overwriteTitle': '覆寫現有壓縮檔？',
+  'sftp.archive.overwriteDescription': '「{name}」已存在。確認後將以新的壓縮檔取代它。',
+  'sftp.archive.overwrite': '覆寫並壓縮',
+  'sftp.archive.failed': '壓縮失敗',
+  'sftp.archive.invalidSelection': '無法壓縮此選取範圍',
+  'sftp.archive.invalidName': '請輸入有效的檔案名稱，不要包含目錄路徑。',
+  'sftp.archive.invalidExtension': '副檔名必須與所選格式一致。',
+  'sftp.archive.connectionChanged': '連線已切換，請重新選取檔案。',
+  'sftp.archive.unavailable': '目前連線不支援建立壓縮檔。',
+  'sftp.archive.success': '已建立 {fileName}',
   'sftp.context.copyToOtherPane': '複製到另一側',
+  'sftp.context.duplicate': '建立副本',
   'sftp.copyToOtherPane.unavailable': '請開啟雙欄 SFTP 檔案管理，並連線目標側後再複製檔案。',
   'sftp.copyCurrentPath': '複製目前路徑',
   'sftp.copyCurrentPath.success': '已複製目前路徑',

application/i18n/locales/zh-TW/terminal.ts

@@ -1,6 +1,24 @@
 import type { Messages } from '../types';
 
 export const zhTWTerminalMessages: Messages = {
+  'terminal.directory.open': '目前目錄：{path}。變更目錄',
+  'terminal.directory.unknown': '目錄未知',
+  'terminal.directory.search': '搜尋目前目錄下的資料夾…',
+  'terminal.directory.directories': '目錄',
+  'terminal.directory.parent': '..（父目錄）',
+  'terminal.directory.loading': '正在讀取目錄…',
+  'terminal.directory.empty': '沒有子目錄',
+  'terminal.directory.noMatches': '沒有符合的子目錄',
+  'terminal.directory.hidden': '顯示隱藏目錄',
+  'terminal.directory.refresh': '重新整理',
+  'terminal.directory.unavailable': '此工作階段暫不支援目錄導覽。',
+  'terminal.directory.busy': '請等待終端回到空白命令提示字元。',
+  'terminal.directory.readFailed': '無法讀取此目錄，請重新整理後重試。',
+  'terminal.directory.changeFailed': '未能確認目錄切換，請重新整理後重試。',
+  'terminal.directory.unsupportedPath': '此目錄名稱暫不支援快速切換。',
+  'settings.terminal.behavior.contextChips': 'Context Chips 上下文工具列',
+  'settings.terminal.behavior.contextChips.desc': '在撰寫列的快捷命令下方顯示上下文工具列。',
+
   'terminal.toolbar.openSessionLog': '開啟工作階段日誌',
   'terminal.toolbar.sessionLogActions': '工作階段日誌操作',
   'terminal.toolbar.sessionLog.menu': '工作階段日誌',

application/pluginSyncSidecarBridge.ts

@@ -165,7 +165,7 @@ function isSuccessfulApplyResult(result: unknown): boolean {
  * the DB before collection. Ordinary last-known collect snapshots are never
  * re-applied, so local settings edits made after the last collect are kept.
  */
-export async function collectPluginSyncSidecarsFromHost(options?: {
+export async function collectPluginSyncSidecarsFromHost(options: {
   /**
    * When true, never fall back to last-known cache. Returns null if the host is
    * gated off / non-authoritative so callers can omit `pluginSidecars` instead

application/state/aiSessionIdbStorage.test.ts

@@ -0,0 +1,285 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import type { AISession } from '../../infrastructure/ai/types';
+import { installFakeIndexedDb } from './testSupport/fakeIndexedDb';
+import {
+  AI_SESSIONS_META_LAST_WRITE_KEY,
+  AI_SESSIONS_META_MIGRATION_KEY,
+  AI_SESSIONS_META_SCHEMA_VERSION_KEY,
+  idbClearSessions,
+  idbDeleteSessionIds,
+  idbGetAllSessions,
+  idbGetMeta,
+  idbPutMeta,
+  idbPutSession,
+  idbPutSessions,
+  isIndexedDbAvailable,
+  loadOrMigrateAiSessions,
+  mirrorActiveSessionMapToIdb,
+  openAiSessionsIdb,
+  readActiveSessionMapFromIdb,
+  resetAiSessionsIdbForTests,
+} from './aiSessionIdbStorage';
+
+function makeSession(id: string, updatedAt: number): AISession {
+  return {
+    id,
+    title: id,
+    agentId: 'agent',
+    scope: { type: 'terminal', targetId: 't' },
+    messages: [],
+    createdAt: updatedAt,
+    updatedAt,
+  } as AISession;
+}
+
+test('module wrapper roundtrips sessions through the object stores', async () => {
+  const idb = installFakeIndexedDb();
+  try {
+    assert.equal(isIndexedDbAvailable(), true);
+    const db = await openAiSessionsIdb();
+    assert.equal(db.objectStoreNames.contains('sessions'), true);
+    assert.equal(db.objectStoreNames.contains('meta'), true);
+
+    await idbPutSessions(db, [makeSession('chat-a', 2), makeSession('chat-b', 1)]);
+    await idbPutSession(db, { ...makeSession('chat-a', 3), title: 'updated' });
+    const all = await idbGetAllSessions(db);
+    assert.deepEqual(all.map((s) => s.id).sort(), ['chat-a', 'chat-b']);
+    assert.equal(all.find((s) => s.id === 'chat-a')?.title, 'updated');
+
+    await idbDeleteSessionIds(db, ['chat-a']);
+    assert.deepEqual((await idbGetAllSessions(db)).map((s) => s.id), ['chat-b']);
+    await idbClearSessions(db);
+    assert.deepEqual(await idbGetAllSessions(db), []);
+  } finally {
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('meta store roundtrips schema and active-map records', async () => {
+  const idb = installFakeIndexedDb();
+  try {
+    const db = await openAiSessionsIdb();
+    await idbPutMeta(db, AI_SESSIONS_META_SCHEMA_VERSION_KEY, 1);
+    await idbPutMeta(db, AI_SESSIONS_META_LAST_WRITE_KEY, 1234);
+    assert.equal(await idbGetMeta<number>(db, AI_SESSIONS_META_SCHEMA_VERSION_KEY), 1);
+    assert.equal(await idbGetMeta<number>(db, AI_SESSIONS_META_LAST_WRITE_KEY), 1234);
+    assert.equal(await idbGetMeta<number>(db, 'missing'), undefined);
+
+    await mirrorActiveSessionMapToIdb({ 'terminal:t': 'chat-a' });
+    // Mirror uses its own connection.
+    assert.deepEqual(await readActiveSessionMapFromIdb(), { 'terminal:t': 'chat-a' });
+  } finally {
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('loadOrMigrateAiSessions reads IndexedDB first and returns its sessions', async () => {
+  const idb = installFakeIndexedDb();
+  try {
+    const db = await openAiSessionsIdb();
+    await idbPutSessions(db, [makeSession('idb-chat', 1)]);
+    const result = await loadOrMigrateAiSessions(() => JSON.stringify([makeSession('legacy-chat', 2)]));
+    assert.equal(result.source, 'indexeddb');
+    assert.equal(result.idbFailed, false);
+    assert.deepEqual(result.sessions.map((s) => s.id), ['idb-chat']);
+    // Legacy key content was not consumed for a migration when IDB has data.
+    assert.equal(idb.db.dumpStore('sessions').length, 1);
+  } finally {
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('loadOrMigrateAiSessions migrates a populated legacy store into empty IndexedDB, keeping the key untouched', async () => {
+  const idb = installFakeIndexedDb();
+  try {
+    const legacyRaw = JSON.stringify([makeSession('legacy-1', 2), makeSession('legacy-2', 1)]);
+    let readCount = 0;
+    const result = await loadOrMigrateAiSessions(() => {
+      readCount += 1;
+      return legacyRaw;
+    });
+    assert.equal(result.source, 'legacy-localstorage');
+    assert.equal(result.idbFailed, false);
+    assert.deepEqual(result.sessions.map((s) => s.id).sort(), ['legacy-1', 'legacy-2']);
+    // Now in IndexedDB (one record per session).
+    assert.deepEqual(
+      idb.db.dumpStore('sessions').map((s) => (s as AISession).id).sort(),
+      ['legacy-1', 'legacy-2'],
+    );
+    // Meta records written for the migration.
+    const db = await openAiSessionsIdb();
+    assert.equal(await idbGetMeta<number>(db, AI_SESSIONS_META_SCHEMA_VERSION_KEY), 1);
+    assert.ok(await idbGetMeta<number>(db, AI_SESSIONS_META_LAST_WRITE_KEY));
+    assert.ok(readCount >= 1);
+    // The legacy raw string itself is only read, never rewritten or removed
+    // — the callback is the only interface to the legacy store.
+    assert.equal(readCount >= 1, true);
+  } finally {
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('loadOrMigrateAiSessions returns none for an empty store without legacy data', async () => {
+  const idb = installFakeIndexedDb();
+  try {
+    const result = await loadOrMigrateAiSessions(() => null);
+    assert.equal(result.source, 'none');
+    assert.deepEqual(result.sessions, []);
+    assert.equal(result.idbFailed, false);
+    assert.equal(result.authoritativeEmpty, false, 'a newly created store still permits disk recovery');
+    assert.equal(result.migrationPending, false);
+  } finally {
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('loadOrMigrateAiSessions treats a legacy empty array as an intentional wipe (no migration, no restore source)', async () => {
+  const idb = installFakeIndexedDb();
+  try {
+    const result = await loadOrMigrateAiSessions(() => '[]');
+    assert.equal(result.source, 'none');
+    assert.deepEqual(result.sessions, []);
+    assert.equal(idb.db.dumpStore('sessions').length, 0);
+  } finally {
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('loadOrMigrateAiSessions falls back to legacy localStorage when IndexedDB is corrupt', async () => {
+  const idb = installFakeIndexedDb({ failOpen: true });
+  try {
+    const legacy = [makeSession('legacy-chat', 1)];
+    const result = await loadOrMigrateAiSessions(() => JSON.stringify(legacy));
+    assert.equal(result.source, 'legacy-localstorage');
+    assert.equal(result.idbFailed, true);
+    assert.deepEqual(result.sessions, legacy);
+  } finally {
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('loadOrMigrateAiSessions falls back to legacy localStorage when IndexedDB is unavailable', async () => {
+  const previous = (globalThis as { indexedDB?: unknown }).indexedDB;
+  (globalThis as { indexedDB?: unknown }).indexedDB = undefined;
+  try {
+    const legacy = [makeSession('legacy-chat', 1)];
+    const result = await loadOrMigrateAiSessions(() => JSON.stringify(legacy));
+    assert.equal(isIndexedDbAvailable(), false);
+    assert.equal(result.source, 'legacy-localstorage');
+    assert.equal(result.idbFailed, false);
+    assert.deepEqual(result.sessions, legacy);
+  } finally {
+    (globalThis as { indexedDB?: unknown }).indexedDB = previous;
+    resetAiSessionsIdbForTests();
+  }
+});
+
+// ── Issue #4125 review P1②: the migration is one-shot via a persisted marker ──
+
+test('a completed migration is one-shot: a chat deleted afterwards stays deleted on the next boot', async () => {
+  const idb = installFakeIndexedDb();
+  try {
+    const legacyRaw = JSON.stringify([makeSession('legacy-1', 2), makeSession('legacy-2', 1)]);
+    const first = await loadOrMigrateAiSessions(() => legacyRaw);
+    assert.equal(first.source, 'legacy-localstorage');
+    // The marker was persisted after the migration data became durable.
+    let db = await openAiSessionsIdb();
+    assert.ok(await idbGetMeta(db, AI_SESSIONS_META_MIGRATION_KEY));
+    // The user deletes a chat; the legacy key stays behind by design.
+    await idbDeleteSessionIds(db, ['legacy-1']);
+    // Next boot: the marker is present, so the legacy key is never
+    // re-migrated and the deletion is not resurrected.
+    const second = await loadOrMigrateAiSessions(() => legacyRaw);
+    assert.equal(second.source, 'indexeddb');
+    assert.deepEqual(second.sessions.map((s) => s.id), ['legacy-2']);
+    assert.equal((await openAiSessionsIdb()).objectStoreNames.contains('sessions'), true);
+    db = await openAiSessionsIdb();
+    assert.deepEqual((await idbGetAllSessions(db)).map((s) => s.id), ['legacy-2']);
+  } finally {
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('an empty IndexedDB store with the migration marker ignores a populated legacy key', async () => {
+  const idb = installFakeIndexedDb();
+  try {
+    // First boot with nothing anywhere records the marker.
+    const first = await loadOrMigrateAiSessions(() => null);
+    assert.equal(first.source, 'none');
+    assert.ok(await idbGetMeta(await openAiSessionsIdb(), AI_SESSIONS_META_MIGRATION_KEY));
+    // The user deleted every chat, but the stale legacy key is still there.
+    const second = await loadOrMigrateAiSessions(
+      () => JSON.stringify([makeSession('resurrected', 1)]),
+    );
+    assert.equal(second.source, 'none');
+    assert.equal(second.authoritativeEmpty, true);
+    assert.deepEqual(second.sessions, []);
+    assert.equal(idb.db.dumpStore('sessions').length, 0);
+  } finally {
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('partial disk migration retries missing IDs beside existing IDB records until all are durable', async () => {
+  const idb = installFakeIndexedDb();
+  try {
+    const primary = makeSession('primary', 3);
+    const diskA = makeSession('disk-a', 2);
+    const diskB = makeSession('disk-b', 1);
+    const diskIds = [diskA.id, diskB.id];
+    const db = await openAiSessionsIdb();
+    const first = await loadOrMigrateAiSessions(() => JSON.stringify([primary]), diskIds);
+    assert.equal(first.migrationPending, true);
+    assert.deepEqual(await idbGetAllSessions(db), [primary]);
+    assert.equal(await idbGetMeta(db, AI_SESSIONS_META_MIGRATION_KEY), undefined);
+
+    const updated = { ...primary, title: 'edited in IndexedDB', updatedAt: 4 };
+    await idbPutSession(db, updated);
+    const partial = await loadOrMigrateAiSessions(() => JSON.stringify([primary, diskA]), diskIds);
+    assert.equal(partial.migrationPending, true, 'one recovered disk ID does not complete migration');
+    assert.deepEqual(partial.sessions, [updated, diskA]);
+    assert.equal(await idbGetMeta(db, AI_SESSIONS_META_MIGRATION_KEY), undefined);
+
+    const complete = await loadOrMigrateAiSessions(() => JSON.stringify([primary, diskA, diskB]), diskIds);
+    assert.equal(complete.source, 'indexeddb');
+    assert.equal(complete.migrationPending, false);
+    assert.deepEqual(complete.sessions, [updated, diskA, diskB]);
+    assert.deepEqual(await idbGetAllSessions(db), [updated, diskA, diskB]);
+    assert.ok(await idbGetMeta(db, AI_SESSIONS_META_MIGRATION_KEY));
+
+    await idbClearSessions(db);
+    const deleted = await loadOrMigrateAiSessions(() => {
+      assert.fail('completed migration must not retry the stale overflow markers');
+    }, diskIds);
+    assert.equal(deleted.authoritativeEmpty, true);
+    assert.deepEqual(deleted.sessions, []);
+  } finally {
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('a pre-marker store that already holds sessions records the marker on boot', async () => {
+  const idb = installFakeIndexedDb();
+  try {
+    const db = await openAiSessionsIdb();
+    await idbPutSessions(db, [makeSession('already-here', 1)]);
+    const result = await loadOrMigrateAiSessions(() => JSON.stringify([makeSession('legacy', 2)]));
+    assert.equal(result.source, 'indexeddb');
+    assert.ok(await idbGetMeta(db, AI_SESSIONS_META_MIGRATION_KEY));
+    assert.equal(idb.db.dumpStore('sessions').length, 1);
+  } finally {
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});

application/state/aiSessionIdbStorage.ts

@@ -0,0 +1,372 @@
+import type { AISession } from '../../infrastructure/ai/types';
+
+/**
+ * IndexedDB persistence for AI chat sessions (issue #4123).
+ *
+ * The legacy store kept every session as one JSON blob in localStorage under
+ * a 2 MB byte budget. Each write re-serialized the whole store, and when the
+ * budget was exceeded the degradation ladder dropped whole oldest sessions —
+ * silently destroying capped chats (~1 MB each) on every write.
+ *
+ * IndexedDB removes both halves of that failure mode: records are written
+ * per session (no global re-serialization), and there is no shared byte
+ * quota to defend, so byte-driven eviction disappears entirely.
+ *
+ * Layout:
+ * - db `netcatty_ai_sessions`
+ *   - object store `sessions` (keyPath `id`): one record per AISession
+ *   - object store `meta` (keyPath `key`): schemaVersion, lastWriteAt and the
+ *     migrated `netcatty_ai_active_session_map_v1` active-pointer map
+ *
+ * The legacy localStorage key `netcatty_ai_sessions_v1` is kept UNTOUCHED for
+ * one release as a read-only fallback; it is no longer written or pruned.
+ */
+
+export const AI_SESSIONS_IDB_NAME = 'netcatty_ai_sessions';
+export const AI_SESSIONS_IDB_VERSION = 1;
+export const AI_SESSIONS_IDB_SESSION_STORE = 'sessions';
+export const AI_SESSIONS_IDB_META_STORE = 'meta';
+export const AI_SESSIONS_META_SCHEMA_VERSION_KEY = 'schemaVersion';
+export const AI_SESSIONS_META_LAST_WRITE_KEY = 'lastWriteAt';
+export const AI_SESSIONS_META_ACTIVE_MAP_KEY = 'activeSessionMap';
+export const AI_SESSIONS_META_MIGRATION_KEY = 'migrationCompleted';
+
+/** Cross-window change notification (replaces the localStorage `storage` event for sessions). */
+const AI_SESSIONS_IDB_CHANGE_CHANNEL = 'netcatty_ai_sessions_changed';
+
+export function isIndexedDbAvailable(): boolean {
+  return typeof indexedDB !== 'undefined' && indexedDB !== null;
+}
+
+function requestToPromise<T>(request: IDBRequest<T>): Promise<T> {
+  return new Promise((resolve, reject) => {
+    request.onsuccess = () => resolve(request.result);
+    request.onerror = () => reject(request.error ?? new Error('IndexedDB request failed'));
+  });
+}
+
+function transactionDone(transaction: IDBTransaction): Promise<void> {
+  return new Promise((resolve, reject) => {
+    transaction.oncomplete = () => resolve();
+    transaction.onabort = () => reject(transaction.error ?? new Error('IndexedDB transaction aborted'));
+    transaction.onerror = () => reject(transaction.error ?? new Error('IndexedDB transaction failed'));
+  });
+}
+
+let openPromise: Promise<IDBDatabase> | null = null;
+
+function upgradeDatabase(db: IDBDatabase) {
+  if (!db.objectStoreNames.contains(AI_SESSIONS_IDB_SESSION_STORE)) {
+    db.createObjectStore(AI_SESSIONS_IDB_SESSION_STORE, { keyPath: 'id' });
+  }
+  if (!db.objectStoreNames.contains(AI_SESSIONS_IDB_META_STORE)) {
+    db.createObjectStore(AI_SESSIONS_IDB_META_STORE, { keyPath: 'key' });
+  }
+}
+
+export function openAiSessionsIdb(): Promise<IDBDatabase> {
+  if (!isIndexedDbAvailable()) {
+    return Promise.reject(new Error('IndexedDB is not available'));
+  }
+  if (!openPromise) {
+    openPromise = new Promise((resolve, reject) => {
+      const request = indexedDB.open(AI_SESSIONS_IDB_NAME, AI_SESSIONS_IDB_VERSION);
+      request.onupgradeneeded = () => upgradeDatabase(request.result);
+      request.onsuccess = () => {
+        const db = request.result;
+        // Drop the cached handle so a later open() re-establishes it instead
+        // of handing out a closed connection.
+        db.onclose = () => { openPromise = null; };
+        db.onversionchange = () => {
+          db.close();
+          openPromise = null;
+        };
+        resolve(db);
+      };
+      request.onerror = () => {
+        openPromise = null;
+        reject(request.error ?? new Error('Failed to open IndexedDB'));
+      };
+      request.onblocked = () => {
+        openPromise = null;
+      };
+    });
+  }
+  return openPromise;
+}
+
+export function resetAiSessionsIdbForTests() {
+  openPromise = null;
+}
+
+export async function idbGetAllSessions(db?: IDBDatabase): Promise<AISession[]> {
+  const database = db ?? await openAiSessionsIdb();
+  const transaction = database.transaction(AI_SESSIONS_IDB_SESSION_STORE, 'readonly');
+  const result = await requestToPromise(
+    transaction.objectStore(AI_SESSIONS_IDB_SESSION_STORE).getAll() as IDBRequest<AISession[]>,
+  );
+  return Array.isArray(result) ? result : [];
+}
+
+export async function idbPutSessions(db: IDBDatabase, sessions: AISession[]): Promise<void> {
+  if (sessions.length === 0) return;
+  const transaction = db.transaction(AI_SESSIONS_IDB_SESSION_STORE, 'readwrite');
+  const store = transaction.objectStore(AI_SESSIONS_IDB_SESSION_STORE);
+  for (const session of sessions) store.put(session);
+  await transactionDone(transaction);
+}
+
+export async function idbPutSession(db: IDBDatabase, session: AISession): Promise<void> {
+  await idbPutSessions(db, [session]);
+}
+
+export async function idbDeleteSessionIds(db: IDBDatabase, ids: string[]): Promise<void> {
+  if (ids.length === 0) return;
+  const transaction = db.transaction(AI_SESSIONS_IDB_SESSION_STORE, 'readwrite');
+  const store = transaction.objectStore(AI_SESSIONS_IDB_SESSION_STORE);
+  for (const id of ids) store.delete(id);
+  await transactionDone(transaction);
+}
+
+export async function idbClearSessions(db: IDBDatabase): Promise<void> {
+  const transaction = db.transaction(AI_SESSIONS_IDB_SESSION_STORE, 'readwrite');
+  transaction.objectStore(AI_SESSIONS_IDB_SESSION_STORE).clear();
+  await transactionDone(transaction);
+}
+
+export async function idbGetMeta<T>(db: IDBDatabase, key: string): Promise<T | undefined> {
+  const transaction = db.transaction(AI_SESSIONS_IDB_META_STORE, 'readonly');
+  const record = await requestToPromise(
+    transaction.objectStore(AI_SESSIONS_IDB_META_STORE).get(key) as IDBRequest<{ key: string; value: T } | undefined>,
+  );
+  return record?.value;
+}
+
+export async function idbPutMeta<T>(db: IDBDatabase, key: string, value: T): Promise<void> {
+  const transaction = db.transaction(AI_SESSIONS_IDB_META_STORE, 'readwrite');
+  transaction.objectStore(AI_SESSIONS_IDB_META_STORE).put({ key, value });
+  await transactionDone(transaction);
+}
+
+// ── Cross-window change notification ──
+
+let changeChannel: BroadcastChannel | null = null;
+
+function getChangeChannel(): BroadcastChannel | null {
+  if (typeof BroadcastChannel === 'undefined') return null;
+  try {
+    if (!changeChannel) {
+      changeChannel = new BroadcastChannel(AI_SESSIONS_IDB_CHANGE_CHANNEL);
+      // The channel must never keep the process alive (Node exposes unref).
+      (changeChannel as unknown as { unref?: () => void }).unref?.();
+    }
+    return changeChannel;
+  } catch {
+    return null;
+  }
+}
+
+/** Announce a session-store change to OTHER windows (never the sender). */
+export function publishAiSessionsIdbChange(): void {
+  try {
+    getChangeChannel()?.postMessage(Date.now());
+  } catch {
+    // Notification is best-effort; the write itself already succeeded.
+  }
+}
+
+export function subscribeAiSessionsIdbChange(listener: () => void): () => void {
+  const channel = getChangeChannel();
+  if (!channel) return () => {};
+  const handler = () => listener();
+  channel.addEventListener('message', handler);
+  return () => channel.removeEventListener('message', handler);
+}
+
+// ── Boot load + one-release legacy migration ──
+
+export interface AiSessionsBootLoadResult {
+  sessions: AISession[];
+  /** Where the returned sessions came from. */
+  source: 'indexeddb' | 'legacy-localstorage' | 'none';
+  /** True when IndexedDB itself could not be opened (corrupt/blocked). */
+  idbFailed: boolean;
+  /** The store was already initialized before this boot; empty means deleted. */
+  authoritativeEmpty: boolean;
+  /** Marked disk-only records are still missing; keep their backup generations. */
+  migrationPending: boolean;
+}
+
+/**
+ * Boot-time store resolution, shared with tests:
+ * 1. IndexedDB `getAll()` — the primary store.
+ * 2. If empty, migrate the legacy localStorage store into IndexedDB (the
+ *    legacy key itself stays untouched as a read-only fallback for one
+ *    release).
+ * 3. If IndexedDB is corrupt/unavailable, fall back to legacy localStorage.
+ *
+ * The migration is one-shot (issue #4125 review P1②): a `migrationCompleted`
+ * marker is persisted in the meta store after the first successful boot
+ * resolution. Once present, the legacy key is never consulted again —
+ * otherwise a boot whose migration ran while the legacy key could not be
+ * removed would re-migrate the stale legacy list and resurrect deleted
+ * chats. The marker also distinguishes "intentionally empty" (the user
+ * deleted every chat) from "uninitialized".
+ *
+ * Callers decide what to do when both sources are empty (the #4018 backup
+ * generations remain the last restore step in useAIState).
+ * The legacy reader may await disk-only recovery before migration completes.
+ * Missing disk-only IDs keep migration resumable, including in a populated IDB.
+ */
+export async function loadOrMigrateAiSessions(
+  readLegacyRaw: () => string | null | undefined | Promise<string | null | undefined>,
+  diskOnlySessionIds: readonly string[] = [],
+): Promise<AiSessionsBootLoadResult> {
+  const hasUnresolvedDiskSessions = (sessions: AISession[]) => {
+    const ids = new Set(sessions.map(session => session.id));
+    return diskOnlySessionIds.some(id => !ids.has(id));
+  };
+  const legacyFallback = async (idbFailed: boolean): Promise<AiSessionsBootLoadResult> => {
+    const legacy = parseLegacySessions(await readLegacyRaw());
+    return {
+      sessions: legacy,
+      source: legacy.length > 0 ? 'legacy-localstorage' : 'none',
+      idbFailed,
+      authoritativeEmpty: false,
+      migrationPending: hasUnresolvedDiskSessions(legacy),
+    };
+  };
+  if (!isIndexedDbAvailable()) {
+    return legacyFallback(false);
+  }
+  let db: IDBDatabase;
+  try {
+    db = await openAiSessionsIdb();
+  } catch (error) {
+    console.warn('[AIState] IndexedDB unavailable, falling back to the legacy localStorage store:', error);
+    return legacyFallback(true);
+  }
+  let sessions: AISession[];
+  try {
+    sessions = await idbGetAllSessions(db);
+  } catch (error) {
+    console.warn('[AIState] IndexedDB read failed, falling back to the legacy localStorage store:', error);
+    return legacyFallback(true);
+  }
+  let marker: AiSessionsMigrationMarker | undefined;
+  try {
+    marker = await idbGetMeta<AiSessionsMigrationMarker>(db, AI_SESSIONS_META_MIGRATION_KEY);
+  } catch {
+    marker = undefined;
+  }
+  if (marker || (sessions.length > 0 && !hasUnresolvedDiskSessions(sessions))) {
+    if (!marker) {
+      // First boot on a store that already holds sessions (e.g. migrated by
+      // a build without the marker): record one-shot completion so the
+      // legacy key can never re-seed the store.
+      await writeMigrationMarker(db).catch(() => {});
+    }
+    return {
+      sessions,
+      source: sessions.length > 0 ? 'indexeddb' : 'none',
+      idbFailed: false,
+      authoritativeEmpty: sessions.length === 0,
+      migrationPending: false,
+    };
+  }
+  // Unfinished migration (empty or partially populated IDB). The legacy key is
+  // intentionally NOT removed: it stays as a read-only fallback for one
+  // release.
+  const legacy = parseLegacySessions(await readLegacyRaw());
+  // A partial migration may already have primary/chunk records in IDB. Only
+  // fill missing marked IDs; never replay stale primary data over live IDB.
+  const existingIds = new Set(sessions.map(session => session.id));
+  const diskOnlyIds = new Set(diskOnlySessionIds);
+  const recovered = sessions.length === 0
+    ? legacy
+    : legacy.filter(session => diskOnlyIds.has(session.id) && !existingIds.has(session.id));
+  const merged = [...sessions, ...recovered].sort((a, b) => (b.updatedAt ?? 0) - (a.updatedAt ?? 0));
+  const migrationPending = hasUnresolvedDiskSessions(merged);
+  const result: AiSessionsBootLoadResult = {
+    sessions: merged,
+    source: sessions.length > 0 ? 'indexeddb' : merged.length > 0 ? 'legacy-localstorage' : 'none',
+    idbFailed: false,
+    authoritativeEmpty: false,
+    migrationPending,
+  };
+  if (merged.length === 0) {
+    // Nothing to migrate: mark the store initialized so this state is
+    // distinguishable from "uninitialized" on the next boot.
+    if (!migrationPending) await writeMigrationMarker(db).catch(() => {});
+    return result;
+  }
+  try {
+    await idbPutSessions(db, recovered);
+    await idbPutMeta(db, AI_SESSIONS_META_SCHEMA_VERSION_KEY, AI_SESSIONS_IDB_VERSION);
+    await idbPutMeta(db, AI_SESSIONS_META_LAST_WRITE_KEY, Date.now());
+    // Written AFTER the migration data is durable: a crash before this point
+    // leaves the marker absent and the next boot safely re-migrates.
+    if (!migrationPending) await writeMigrationMarker(db);
+  } catch (error) {
+    console.warn('[AIState] IndexedDB migration write failed; keeping legacy store authoritative:', error);
+    return { ...result, idbFailed: true };
+  }
+  console.info(`[AIState] Migrated ${recovered.length} AI session(s) from localStorage to IndexedDB.`);
+  return result;
+}
+
+interface AiSessionsMigrationMarker {
+  migrationCompleted: true;
+  migrationAt: number;
+}
+
+async function writeMigrationMarker(db: IDBDatabase): Promise<void> {
+  await idbPutMeta<AiSessionsMigrationMarker>(
+    db,
+    AI_SESSIONS_META_MIGRATION_KEY,
+    { migrationCompleted: true, migrationAt: Date.now() },
+  );
+}
+
+function parseLegacySessions(raw: string | null | undefined): AISession[] {
+  if (raw == null || raw === '') return [];
+  try {
+    const parsed: unknown = JSON.parse(raw);
+    return Array.isArray(parsed) ? parsed as AISession[] : [];
+  } catch {
+    return [];
+  }
+}
+
+// ── Active-session map mirror (meta store) ──
+
+/**
+ * Mirror the active-pointer map into the IndexedDB meta store. The
+ * localStorage key remains written as before (small, quota-safe) and stays
+ * the read-mostly authority for this release; the mirror makes the pointer
+ * available to future store work without another migration.
+ */
+export async function mirrorActiveSessionMapToIdb(
+  map: Record<string, string | null>,
+): Promise<void> {
+  try {
+    const db = await openAiSessionsIdb();
+    await idbPutMeta(db, AI_SESSIONS_META_ACTIVE_MAP_KEY, map);
+  } catch (error) {
+    console.warn('[AIState] Failed to mirror the active-session map to IndexedDB:', error);
+  }
+}
+
+/**
+ * Read the mirrored active-pointer map (boot restore aid when the
+ * localStorage key is missing).
+ */
+export async function readActiveSessionMapFromIdb(): Promise<Record<string, string | null> | null> {
+  try {
+    const db = await openAiSessionsIdb();
+    const value = await idbGetMeta<Record<string, string | null>>(db, AI_SESSIONS_META_ACTIVE_MAP_KEY);
+    return value && typeof value === 'object' ? value : null;
+  } catch {
+    return null;
+  }
+}

application/state/aiSessionsBackup.test.ts

@@ -66,10 +66,12 @@ test('parseBackupSessions ignores corrupt payloads and drops malformed entries',
 });
 
 test('restore preserves all sessions when cloud sync is enabled', () => {
-  const sessions = Array.from({ length: 51 }, (_, index) => makeSession(`s${index}`, index));
+  // Issue #4123: the retention cap is a session count (raised to 1000) —
+  // there is no byte budget any more.
+  const sessions = Array.from({ length: 1001 }, (_, index) => makeSession(`s${index}`, index));
   assert.deepEqual(prepareRestoredSessions(sessions, true), sessions);
   const local = prepareRestoredSessions(sessions, false);
-  assert.equal(local.length, 50);
+  assert.equal(local.length, 1000);
   assert.equal(local.some(session => session.id === 's0'), false);
 });
 

application/state/aiStateSnapshots.ts

@@ -2,10 +2,13 @@ import { localStorageAdapter } from '../../infrastructure/persistence/localStora
 import {
   STORAGE_KEY_AI_ACTIVE_SESSION_MAP,
   STORAGE_KEY_AI_SESSIONS,
-  STORAGE_KEY_AI_SESSIONS_OVERFLOW,
-  STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW,
+  STORAGE_KEY_AI_SESSION_MESSAGE_CAP,
   STORAGE_KEY_CLOUD_SYNC_AI_SESSIONS,
 } from '../../infrastructure/config/storageKeys';
+import {
+  DEFAULT_AI_SESSION_MESSAGE_CAP,
+  normalizeAiSessionMessageCap,
+} from '../../domain/aiSessionMessageCap';
 import type {
   AIDraft,
   AIPanelView,
@@ -13,7 +16,6 @@ import type {
   AIPermissionMode,
   AIToolIntegrationMode,
 } from '../../infrastructure/ai/types';
-import type { ProviderContinuationOptions } from '../../infrastructure/ai/providerContinuation';
 import { findSafeChatMessageCompactionSplitIndex } from '../../infrastructure/ai/contextCompaction';
 import {
   bumpDraftMutationVersionState,
@@ -27,7 +29,16 @@ import {
 import { emitAIStateChanged } from './aiStateEvents';
 import { peekAgentRuntimeCleanup } from '../../infrastructure/ai/harness/agentRuntimeHandle';
 import { setReversibleModelPrivacy } from '../../infrastructure/ai/harness/modelSecretRedaction';
-import { DebouncedBackupMirror, mergeImportedSessions, readLiveSessionsArray } from './aiSessionsBackup';
+import { DebouncedBackupMirror, readLiveSessionsArray } from './aiSessionsBackup';
+import {
+  idbDeleteSessionIds,
+  idbPutMeta,
+  idbPutSessions,
+  isIndexedDbAvailable,
+  openAiSessionsIdb,
+  publishAiSessionsIdbChange,
+  resetAiSessionsIdbForTests,
+} from './aiSessionIdbStorage';
 
 /** Typed accessor for the Electron IPC bridge exposed on `window.netcatty`. */
 export interface AIBridge {
@@ -64,6 +75,13 @@ export async function cleanupSdkAgentSessions(sessionIds: string[]): Promise<voi
   await Promise.all(sessionIds.map((sessionId) => bridge?.aiSdkAgentCleanup?.(sessionId).catch(() => {})));
 }
 
+/**
+ * Session ids explicitly deleted by the user (or by an authoritative cloud
+ * merge). Their disappearance from the persisted set must not trigger the
+ * pre-eviction backup generation — only cap-driven drops should.
+ */
+const intentionallyDeletedSessionIds = new Set<string>();
+
 export function cleanupDeletedAIChatSessions(sessionIds: string[]) {
   const bridge = getAIBridge();
   if (sessionIds.length === 0) return;
@@ -73,6 +91,7 @@ export function cleanupDeletedAIChatSessions(sessionIds: string[]) {
   // main-process privacy mapping may still exist, so always clear those.
   const runtime = peekAgentRuntimeCleanup();
   for (const sessionId of sessionIds) {
+    intentionallyDeletedSessionIds.add(sessionId);
     if (runtime) {
       runtime.clearChatSession(sessionId);
     } else {
@@ -108,8 +127,11 @@ export let latestAIActiveTargetIdsSnapshot: Set<string> = new Set();
 
 export function cleanupOrphanedAISessions(activeTargetIds: Set<string>) {
   latestAIActiveTargetIdsSnapshot = activeTargetIds;
-  const currentSessions = latestAISessionsSnapshot
-    ?? readSessionsFromStorage();
+  // Child maintenance effects run before the provider's boot effects. Keep
+  // the live targets for post-hydration cleanup without adopting stale legacy
+  // history as authoritative state while IndexedDB is still loading.
+  if (!isAiSessionsHydrationComplete()) return;
+  const currentSessions = latestAISessionsSnapshot ?? getPersistedAiSessionsSnapshot();
 
   // Sessions shown by a still-live scope must be protected from cleanup
   // even when their own `scope.targetId` points at a closed terminal —
@@ -160,14 +182,7 @@ export function cleanupOrphanedAISessions(activeTargetIds: Set<string>) {
 
   if (sessionsMarked) {
     setLatestAISessionsSnapshot(markedSessions);
-    // Startup cleanup can run before the disk backup read resolves. Defer
-    // persistence until those chats are merged, preserving their recovery
-    // marker and avoiding a partial backup of only the loaded sessions.
-    const diskOnlyIds = localStorageAdapter.read<string[]>(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW) ?? [];
-    const loadedIds = new Set(markedSessions.map(session => session.id));
-    if (!diskOnlyIds.some(id => !loadedIds.has(id))) {
-      writeSessionsForStorage(markedSessions);
-    }
+    writeSessionsForStorage(markedSessions);
     emitAIStateChanged(STORAGE_KEY_AI_SESSIONS);
   }
 
@@ -203,159 +218,53 @@ export function cleanupOrphanedAISessions(activeTargetIds: Set<string>) {
 }
 
 
-/** Maximum number of sessions to keep in localStorage. */
-const MAX_STORED_SESSIONS = 50;
-/** Maximum number of messages per session when persisting to localStorage. */
-const MAX_SESSION_MESSAGES = 200;
 /**
- * String-length budget for the primary sessions JSON and each overflow chunk.
- * Replay bulk is shed from the primary blob first; whole sessions that still
- * do not fit are retained in overflow rather than silently evicted.
+ * Maximum number of sessions kept in the persisted store. IndexedDB has no
+ * shared byte quota, so retention is a plain count cap; the cap only exists
+ * to keep history from growing without bound.
  */
-const MAX_SESSIONS_JSON_BYTES = 2 * 1024 * 1024;
-/** Retry budgets used when the primary budget still fails to persist. */
-const RETRY_SESSIONS_JSON_BYTES = [
-  1024 * 1024,
-  512 * 1024,
-  256 * 1024,
-  128 * 1024,
-] as const;
+const MAX_STORED_SESSIONS = 1000;
 
 /**
- * Maximum persisted length of a single tool result payload. Terminal tool
- * output can reach hundreds of KB per command, and AI-driven terminal work
- * accumulates many of them. When storage pressure forces degradation, shedding
- * this replay bulk keeps every visible conversation persisted instead of
- * evicting whole chats that happen to carry it.
+ * Per-session message cap, read from user settings (clamped to 50–2000,
+ * default 200). Read on every write so a lowered cap trims the oldest
+ * messages on the next write; a raised cap stops further trimming.
+ * Best-effort: an unavailable storage layer keeps the default cap.
  */
-const MAX_PERSISTED_TOOL_RESULT_CHARS = 8 * 1024;
-
-function truncatePersistedToolResultContent(content: string): string {
-  if (content.length <= MAX_PERSISTED_TOOL_RESULT_CHARS) return content;
-  // The marker consumes budget and must stay single-line: JSON-escaped
-  // newlines would cost 2 characters each, letting a slightly-over-cap
-  // result serialize at the same (or larger) size than the original — the
-  // ladder assumes the degraded form is the smallest. Shrink the retained
-  // head+tail until the whole persisted copy fits the cap.
-  let half = Math.floor(MAX_PERSISTED_TOOL_RESULT_CHARS / 2);
-  let omitted = content.length - 2 * half;
-  let marker = `[Netcatty] persisted copy truncated; ${omitted} characters of tool output omitted`;
-  while (2 * half + marker.length > MAX_PERSISTED_TOOL_RESULT_CHARS) {
-    half -= Math.ceil((2 * half + marker.length - MAX_PERSISTED_TOOL_RESULT_CHARS) / 2);
-    omitted = content.length - 2 * half;
-    marker = `[Netcatty] persisted copy truncated; ${omitted} characters of tool output omitted`;
+export function readAiSessionMessageCap(): number {
+  try {
+    return normalizeAiSessionMessageCap(
+      localStorageAdapter.readNumber(STORAGE_KEY_AI_SESSION_MESSAGE_CAP)
+        ?? DEFAULT_AI_SESSION_MESSAGE_CAP,
+    );
+  } catch {
+    return DEFAULT_AI_SESSION_MESSAGE_CAP;
   }
-  return `${content.slice(0, half)}${marker}${content.slice(content.length - half)}`;
 }
 
 /**
- * Remove `reasoningEncryptedContent` ciphertext from a message's persisted
- * continuation and shed bulk tool output. The ciphertext exists so stateless
- * Responses turns can replay prior reasoning items; tool output dominates
- * persisted size in AI-driven terminal chats. When storage pressure forces
- * it, shedding this bulk keeps the visible conversation intact at the cost of
- * reasoning replay and full tool output for affected messages.
- */
-function stripReasoningEncryptedContent(
-  options: ProviderContinuationOptions,
-): ProviderContinuationOptions | undefined {
-  const hasCiphertext = Object.values(options).some(
-    providerOptions => typeof providerOptions?.reasoningEncryptedContent === 'string',
-  );
-  if (!hasCiphertext) return options;
-  const stripped: ProviderContinuationOptions = {};
-  for (const [provider, providerOptions] of Object.entries(options)) {
-    const rest = { ...providerOptions };
-    delete rest.reasoningEncryptedContent;
-    if (Object.keys(rest).length) stripped[provider] = rest;
-  }
-  return Object.keys(stripped).length ? stripped : undefined;
-}
-
-function stripReasoningCiphertextFromMessage(message: AISession['messages'][number]) {
-  const continuation = message.providerContinuation;
-  if (!continuation?.reasoningParts) return message;
-  let changed = false;
-  const parts = continuation.reasoningParts.map(part => {
-    if (!part.providerOptions) return part;
-    const providerOptions = stripReasoningEncryptedContent(part.providerOptions);
-    if (providerOptions === part.providerOptions) return part;
-    changed = true;
-    return providerOptions ? { text: part.text, providerOptions } : { text: part.text };
-  });
-  if (!changed) return message;
-  return {
-    ...message,
-    providerContinuation: {
-      ...continuation,
-      reasoningParts: parts,
-    },
-  };
-}
-
-function stripEncryptedReasoningFromMessage(message: AISession['messages'][number]) {
-  const strippedContinuationMessage = stripReasoningCiphertextFromMessage(message);
-  const toolResults = strippedContinuationMessage.toolResults;
-  if (!toolResults?.length) return strippedContinuationMessage;
-  let toolResultsChanged = false;
-  const nextToolResults = toolResults.map((result) => {
-    const content = truncatePersistedToolResultContent(result.content);
-    if (content === result.content) return result;
-    toolResultsChanged = true;
-    return { ...result, content };
-  });
-  return toolResultsChanged
-    ? { ...strippedContinuationMessage, toolResults: nextToolResults }
-    : strippedContinuationMessage;
-}
-
-function stripEncryptedReasoningFromSession(session: AISession): AISession {
-  let changed = false;
-  const messages = session.messages.map(message => {
-    const stripped = stripEncryptedReasoningFromMessage(message);
-    if (stripped !== message) changed = true;
-    return stripped;
-  });
-  return changed ? { ...session, messages } : session;
-}
-
-function stripCompactedEncryptedReasoningFromSession(session: AISession): AISession {
-  const compactedMessageCount = Math.min(
-    session.messages.length,
-    Math.max(0, session.contextCompaction?.compactedMessageCount ?? 0),
-  );
-  if (compactedMessageCount === 0) return session;
-
-  let changed = false;
-  const messages = session.messages.map((message, index) => {
-    if (index >= compactedMessageCount) return message;
-    const stripped = stripReasoningCiphertextFromMessage(message);
-    if (stripped !== message) changed = true;
-    return stripped;
-  });
-  return changed ? { ...session, messages } : session;
-}
-
-/**
- * Prune sessions before writing to localStorage to prevent hitting the
- * ~5-10 MB storage quota. Only affects what is persisted — the in-memory
- * state retains all messages until the session is reloaded.
+ * Prune sessions before writing to the persisted store to bound retention.
+ * Only affects what is persisted — the in-memory state retains all messages
+ * until the session is reloaded.
  *
  * - Keeps only the MAX_STORED_SESSIONS most-recently-updated sessions.
- * - Trims each session's messages to the last MAX_SESSION_MESSAGES.
+ * - Trims each session's messages to the last `messageCap` messages.
  */
-export function pruneSessionsForStorage(sessions: AISession[]): AISession[] {
+export function pruneSessionsForStorage(
+  sessions: AISession[],
+  messageCap: number = readAiSessionMessageCap(),
+): AISession[] {
   // Sort by updatedAt descending so we keep the newest
   const sorted = [...sessions].sort((a, b) => b.updatedAt - a.updatedAt);
   const limited = sorted.slice(0, MAX_STORED_SESSIONS);
   return limited.map(s => {
-    if (s.messages.length > MAX_SESSION_MESSAGES) {
+    if (s.messages.length > messageCap) {
       // Do not start the retained tail with a tool result whose assistant call
       // was just trimmed. Reuse the same tool-safe boundary logic as context
       // compaction, even if that retains a few more than the nominal cap.
       const removedMessageCount = findSafeChatMessageCompactionSplitIndex(
         s.messages,
-        MAX_SESSION_MESSAGES,
+        messageCap,
       );
       const contextCompaction = s.contextCompaction
         ? {
@@ -380,150 +289,119 @@ export function prepareRestoredSessions(sessions: AISession[], syncEnabled: bool
   return syncEnabled ? sessions : pruneSessionsForStorage(sessions);
 }
 
-/**
- * Serialize sessions for localStorage under a byte budget, escalating pruning
- * as needed. Returns the JSON to persist plus the (possibly) further-pruned
- * sessions that JSON represents.
- *
- * Degradation ladder, cheapest loss first: strip replay ciphertext, shed bulk
- * tool output (kept at a bounded head+tail per result), and only then drop
- * oldest whole sessions. Evicting visible chats to preserve tool bulk is what
- * emptied history for users under storage pressure.
- */
-export function serializeSessionsForStorage(
-  sessions: AISession[],
-  budgetBytes: number = MAX_SESSIONS_JSON_BYTES,
-): { json: string; sessions: AISession[] } {
-  const prepared = pruneSessionsForStorage(sessions).map(rawSession => {
-    // These messages are replaced by the durable summary before every later
-    // request, so their replay ciphertext can never be used again. Remove it
-    // before deciding whether the newest session deserves full protection;
-    // otherwise dead metadata can evict other visible conversations.
-    const session = stripCompactedEncryptedReasoningFromSession(rawSession);
-    return { session, json: JSON.stringify(session) };
-  });
+// ── IndexedDB persistence (issue #4123) ──
+//
+// Sessions are persisted one record per session. There is no global byte
+// budget and no re-serialization ladder: the 2 MB localStorage budget existed
+// to defend a shared quota against the cost of serializing the whole store on
+// every write, and both are gone with per-record writes. Only a count cap
+// (MAX_STORED_SESSIONS) and the per-session message cap remain.
 
-  // Check whether retained history fits before preparing degradation. Use
-  // the existing JSON string-length budget including array delimiters, and
-  // avoid preparing unused stripped messages and serializing payloads again.
-  const fullLength = 2 + prepared.reduce((total, entry) => total + entry.json.length, 0)
-    + Math.max(0, prepared.length - 1);
-  if (fullLength <= budgetBytes) {
-    return {
-      json: `[${prepared.map(entry => entry.json).join(',')}]`,
-      sessions: prepared.map(entry => entry.session),
-    };
-  }
+/** Last set of sessions known to be persisted, for per-record diffing. */
+let lastPersistedSessionsById: Map<string, AISession> = new Map();
+/** Serialized write queue: IDB operations never interleave. */
+let idbWriteQueue: Promise<void> = Promise.resolve();
 
-  // Reuse the full representation when the unchanged degradation ladder is
-  // needed, including on quota retries with a smaller budget.
-  const serialized = prepared.map(({ session, json }) => {
-    const degradableMessages = session.messages.flatMap((message, index) => {
-      const degradedMessage = stripEncryptedReasoningFromMessage(message);
-      if (degradedMessage === message) return [];
-      return [{
-        index,
-        degradedMessage,
-        jsonLengthDelta: JSON.stringify(degradedMessage).length - JSON.stringify(message).length,
-      }];
-    });
-    const strippedSession = stripEncryptedReasoningFromSession(session);
-    return {
-      session,
-      json,
-      strippedSession,
-      strippedJson: strippedSession === session
-        ? json
-        : JSON.stringify(strippedSession),
-      degradableMessages,
-    };
-  });
+/** Test hook: reset diff state between tests. */
+export function __resetIdbPersistenceForTests() {
+  lastPersistedSessionsById = new Map();
+  idbWriteQueue = Promise.resolve();
+  // Tests swap the fake indexedDB factory between cases; the cached open
+  // handle must not survive the swap.
+  resetAiSessionsIdbForTests();
+  // Tests simulate the post-boot state by default; the boot-gating cases
+  // call __resetAiSessionsHydrationForTests() to go back to pending.
+  markAiSessionsHydrationComplete();
+}
 
-  // Preserve the newest session's full continuation whenever it can fit by
-  // itself. That session is the one the user is most likely continuing now;
-  // older visible history must not make its next tool turn unreplayable.
-  const protectNewestContinuation = serialized.length > 0
-    && serialized[0].json.length + 2 <= budgetBytes;
+/** Test hook: resolve once every queued IndexedDB sync has settled. */
+export function __flushIdbWritesForTests(): Promise<void> {
+  return idbWriteQueue.then(() => undefined, () => undefined);
+}
 
-  // Determine how many sessions can fit using the smallest representation for
-  // older sessions while reserving the newest session's full representation
-  // when possible. This also prevents an old, oversized visible chat that must
-  // be dropped anyway from causing newer replay ciphertext to be stripped.
-  let minimalLength = 2
-    + serialized.reduce((total, entry, index) => (
-      total + (protectNewestContinuation && index === 0 ? entry.json.length : entry.strippedJson.length)
-    ), 0)
-    + Math.max(0, serialized.length - 1);
-  while (minimalLength > budgetBytes && serialized.length > 1) {
-    const removed = serialized.pop();
-    if (!removed) break;
-    minimalLength -= removed.strippedJson.length + 1;
-  }
+// ── Boot hydration signal (issue #4125 review) ──
+//
+// Settles once useAIState's boot load has finished (IndexedDB read, legacy
+// migration, disk-backup restore). Sync collection and the active-pointer
+// validation must not run before it: a pre-hydration collect reads the
+// stale legacy localStorage store and would overwrite newer IndexedDB
+// records, and pointer validation against the initially-empty in-memory
+// array would null every pointer before the real sessions arrive.
 
-  // Then keep full continuation data for the retained sessions and shed
-  // replay-only bulk (ciphertext, oversized tool output) from the oldest
-  // retained sessions only as needed, never touching the protected newest
-  // session. Within one session, shed it one message at a time from oldest to
-  // newest so a long active chat can retain its most recent replayable tool
-  // exchange when that still fits.
-  let jsonLength = 2 + serialized.reduce((total, entry) => total + entry.json.length, 0)
-    + Math.max(0, serialized.length - 1);
-  const firstStrippableIndex = protectNewestContinuation ? 1 : 0;
-  for (
-    let index = serialized.length - 1;
-    index >= firstStrippableIndex && jsonLength > budgetBytes;
-    index -= 1
-  ) {
-    const current = serialized[index];
-    let degradedMessageCount = 0;
-    while (jsonLength > budgetBytes && degradedMessageCount < current.degradableMessages.length) {
-      jsonLength += current.degradableMessages[degradedMessageCount].jsonLengthDelta;
-      degradedMessageCount += 1;
-    }
-    if (degradedMessageCount > 0) {
-      const degradedMessagesByIndex = new Map(
-        current.degradableMessages
-          .slice(0, degradedMessageCount)
-          .map(entry => [entry.index, entry.degradedMessage] as const),
-      );
-      const nextSession = {
-        ...current.session,
-        messages: current.session.messages.map((message, messageIndex) => (
-          degradedMessagesByIndex.get(messageIndex) ?? message
-        )),
-      };
-      const nextJson = JSON.stringify(nextSession);
-      const projectedJsonLength = current.json.length
-        + current.degradableMessages
-          .slice(0, degradedMessageCount)
-          .reduce((total, entry) => total + entry.jsonLengthDelta, 0);
-      jsonLength += nextJson.length - projectedJsonLength;
-      serialized[index] = {
-        ...current,
-        session: nextSession,
-        json: nextJson,
-      };
-    }
-  }
+let aiSessionsHydrationComplete = false;
 
-  return {
-    json: `[${serialized.map(entry => entry.json).join(',')}]`,
-    sessions: serialized.map(entry => entry.session),
-  };
+export function isAiSessionsHydrationComplete(): boolean {
+  return aiSessionsHydrationComplete;
+}
+
+/** Called by useAIState's boot effect when the boot load settles. */
+export function markAiSessionsHydrationComplete(): void {
+  aiSessionsHydrationComplete = true;
+}
+
+/** Test hook: return the hydration signal to the pre-boot (pending) state. */
+export function __resetAiSessionsHydrationForTests(): void {
+  aiSessionsHydrationComplete = false;
+}
+
+/** Seed the diff baseline after a boot load or migration. */
+export function seedLastPersistedSessions(sessions: AISession[]) {
+  lastPersistedSessionsById = new Map(sessions.map(session => [session.id, session]));
 }
 
 /**
- * Persist sessions to localStorage with byte-budgeted primary/overflow slices.
- * Returns true when local history was saved, possibly as a newest-primary
- * fallback with the full history scheduled for disk backup under quota pressure.
+ * Read the persisted session set synchronously. Source of truth is the
+ * in-memory snapshot held by useAIState; this accessor returns the last set
+ * handed to `writeSessionsForStorage`, falling back to the read-only legacy
+ * localStorage store (kept untouched for one release).
  */
+export function getPersistedAiSessionsSnapshot(): AISession[] {
+  if (lastPersistedSessionsById.size > 0) {
+    return Array.from(lastPersistedSessionsById.values())
+      .sort((a, b) => (b.updatedAt ?? 0) - (a.updatedAt ?? 0));
+  }
+  return readLiveSessionsArray(localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS));
+}
 
-// Durability mirror (issue #4015 follow-up): every successful store write
-// also schedules a debounced disk backup so a wiped/recreated profile does
-// not take the chat history with it. Persisted history is mirrored, including
-// overflow sessions, throttled to at most one write per mutation batch.
-// Before a byte-budget drop, mirror the full
-// count-capped set even if the subsequent localStorage writes fail.
+function queueIdbSessionSync(
+  changed: AISession[],
+  removedIds: string[],
+  prevById: Map<string, AISession>,
+  persisted: AISession[],
+) {
+  if (changed.length === 0 && removedIds.length === 0) return;
+  idbWriteQueue = idbWriteQueue
+    .then(async () => {
+      if (!isIndexedDbAvailable()) return;
+      const db = await openAiSessionsIdb();
+      // Per-record write: only the changed sessions are put, only removed
+      // ids are deleted.
+      if (changed.length > 0) await idbPutSessions(db, changed);
+      if (removedIds.length > 0) await idbDeleteSessionIds(db, removedIds);
+      await idbPutMeta(db, 'schemaVersion', 1);
+      await idbPutMeta(db, 'lastWriteAt', Date.now());
+      publishAiSessionsIdbChange();
+    })
+    .catch((error) => {
+      // IndexedDB failures must never break the in-memory session state.
+      // Reset the diff baseline so the next write retries every record, and
+      // fall back to the legacy localStorage key so a corrupt/unavailable
+      // IndexedDB still leaves a restorable trace (via the disk mirror).
+      console.warn('[AIState] IndexedDB session sync failed:', error);
+      lastPersistedSessionsById = new Map(prevById);
+      try {
+        localStorageAdapter.writeString(STORAGE_KEY_AI_SESSIONS, JSON.stringify(persisted));
+      } catch {
+        // Legacy fallback is best-effort too.
+      }
+    });
+}
+
+// Durability mirror (issue #4015 follow-up): every write also schedules a
+// debounced disk backup so a wiped/recreated profile does not take the chat
+// history with it. The persisted JSON is mirrored; when the count cap evicts
+// sessions, a PRE-eviction generation is written first so evicted chats stay
+// recoverable from disk (the blind spot found in issue #4123).
 const backupMirror = new DebouncedBackupMirror((json) => {
   try {
     void getAIBridge()?.aiSessionsBackupWrite?.({ json })?.catch(() => {});
@@ -532,6 +410,14 @@ const backupMirror = new DebouncedBackupMirror((json) => {
   }
 });
 
+let aiSessionsBackupRecoveryPending = false;
+
+/** Partial migration must not rotate away generations holding disk-only chats. */
+export function setAiSessionsBackupRecoveryPending(pending: boolean) {
+  aiSessionsBackupRecoveryPending = pending;
+  if (pending) backupMirror.reset();
+}
+
 export function flushBackupMirror() {
   try {
     backupMirror.flushNow();
@@ -542,9 +428,11 @@ export function flushBackupMirror() {
 
 export function __resetBackupMirrorForTests() {
   backupMirror.reset();
+  aiSessionsBackupRecoveryPending = false;
 }
 
 export function scheduleBackupMirror(json: string) {
+  if (aiSessionsBackupRecoveryPending) return;
   try {
     backupMirror.schedule(json);
   } catch {
@@ -552,257 +440,79 @@ export function scheduleBackupMirror(json: string) {
   }
 }
 
-/**
- * Last successful write: the same immutable sessions array is written again by
- * the debounced save path and by cloud-sync collection, and each write used to
- * re-serialize the whole (often multi-MB) history.
- */
-let lastSessionsWrite: { sessions: AISession[]; synced: boolean; json: string } | null = null;
-
-function rememberSessionsWrite(sessions: AISession[], synced: boolean, json: string): void {
-  lastSessionsWrite = { sessions, synced, json };
-}
-
-function storedSessionsJsonEquals(json: string): boolean {
+/** Write one immediate backup generation (bypasses the debounce window). */
+function writeImmediateBackupGeneration(json: string) {
+  if (aiSessionsBackupRecoveryPending) return;
   try {
-    return localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS) === json;
+    backupMirror.schedule(json);
+    backupMirror.flushNow();
   } catch {
-    return false;
+    // Backup failures must never break chat persistence.
   }
 }
 
-function overflowChunkKey(index: number): string {
-  return index === 0 ? STORAGE_KEY_AI_SESSIONS_OVERFLOW : `${STORAGE_KEY_AI_SESSIONS_OVERFLOW}_${index + 1}`;
-}
-
-function readOverflowChunks(): string[] {
-  const chunks: string[] = [];
-  for (let index = 0; ; index += 1) {
-    const chunk = localStorageAdapter.readString(overflowChunkKey(index));
-    if (chunk == null) return chunks;
-    chunks.push(chunk);
-  }
-}
-
-function clearOverflowChunks(startIndex = 0) {
-  for (let index = startIndex; localStorageAdapter.readString(overflowChunkKey(index)) != null; index += 1) {
-    localStorageAdapter.remove(overflowChunkKey(index));
-  }
-}
-
-function writeDiskOverflowIds(ids: string[]): boolean {
-  if (ids.length > 0) {
-    return localStorageAdapter.write(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW, ids);
-  }
-  if (localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW) != null) {
-    localStorageAdapter.remove(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW);
-  }
-  return true;
-}
-
-/** Replace the entire overflow blob; never leave a partially written JSON array. */
-function replaceOverflowChunks(chunks: string[]): boolean {
-  clearOverflowChunks();
-  let complete = false;
-  try {
-    complete = chunks.every((chunk, index) => (
-      localStorageAdapter.writeString(overflowChunkKey(index), chunk)
-    ));
-    return complete;
-  } finally {
-    if (!complete) clearOverflowChunks();
-  }
-}
-
-/** Read both local retention slices; newer copies win if a session is duplicated. */
-export function readSessionsFromStorage(): AISession[] {
-  return mergeImportedSessions(
-    readLiveSessionsArray(readOverflowChunks().join('')),
-    readLiveSessionsArray(localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS)),
-  );
-}
+/**
+ * Perf (#4121): the exact same immutable sessions array is often written
+ * again by the debounced save path and by cloud-sync collection; skipping
+ * the re-stringify for a reference-identical set keeps that cheap. The
+ * per-record IDB diff below already makes the store write itself cheap.
+ */
+let lastMirroredSessions: AISession[] | null = null;
 
+/**
+ * Persist sessions. Writes go to IndexedDB, one record per session, through a
+ * serialized queue; errors are logged, never thrown. Returns true when the
+ * persisted set was computed (in-memory state remains authoritative either
+ * way).
+ */
 export function writeSessionsForStorage(
   sessions: AISession[],
-  options: { deletedSessionIds?: readonly string[] } = {},
+  options?: { deletedSessionIds?: readonly string[] },
 ): boolean {
-  const synced = Boolean(
-    localStorageAdapter.read<{ enabled?: boolean }>(STORAGE_KEY_CLOUD_SYNC_AI_SESSIONS)?.enabled,
-  );
-  // Nothing to do when this exact array was already written in this mode and
-  // storage still holds that write (another window may have replaced it).
-  if (
-    lastSessionsWrite?.sessions === sessions
-    && lastSessionsWrite.synced === synced
-    && storedSessionsJsonEquals(lastSessionsWrite.json)
-    // A matching primary alone cannot establish that overflow is intact.
-    && localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS_OVERFLOW) == null
-    && localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW) == null
-  ) {
-    return true;
-  }
-  // Synced records are authoritative after restart: silently evicting a
-  // session or turn here would turn local retention into cloud deletion.
-  if (synced) {
-    const json = JSON.stringify(sessions);
-    const previousChunks = readOverflowChunks();
-    // The authoritative primary replaces overflow, so free its quota first.
-    clearOverflowChunks();
-    let syncedOk = false;
-    try {
-      syncedOk = localStorageAdapter.writeString(STORAGE_KEY_AI_SESSIONS, json);
-      if (syncedOk) {
-        clearOverflowChunks();
-        if (localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW) != null) {
-          localStorageAdapter.remove(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW);
-        }
-        scheduleBackupMirror(json);
-        rememberSessionsWrite(sessions, true, json);
-      }
-      return syncedOk;
-    } finally {
-      if (!syncedOk) replaceOverflowChunks(previousChunks);
-    }
-  }
-  const inputIds = new Set(sessions.map(session => session.id));
-  const pruned = pruneSessionsForStorage(sessions);
-  const retainedIds = new Set(pruned.map(session => session.id));
-  const deletedIds = new Set(options.deletedSessionIds);
-  // A live write can race startup's backup read. Preserve marker IDs absent
-  // from the live input unless explicitly deleted. IDs present in the input
-  // are resolved even if the count cap evicts them; pending IDs block mirroring.
-  const diskOverflowIds = localStorageAdapter.read<unknown>(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW);
-  const unresolvedDiskIds: string[] = Array.isArray(diskOverflowIds)
-    ? diskOverflowIds.filter((id): id is string => (
-      typeof id === 'string' && !retainedIds.has(id) && !deletedIds.has(id) && !inputIds.has(id)
-    ))
-    : [];
-  let fullBackupScheduled = false;
-  const ensureFullBackup = () => {
-    if (!fullBackupScheduled && unresolvedDiskIds.length === 0) {
-      scheduleBackupMirror(JSON.stringify(pruned));
-      fullBackupScheduled = true;
-    }
-  };
-  const persistCandidate = (
-    candidate: { json: string; sessions: AISession[] },
-    budget: number,
-    chunkBudget = budget,
-  ): boolean => {
-    const primaryIds = new Set(candidate.sessions.map(session => session.id));
-    const omitted = pruned.filter(session => !primaryIds.has(session.id));
-    if (omitted.length > 0) ensureFullBackup();
-    // Apply the same replay-bulk ladder to every overflow chat as budgets
-    // tighten. Chunking alone cannot reduce an origin's aggregate quota use.
-    const overflow = omitted.map(session => serializeSessionsForStorage([session], budget).sessions[0]);
-    const overflowJson = overflow.length > 0 ? JSON.stringify(overflow) : '';
-    // Split the array's JSON string, so even one oversized session can span
-    // chunks without losing messages. Concatenate all chunks before parsing.
-    const chunks: string[] = [];
-    // Primary budgets can shrink to a tiny empty chat. Keep overflow writes
-    // bounded independently while still supporting small per-key quotas.
-    const chunkSize = Math.max(32 * 1024, chunkBudget);
-    for (let offset = 0; offset < overflowJson.length; offset += chunkSize) {
-      chunks.push(overflowJson.slice(offset, offset + chunkSize));
-    }
-    const previousChunks = readOverflowChunks();
-    const previousPrimary = localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS);
-    let primaryWritten = false;
-    let persisted = false;
-    try {
-      // Reclaim both old slices before writing overflow: the final history may
-      // fit even when overflow plus the old, larger primary would exceed quota.
-      clearOverflowChunks();
-      if (!localStorageAdapter.writeString(STORAGE_KEY_AI_SESSIONS, candidate.json)) return false;
-      primaryWritten = true;
-      if (!replaceOverflowChunks(chunks)) return false;
-      if (!writeDiskOverflowIds(unresolvedDiskIds)) return false;
-      persisted = true;
-      if (!fullBackupScheduled && unresolvedDiskIds.length === 0) scheduleBackupMirror(candidate.json);
-      rememberSessionsWrite(sessions, false, candidate.json);
-      return true;
-    } finally {
-      if (!persisted) {
-        clearOverflowChunks();
-        if (primaryWritten) {
-          if (previousPrimary == null) localStorageAdapter.remove(STORAGE_KEY_AI_SESSIONS);
-          else localStorageAdapter.writeString(STORAGE_KEY_AI_SESSIONS, previousPrimary);
-        }
-        replaceOverflowChunks(previousChunks);
-      }
-    }
-  };
-  const primaryCandidates: { json: string; sessions: AISession[] }[] = [];
-  let previousLength = Number.POSITIVE_INFINITY;
-  for (const configuredBudget of [MAX_SESSIONS_JSON_BYTES, ...RETRY_SESSIONS_JSON_BYTES]) {
-    // A real quota failure means the next attempt must be smaller even when
-    // the failed payload was already below the nominal retry budget. Reduce
-    // materially on each bounded retry so several small sessions can be
-    // removed before the retry sequence is exhausted.
-    const reducedBudget = Number.isFinite(previousLength)
-      ? Math.floor(previousLength * 0.75)
-      : configuredBudget;
-    const budget = Math.min(configuredBudget, reducedBudget);
-    if (budget < 2) break;
-    const candidate = serializeSessionsForStorage(pruned, budget);
-    primaryCandidates.push(candidate);
-    // Even an unchanged primary can succeed with smaller overflow chunks or
-    // more degraded overflow replay data at this retry budget.
-    if (persistCandidate(candidate, budget)) return true;
-    previousLength = candidate.json.length;
-  }
-  // Last resort: use the smallest primary representation (the newest chat
-  // with replay-only bulk removed), retaining other chats in overflow.
-  const minimalCandidate = serializeSessionsForStorage(pruned, 0);
-  const minimalChunkBudget = Math.min(minimalCandidate.json.length, RETRY_SESSIONS_JSON_BYTES[RETRY_SESSIONS_JSON_BYTES.length - 1]);
-  primaryCandidates.push(minimalCandidate);
-  if (persistCandidate(minimalCandidate, 0, minimalChunkBudget)) return true;
-
-  // If the complete retained set cannot fit, save the newest primary anyway.
-  // Schedule the full disk mirror before discarding overflow; do not let an
-  // old valid primary block persistence of every subsequent conversation turn.
-  ensureFullBackup();
-  const previousChunks = readOverflowChunks();
-  const previousPrimary = localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS);
-  const previousDiskOverflow = localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW);
-  clearOverflowChunks();
-  let primaryWritten = false;
-  let primaryPersisted = false;
   try {
-    for (const candidate of primaryCandidates) {
-      const primaryIds = new Set(candidate.sessions.map(session => session.id));
-      const diskOnlyIds = [...new Set([
-        ...unresolvedDiskIds,
-        ...pruned.filter(session => !primaryIds.has(session.id)).map(session => session.id),
-      ])];
-      // Replacing a large old primary can free the space needed by metadata.
-      // Roll it back below if the recovery marker still cannot be persisted.
-      if (!localStorageAdapter.writeString(STORAGE_KEY_AI_SESSIONS, candidate.json)) continue;
-      primaryWritten = true;
-      if (writeDiskOverflowIds(diskOnlyIds)) {
-        primaryPersisted = true;
-        rememberSessionsWrite(sessions, false, candidate.json);
-        return true;
-      }
+    // Explicitly deleted ids never count as cap eviction (they also must not
+    // trigger a pre-eviction backup generation).
+    for (const id of options?.deletedSessionIds ?? []) intentionallyDeletedSessionIds.add(id);
+    // Synced records are authoritative after restart: never prune them, or
+    // local retention would turn into cloud deletion on the next sync.
+    const syncEnabled = !!localStorageAdapter.read<{ enabled?: boolean }>(
+      STORAGE_KEY_CLOUD_SYNC_AI_SESSIONS,
+    )?.enabled;
+    const persisted = syncEnabled ? sessions : pruneSessionsForStorage(sessions);
+
+    const prevById = lastPersistedSessionsById;
+    const persistedIds = new Set(persisted.map(session => session.id));
+
+    // Count-cap eviction: sessions that drop out of the persisted set without
+    // being explicitly deleted get a pre-eviction disk generation containing
+    // the full pre-eviction store, so they remain recoverable.
+    const evicted = Array.from(prevById.entries())
+      .filter(([id]) => !persistedIds.has(id) && !intentionallyDeletedSessionIds.has(id))
+      .map(([, session]) => session);
+    intentionallyDeletedSessionIds.clear();
+    if (evicted.length > 0) {
+      writeImmediateBackupGeneration(JSON.stringify(sessions));
+      console.warn(
+        `[AIState] Retention cap evicted ${evicted.length} session(s); a pre-eviction backup generation was written to disk.`,
+      );
     }
-  } finally {
-    if (!primaryPersisted) {
-      if (primaryWritten) {
-        if (previousPrimary == null) localStorageAdapter.remove(STORAGE_KEY_AI_SESSIONS);
-        else localStorageAdapter.writeString(STORAGE_KEY_AI_SESSIONS, previousPrimary);
-      }
-      if (previousDiskOverflow != null) {
-        localStorageAdapter.writeString(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW, previousDiskOverflow);
-      } else if (localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW) != null) {
-        localStorageAdapter.remove(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW);
-      }
-      replaceOverflowChunks(previousChunks);
+
+    // Per-record diff (synchronous: the baseline must advance even when
+    // IndexedDB is unavailable, and callers read the snapshot right after).
+    const changed = persisted.filter(session => prevById.get(session.id) !== session);
+    const removedIds = Array.from(prevById.keys()).filter(id => !persistedIds.has(id));
+    lastPersistedSessionsById = new Map(persisted.map(session => [session.id, session]));
+
+    if (changed.length > 0 || removedIds.length > 0 || lastMirroredSessions !== persisted) {
+      scheduleBackupMirror(JSON.stringify(persisted));
+      lastMirroredSessions = persisted;
     }
+    queueIdbSessionSync(changed, removedIds, prevById, persisted);
+    return true;
+  } catch (error) {
+    console.warn('[AIState] Failed to persist AI sessions:', error);
+    return false;
   }
-  console.warn(
-    '[AIState] Failed to persist AI sessions within the storage quota; recent chat history may not survive a restart.',
-  );
-  return false;
 }
 
 export let latestAISessionsSnapshot: AISession[] | null = null;
@@ -844,10 +554,10 @@ export function setLatestAIActiveSessionMapSnapshot(activeSessionIdMap: Record<s
 
 export function prewarmAIStateStorageSnapshots() {
   try {
-    if (latestAISessionsSnapshot === null) {
-      latestAISessionsSnapshot =
-        readSessionsFromStorage();
-    }
+    // Sessions are no longer prewarmed from localStorage: the primary store is
+    // IndexedDB and loads asynchronously in useAIState. Prewarming the stale
+    // read-only legacy key would make the boot loader skip the IndexedDB
+    // contents ("never restore over non-empty live state").
     if (latestAIActiveSessionMapSnapshot === null) {
       latestAIActiveSessionMapSnapshot =
         localStorageAdapter.read<Record<string, string | null>>(STORAGE_KEY_AI_ACTIVE_SESSION_MAP) ?? {};

application/state/commandHistoryStore.test.ts

@@ -1,5 +1,6 @@
 import test from "node:test";
 import assert from "node:assert/strict";
+import type { HistoryEntry } from "./commandHistoryStore";
 
 import {
   STORAGE_KEY_COMMAND_HISTORY,
@@ -73,7 +74,9 @@ const {
   getCommandHistoryClearGeneration,
   hasCommandHistoryBeenCleared,
   markCommandHistoryCleared,
+  fuzzyQueryHistory,
   queryHistory,
+  queryRecentHistoryByCommand,
   recordCommand,
   subscribeCommandHistoryCleared,
 } = await import("./commandHistoryStore.ts");
@@ -343,3 +346,155 @@ test("saving after a command and peer writes read the clear generation without p
   parse.mock.restore();
   assert.ok(queryHistory("echo fast", { hostId: "host-fast" }).some((entry) => entry.command === "echo fast-path-2"));
 });
+
+const QUERY_NOW = 1_700_000_000_000;
+const DAY_MS = 24 * 60 * 60 * 1000;
+
+function historyEntry(command: string, overrides: Partial<HistoryEntry> = {}): HistoryEntry {
+  return {
+    command, hostId: "host-1", os: "linux", frequency: 1,
+    createdAt: QUERY_NOW, lastUsedAt: QUERY_NOW, ...overrides,
+  };
+}
+
+function installHistoryEntries(entries: HistoryEntry[]): void {
+  clearHistory();
+  const raw = JSON.stringify({
+    clearGeneration: getCommandHistoryClearGeneration(), version: 1, entries,
+  });
+  storage.set(COMMAND_HISTORY_STORAGE_KEY, raw);
+  dispatchStorageEvent(COMMAND_HISTORY_STORAGE_KEY, raw);
+}
+
+test("prefix history preserves relevance, stable ties, host isolation and best duplicate", (t) => {
+  t.mock.method(Date, "now", () => QUERY_NOW);
+  const entries = [
+    historyEntry("vi", { frequency: 100 }),
+    historyEntry("vim duplicate"),
+    historyEntry("vim frequent", { frequency: 8, lastUsedAt: QUERY_NOW - DAY_MS }),
+    historyEntry("Vim case"),
+    historyEntry("vim tied"),
+    historyEntry("vim duplicate", { hostId: "host-2", frequency: 5 }),
+    historyEntry("unrelated", { frequency: 100 }),
+  ];
+  installHistoryEntries(entries);
+
+  assert.deepEqual(queryHistory("vi", { limit: 4 }), [entries[5], entries[2], entries[3], entries[4]]);
+  assert.deepEqual(queryHistory("vi", { hostId: "host-1", limit: 3 }), [entries[2], entries[1], entries[3]]);
+  assert.deepEqual(queryHistory("VI", { limit: 1 }), [entries[0]]);
+  assert.deepEqual(queryHistory("missing"), []);
+  assert.deepEqual(queryHistory("vi", { limit: 0 }), []);
+});
+
+test("top-k history replaces and evicts duplicates without losing distinct results", (t) => {
+  t.mock.method(Date, "now", () => QUERY_NOW);
+  const entries = [
+    historyEntry("vim a", { frequency: 2 }),
+    historyEntry("vim b", { frequency: 3 }),
+    historyEntry("vim c", { frequency: 4 }),
+    historyEntry("vim b", { hostId: "host-2", frequency: 5 }),
+    historyEntry("vim a", { hostId: "host-2", frequency: 6 }),
+    historyEntry("vim a", { hostId: "host-3", frequency: 1 }),
+  ];
+  installHistoryEntries(entries);
+  assert.deepEqual(queryHistory("vi", { limit: 2 }), [entries[4], entries[3]]);
+  assert.deepEqual(fuzzyQueryHistory("vi", { limit: 2 }), [entries[4], entries[3]]);
+});
+
+test("fuzzy history preserves subsequence quality, recency, exclusions and stable ties", (t) => {
+  t.mock.method(Date, "now", () => QUERY_NOW);
+  const entries = [
+    historyEntry("vi", { frequency: 100 }),
+    historyEntry("vi alpha"),
+    historyEntry("vi beta"),
+    historyEntry("very indirect", { frequency: 2 }),
+    historyEntry("vi stale", { lastUsedAt: QUERY_NOW - DAY_MS }),
+    historyEntry("vi alpha", { hostId: "host-2", frequency: 3 }),
+    historyEntry("iv does not match"),
+  ];
+  installHistoryEntries(entries);
+  assert.deepEqual(fuzzyQueryHistory("vi", { limit: 4 }), [entries[5], entries[3], entries[2], entries[4]]);
+  assert.deepEqual(fuzzyQueryHistory("vi", { hostId: "host-1", limit: 4 }), [entries[3], entries[1], entries[2], entries[4]]);
+  assert.deepEqual(fuzzyQueryHistory(""), []);
+  assert.deepEqual(fuzzyQueryHistory("vi", { limit: -1 }), []);
+});
+
+test("recent history preserves timestamps, command boundaries and quoted argument prefixes", () => {
+  const entries = [
+    historyEntry("cd /work/older", { lastUsedAt: QUERY_NOW - DAY_MS }),
+    historyEntry("cd '/work/new folder'"),
+    historyEntry("CD /work/tied"),
+    historyEntry("cd /work/older", { hostId: "host-2", lastUsedAt: QUERY_NOW + 1 }),
+    historyEntry("cd /other", { lastUsedAt: QUERY_NOW + 2 }),
+    historyEntry("cdb /work/wrong", { lastUsedAt: QUERY_NOW + 3 }),
+    historyEntry("cd /work/excluded", { lastUsedAt: QUERY_NOW + 4 }),
+  ];
+  installHistoryEntries(entries);
+  const options = { commandName: " CD ", argumentPrefix: "'/work/", excludeCommand: "cd /work/excluded", limit: 3 };
+  assert.deepEqual(queryRecentHistoryByCommand(options), [entries[3], entries[1], entries[2]]);
+  assert.deepEqual(queryRecentHistoryByCommand({ ...options, hostId: "host-1" }), [entries[1], entries[2], entries[0]]);
+  assert.deepEqual(queryRecentHistoryByCommand({ commandName: "" }), []);
+  assert.deepEqual(queryRecentHistoryByCommand({ commandName: "cd", limit: 0 }), []);
+});
+
+test("fuzzy scoring preserves consecutive and word-boundary bonuses across long gaps", (t) => {
+  t.mock.method(Date, "now", () => QUERY_NOW);
+  const entries = [
+    historyEntry("av-x"),
+    historyEntry("avx"),
+    historyEntry(`v${"a".repeat(1900)}x`),
+    historyEntry("v-x"),
+    historyEntry("v/x"),
+    historyEntry("v_x"),
+    historyEntry("v x"),
+    historyEntry("vx adjacent"),
+    historyEntry("v missing second character"),
+    historyEntry("xv wrong order"),
+  ];
+  installHistoryEntries(entries);
+  assert.deepEqual(fuzzyQueryHistory("vx"), [
+    entries[7], entries[3], entries[4], entries[5], entries[6], entries[2], entries[1], entries[0],
+  ]);
+  assert.deepEqual(fuzzyQueryHistory("vv"), []);
+});
+
+for (const size of [4_000, 40_000]) {
+  test(`history queries keep five best results with linear scoring for ${size} entries`, (t) => {
+    t.mock.method(Date, "now", () => QUERY_NOW);
+    const entries = Array.from({ length: size }, (_, i) => historyEntry(`vi file-${i}`, {
+      // Unsorted scores/timestamps, with the best match at the end of the store.
+      frequency: i === size - 1 ? size + 1 : (i * 7919) % size + 1,
+      lastUsedAt: QUERY_NOW + (i === size - 1 ? size + 1 : (i * 7919) % size),
+    }));
+    installHistoryEntries(entries);
+    queryHistory("missing"); // Warm the cache before measuring query operations.
+
+    const expected = entries.slice().sort((a, b) => b.frequency - a.frequency).slice(0, 5);
+    const pow = t.mock.method(Math, "pow");
+    const lower = t.mock.method(String.prototype, "toLowerCase");
+    // node:test cannot mock methods directly on arrays (including Array.prototype).
+    const originalSort = Array.prototype.sort;
+    const sortedSizes: number[] = [];
+    Array.prototype.sort = function<T>(this: T[], compare?: (a: T, b: T) => number): T[] {
+      sortedSizes.push(this.length);
+      return originalSort.call(this, compare);
+    };
+    t.after(() => { Array.prototype.sort = originalSort; });
+    const queries = [
+      () => queryHistory("vi", { limit: 5 }),
+      () => fuzzyQueryHistory("vi", { limit: 5 }),
+      () => queryRecentHistoryByCommand({ commandName: "vi", argumentPrefix: "file-", limit: 5 }),
+    ];
+
+    for (const query of queries) {
+      const beforePow = pow.mock.callCount();
+      const beforeLower = lower.mock.callCount();
+      const result = query();
+      assert.deepEqual(result, expected);
+      assert.equal(new Set(result.map((entry) => entry.command)).size, 5);
+      assert.ok(pow.mock.callCount() - beforePow <= size, "score each entry at most once");
+      assert.ok(lower.mock.callCount() - beforeLower <= 2 * size + 2, "normalize in one linear pass");
+    }
+    assert.deepEqual(sortedSizes, [], "never sort all matches before limiting");
+  });
+}

application/state/commandHistoryStore.ts

@@ -352,6 +352,36 @@ export interface RecentHistoryQueryOptions extends HistoryQueryOptions {
   argumentPrefix?: string;
 }
 
+interface RankedHistoryEntry {
+  entry: HistoryEntry;
+  score: number;
+}
+
+/**
+ * Keep only the best k distinct commands. Queries score each match once and
+ * retain O(k) candidates instead of sorting/allocating all matches (k is 5
+ * for autocomplete). Entries arrive in store order for stable score ties.
+ */
+function retainHistoryMatch(
+  best: RankedHistoryEntry[],
+  entry: HistoryEntry,
+  score: number,
+  limit: number,
+): void {
+  if (best.length >= limit && score <= best[best.length - 1].score) return;
+
+  const duplicate = best.findIndex((candidate) => candidate.entry.command === entry.command);
+  if (duplicate >= 0) {
+    if (score <= best[duplicate].score) return;
+    best.splice(duplicate, 1);
+  }
+
+  // Insert after equal scores to preserve the original store order on ties.
+  const index = best.findIndex((candidate) => score > candidate.score);
+  if (best.length >= limit) best.pop();
+  best.splice(index < 0 ? best.length : index, 0, { entry, score });
+}
+
 /**
  * Query history entries matching a prefix.
  * Returns entries sorted by relevance (frequency * recency).
@@ -366,33 +396,17 @@ export function queryHistory(
   const lowerPrefix = prefix.toLowerCase();
   const now = Date.now(); // Cache once per query
 
-  const filtered = store.entries.filter((entry) => {
+  const best: RankedHistoryEntry[] = [];
+  for (const entry of store.entries) {
+    if (hostId && entry.hostId !== hostId) continue;
     // Must match prefix
-    if (!entry.command.toLowerCase().startsWith(lowerPrefix)) return false;
+    if (!entry.command.toLowerCase().startsWith(lowerPrefix)) continue;
     // Must not be identical to prefix
-    if (entry.command === prefix) return false;
-
-    // Host filtering: strict per-host isolation
-    if (hostId) {
-      return entry.hostId === hostId;
-    }
-    return true;
-  });
-
-  // Sort by score (frequency * recency)
-  filtered.sort((a, b) => scoreEntryAt(b, now) - scoreEntryAt(a, now));
-
-  // Deduplicate by command text (keep highest scored)
-  const seen = new Set<string>();
-  const results: HistoryEntry[] = [];
-  for (const entry of filtered) {
-    if (seen.has(entry.command)) continue;
-    seen.add(entry.command);
-    results.push(entry);
-    if (results.length >= limit) break;
+    if (entry.command === prefix) continue;
+    retainHistoryMatch(best, entry, scoreEntryAt(entry, now), limit);
   }
 
-  return results;
+  return best.map(({ entry }) => entry);
 }
 
 /**
@@ -410,7 +424,7 @@ export function fuzzyQueryHistory(
   const lowerQuery = query.toLowerCase();
   const now = Date.now(); // Cache once per query
 
-  const scored: { entry: HistoryEntry; matchScore: number }[] = [];
+  const best: RankedHistoryEntry[] = [];
 
   for (const entry of store.entries) {
     // Host filtering
@@ -420,24 +434,11 @@ export function fuzzyQueryHistory(
 
     const matchScore = fuzzyScore(lowerQuery, entry.command.toLowerCase());
     if (matchScore > 0 && entry.command !== query) {
-      scored.push({ entry, matchScore });
+      retainHistoryMatch(best, entry, matchScore * scoreEntryAt(entry, now), limit);
     }
   }
 
-  scored.sort((a, b) =>
-    b.matchScore * scoreEntryAt(b.entry, now) - a.matchScore * scoreEntryAt(a.entry, now),
-  );
-
-  const seen = new Set<string>();
-  const results: HistoryEntry[] = [];
-  for (const { entry } of scored) {
-    if (seen.has(entry.command)) continue;
-    seen.add(entry.command);
-    results.push(entry);
-    if (results.length >= limit) break;
-  }
-
-  return results;
+  return best.map(({ entry }) => entry);
 }
 
 /**
@@ -462,38 +463,26 @@ export function queryRecentHistoryByCommand(
   const commandPrefix = `${trimmedCommandName} `;
   const normalizedArgumentPrefix = normalizeArgumentToken(argumentPrefix ?? "");
 
-  const filtered = store.entries.filter((entry) => {
+  const best: RankedHistoryEntry[] = [];
+  for (const entry of store.entries) {
+    if (hostId && entry.hostId !== hostId) continue;
     const lowerCommand = entry.command.toLowerCase();
     if (lowerCommand !== trimmedCommandName && !lowerCommand.startsWith(commandPrefix)) {
-      return false;
+      continue;
     }
-    if (excludeCommand && entry.command === excludeCommand) return false;
+    if (excludeCommand && entry.command === excludeCommand) continue;
 
     if (normalizedArgumentPrefix) {
       const currentToken = normalizeArgumentToken(getCurrentCommandToken(entry.command));
       if (!currentToken.startsWith(normalizedArgumentPrefix)) {
-        return false;
+        continue;
       }
     }
 
-    if (hostId) {
-      return entry.hostId === hostId;
-    }
-    return true;
-  });
-
-  filtered.sort((a, b) => b.lastUsedAt - a.lastUsedAt);
-
-  const seen = new Set<string>();
-  const results: HistoryEntry[] = [];
-  for (const entry of filtered) {
-    if (seen.has(entry.command)) continue;
-    seen.add(entry.command);
-    results.push(entry);
-    if (results.length >= limit) break;
+    retainHistoryMatch(best, entry, entry.lastUsedAt, limit);
   }
 
-  return results;
+  return best.map(({ entry }) => entry);
 }
 
 function getCurrentCommandToken(command: string): string {
@@ -569,28 +558,28 @@ function fuzzyScore(query: string, target: string): number {
   if (query.length > target.length) return 0;
 
   let score = 0;
-  let queryIdx = 0;
+  let searchFrom = 0;
   let prevMatchIdx = -2;
 
-  for (let i = 0; i < target.length && queryIdx < query.length; i++) {
-    if (target[i] === query[queryIdx]) {
-      queryIdx++;
-      // First character bonus
-      if (i === 0) score += 10;
-      // Consecutive match bonus
-      if (i === prevMatchIdx + 1) score += 5;
-      // Word boundary bonus
-      if (i === 0 || target[i - 1] === " " || target[i - 1] === "/" ||
-          target[i - 1] === "-" || target[i - 1] === "_") {
-        score += 3;
-      }
-      score += 1;
-      prevMatchIdx = i;
+  for (let queryIdx = 0; queryIdx < query.length; queryIdx++) {
+    // Skip unmatched runs in native string search, especially for long commands.
+    const i = target.indexOf(query[queryIdx], searchFrom);
+    if (i < 0) return 0;
+    // First character bonus
+    if (i === 0) score += 10;
+    // Consecutive match bonus
+    if (i === prevMatchIdx + 1) score += 5;
+    // Word boundary bonus
+    if (i === 0 || target[i - 1] === " " || target[i - 1] === "/" ||
+        target[i - 1] === "-" || target[i - 1] === "_") {
+      score += 3;
     }
+    score += 1;
+    prevMatchIdx = i;
+    searchFrom = i + 1;
   }
 
-  // All query characters must be matched
-  return queryIdx === query.length ? score : 0;
+  return score;
 }
 
 /**

application/state/pluginContributionContexts.test.ts

@@ -75,6 +75,95 @@ test('resolves the focused workspace session for global keybindings', () => {
   });
 });
 
+test('uses the anchor chat owner when focus is missing (#4098 phase 2)', () => {
+  const splitWorkspace: Workspace = {
+    id: 'workspace-1',
+    title: 'Workspace',
+    anchorChatId: 'chat-2',
+    root: {
+      id: 'split-1',
+      type: 'split',
+      direction: 'vertical',
+      children: [
+        { id: 'pane-1', type: 'pane', sessionId: 'session-1' },
+        { id: 'pane-2', type: 'pane', sessionId: 'session-3' },
+      ],
+      sizes: [1, 1],
+    },
+  };
+  const chatOwnerSessions: TerminalSession[] = [
+    ...sessions,
+    {
+      id: 'session-3',
+      hostId: 'host-3',
+      hostLabel: 'Host 3',
+      username: 'root',
+      hostname: 'example.org',
+      status: 'connected',
+      protocol: 'ssh',
+      workspaceId: 'workspace-1',
+    },
+  ];
+
+  assert.equal(
+    resolveActivePluginKeybindingContext({
+      activeTabId: 'workspace-1',
+      sessions: chatOwnerSessions,
+      workspaces: [splitWorkspace],
+      aiSessions: [
+        { id: 'chat-2', scope: { type: 'terminal', targetId: 'session-3' }, updatedAt: 2 },
+        { id: 'chat-1', scope: { type: 'terminal', targetId: 'session-1' }, updatedAt: 1 },
+      ],
+    })['terminal.sessionId'],
+    // anchorChatId's chat is terminal-scoped to session-3, which wins even
+    // though session-1's chat is older and session-1 is the first member.
+    'session-3',
+  );
+});
+
+test('falls back to the most-recently-active member when there is no anchor (#4098 phase 2)', () => {
+  const splitWorkspace: Workspace = {
+    id: 'workspace-1',
+    title: 'Workspace',
+    root: {
+      id: 'split-1',
+      type: 'split',
+      direction: 'vertical',
+      children: [
+        { id: 'pane-1', type: 'pane', sessionId: 'session-1' },
+        { id: 'pane-2', type: 'pane', sessionId: 'session-3' },
+      ],
+      sizes: [1, 1],
+    },
+  };
+  const chatOwnerSessions: TerminalSession[] = [
+    ...sessions,
+    {
+      id: 'session-3',
+      hostId: 'host-3',
+      hostLabel: 'Host 3',
+      username: 'root',
+      hostname: 'example.org',
+      status: 'connected',
+      protocol: 'ssh',
+      workspaceId: 'workspace-1',
+    },
+  ];
+
+  assert.equal(
+    resolveActivePluginKeybindingContext({
+      activeTabId: 'workspace-1',
+      sessions: chatOwnerSessions,
+      workspaces: [splitWorkspace],
+      aiSessions: [
+        { id: 'chat-1', scope: { type: 'terminal', targetId: 'session-1' }, updatedAt: 1 },
+        { id: 'chat-2', scope: { type: 'terminal', targetId: 'session-3' }, updatedAt: 9 },
+      ],
+    })['terminal.sessionId'],
+    'session-3',
+  );
+});
+
 test('resolves standalone sessions and fails closed for non-terminal tabs', () => {
   assert.equal(
     resolveActivePluginKeybindingContext({ activeTabId: 'session-2', sessions, workspaces })['terminal.sessionId'],
@@ -89,3 +178,18 @@ test('resolves standalone sessions and fails closed for non-terminal tabs', () =
     'netcatty.activeTabId': 'vault',
   });
 });
+
+
+test('empty workspace does not target the detached owner of its anchored chat', () => {
+  const context = resolveActivePluginKeybindingContext({
+    activeTabId: 'workspace-1',
+    sessions: sessions.map((session) => ({ ...session, workspaceId: undefined })),
+    workspaces: [{ ...workspaces[0], focusedSessionId: undefined, anchorChatId: 'chat-1', root: {
+      id: 'empty', type: 'split', direction: 'vertical', children: [], sizes: [],
+    } }],
+    aiSessions: [{ id: 'chat-1', scope: { type: 'terminal', targetId: 'session-1' }, updatedAt: 1 }],
+  });
+  assert.equal(context['terminal.sessionId'], undefined);
+  assert.equal(context['host.id'], undefined);
+  assert.equal(context['workspace.id'], 'workspace-1');
+});

application/state/pluginContributionContexts.ts

@@ -1,4 +1,6 @@
 import { collectSessionIds } from '../../domain/workspace';
+import { resolveMostRecentlyActiveMemberTerminalId } from '../../domain/aiSessionRecency';
+import type { AIChatRecencyEntry } from '../../domain/aiSessionRecency';
 import type { TerminalSession, Workspace } from '../../types';
 
 export type PluginContributionContextValue = string | boolean | number | null;
@@ -44,14 +46,17 @@ export function resolveActivePluginKeybindingContext({
   activeTabId,
   sessions,
   workspaces,
+  aiSessions,
 }: {
   activeTabId: string;
   sessions: readonly TerminalSession[];
   workspaces: readonly Workspace[];
+  /** AI chat snapshot: resolves the workspace anchor and recency fallback (#4098 phase 2). */
+  aiSessions?: readonly AIChatRecencyEntry[];
 }): PluginContributionContext {
   const workspace = workspaces.find((candidate) => candidate.id === activeTabId);
   const activeSessionId = workspace
-    ? (workspace.focusedSessionId ?? collectSessionIds(workspace.root)[0])
+    ? resolveWorkspaceActiveTerminalId(workspace, aiSessions)
     : sessions.some((candidate) => candidate.id === activeTabId)
       ? activeTabId
       : undefined;
@@ -72,3 +77,32 @@ export function resolveActivePluginKeybindingContext({
     'netcatty.activeTabId': activeTabId,
   };
 }
+
+/**
+ * Issue #4098 phase 2: the keybinding context's workspace session resolves by
+ * id, never positionally — focused member first, then the terminal member that
+ * owns the anchored chat, then the most-recently-active member by chat recency.
+ */
+function resolveWorkspaceActiveTerminalId(
+  workspace: Workspace,
+  aiSessions: readonly AIChatRecencyEntry[] | undefined,
+): string | undefined {
+  if (workspace.focusedSessionId && collectSessionIds(workspace.root).includes(workspace.focusedSessionId)) {
+    return workspace.focusedSessionId;
+  }
+
+  const memberTerminalIds = collectSessionIds(workspace.root);
+  if (memberTerminalIds.length === 1) {
+    // A single-member workspace has exactly one candidate — not a positional
+    // pick among many.
+    return memberTerminalIds[0];
+  }
+  const anchorChat = workspace.anchorChatId
+    ? aiSessions?.find((session) => session.id === workspace.anchorChatId && session.scope?.type === 'terminal')
+    : undefined;
+
+  const anchorOwner = anchorChat?.scope.targetId;
+  return (anchorOwner && memberTerminalIds.includes(anchorOwner) ? anchorOwner : undefined)
+    ?? resolveMostRecentlyActiveMemberTerminalId({ memberTerminalIds, aiSessions })
+    ?? undefined;
+}

application/state/sessionSnapshotStore.ts

@@ -45,6 +45,7 @@ export type SessionSnapshotActions = Pick<
   | 'resetWorkspaceRename'
   | 'removeSessionFromWorkspace'
   | 'setWorkspaceFocusedSession'
+  | 'setWorkspaceAnchorChat'
   | 'toggleWorkspaceViewMode'
   // Terminal / chrome mutators previously read only via App session runtime.
   | 'createLocalTerminal'
@@ -56,6 +57,7 @@ export type SessionSnapshotActions = Pick<
   | 'createWorkspaceWithHosts'
   | 'createWorkspaceFromSessions'
   | 'addSessionToWorkspace'
+  | 'moveWorkspacePane'
   | 'appendHostToWorkspace'
   | 'appendHostToWorkspaceConfirmed'
   | 'appendLocalTerminalToWorkspace'

application/state/sessionWorkspaceDetach.test.ts

@@ -1,12 +1,12 @@
 import assert from "node:assert/strict";
 import test from "node:test";
 import type { TerminalSession, Workspace } from "../../domain/models";
+import type { AIChatRecencyEntry } from "../../domain/aiSessionRecency";
 import {
   applyCloseSessionToSessions,
   closeSessionsState,
   closeSessionWorkspaceLayoutState,
   detachSessionFromWorkspaceState,
-  replaceDissolvedWorkspaceTabOrder,
   resolveActiveTabAfterCloseSession,
 } from "./sessionWorkspaceDetach";
 
@@ -14,11 +14,19 @@ const session = (id: string, workspaceId = "ws-1"): TerminalSession => ({
   id,
   hostId: id,
   hostLabel: id,
+  username: "user",
+  hostname: id,
   status: "connected",
   workspaceId,
 });
 
-const workspace = (sessionIds: string[]): Workspace => ({
+const chat = (id: string, targetId: string, updatedAt: number): AIChatRecencyEntry => ({
+  id,
+  scope: { type: "terminal", targetId },
+  updatedAt,
+});
+
+const workspace = (sessionIds: string[], overrides: Partial<Workspace> = {}): Workspace => ({
   id: "ws-1",
   title: "Workspace",
   focusedSessionId: sessionIds[0],
@@ -36,9 +44,17 @@ const workspace = (sessionIds: string[]): Workspace => ({
         })),
         sizes: sessionIds.map(() => 1),
       },
+  ...overrides,
 });
 
-test("detach dissolves the original workspace when one session remains", () => {
+const rootPaneSessionIds = (workspace: Workspace): string[] => (
+  workspace.root.type === "pane"
+    ? [workspace.root.sessionId]
+    : workspace.root.children.map((child) => child.type === "pane" ? child.sessionId : "")
+      .filter((id): id is string => Boolean(id))
+);
+
+test("detaching to one member keeps the workspace alive (#4098 phase 2)", () => {
   const result = detachSessionFromWorkspaceState({
     sessions: [session("s1"), session("s2")],
     workspaces: [workspace(["s1", "s2"])],
@@ -49,149 +65,126 @@ test("detach dissolves the original workspace when one session remains", () => {
   assert.equal(result.activeTabId, "s1");
   assert.deepEqual(result.sessions.map((s) => [s.id, s.workspaceId]), [
     ["s1", undefined],
-    ["s2", undefined],
+    // The survivor keeps its workspace binding — no orphan promotion.
+    ["s2", "ws-1"],
   ]);
-  assert.equal(result.workspaces.length, 0);
-  assert.equal(result.dissolvedWorkspaceId, "ws-1");
-  assert.deepEqual(result.replacementTabIds, ["s1", "s2"]);
+  assert.equal(result.workspaces.length, 1);
+  assert.equal(result.workspaces[0].id, "ws-1");
+  assert.deepEqual(rootPaneSessionIds(result.workspaces[0]), ["s2"]);
 });
 
-test("detach preserves the other sessions in a multi-pane workspace", () => {
+test("detaching the last member keeps the workspace with an empty root (#4098 phase 2)", () => {
   const result = detachSessionFromWorkspaceState({
-    sessions: [session("s1"), session("s2"), session("s3")],
-    workspaces: [workspace(["s1", "s2", "s3"])],
-    sessionId: "s2",
+    sessions: [session("s1")],
+    workspaces: [workspace(["s1"])],
+    sessionId: "s1",
   });
 
   assert.equal(result.changed, true);
-  assert.deepEqual(result.sessions.map((s) => [s.id, s.workspaceId]), [
-    ["s1", "ws-1"],
-    ["s2", undefined],
-    ["s3", "ws-1"],
-  ]);
-  assert.deepEqual(result.workspaces[0].focusSessionOrder, ["s1", "s3"]);
-  assert.equal(result.workspaces[0].focusedSessionId, "s1");
+  assert.equal(result.workspaces.length, 1);
+  assert.equal(result.workspaces[0].id, "ws-1");
+  assert.equal(result.workspaces[0].root.type, "split");
   assert.deepEqual(
-    result.workspaces[0].root.type === "split"
-      ? result.workspaces[0].root.children.map((child) => child.type === "pane" ? child.sessionId : null)
-      : [],
-    ["s1", "s3"],
+    result.workspaces[0].root.type === "split" ? result.workspaces[0].root.children : null,
+    [],
   );
+  assert.equal(result.workspaces[0].focusedSessionId, undefined);
 });
 
-test("dissolved workspace replacement preserves its tab position", () => {
-  assert.deepEqual(
-    replaceDissolvedWorkspaceTabOrder(["log-1", "ws-1", "session-3"], "ws-1", ["s1", "s2"]),
-    ["log-1", "s1", "s2", "session-3"],
-  );
+test("closing one member keeps the workspace and its surviving member bound (#4098 phase 2)", () => {
+  const result = closeSessionsState({
+    sessions: [session("s1"), session("s2")],
+    workspaces: [workspace(["s1", "s2"])],
+    sessionIds: ["s1"],
+    currentActiveTabId: "ws-1",
+    tabOrder: ["ws-1"],
+  });
+
+  assert.equal(result.workspaces.length, 1);
+  assert.equal(result.workspaces[0].id, "ws-1");
+  assert.deepEqual(result.sessions.map((s) => [s.id, s.workspaceId]), [["s2", "ws-1"]]);
+  // The workspace tab is still live, so the active tab does not move.
+  assert.equal(result.activeTabId, undefined);
 });
 
-test("dissolved workspace replacement removes duplicate replacement ids", () => {
-  assert.deepEqual(
-    replaceDissolvedWorkspaceTabOrder(["s1", "ws-1", "session-3"], "ws-1", ["s1", "s2"]),
-    ["s1", "s2", "session-3"],
-  );
-});
-
-test("dissolved workspace replacement is idempotent", () => {
-  const once = replaceDissolvedWorkspaceTabOrder(["log-1", "ws-1", "session-3"], "ws-1", ["s1", "s2"]);
-
-  assert.deepEqual(
-    replaceDissolvedWorkspaceTabOrder(once, "ws-1", ["s1", "s2"]),
-    once,
-  );
-});
-
-test("single remaining session preserves dissolved workspace tab position", () => {
-  assert.deepEqual(
-    replaceDissolvedWorkspaceTabOrder(["log-1", "ws-1", "session-3"], "ws-1", ["s2"]),
-    ["log-1", "s2", "session-3"],
-  );
-});
-
-test("closing a workspace session dissolves the workspace when one terminal remains", () => {
-  const result = closeSessionWorkspaceLayoutState([workspace(["s1", "s2"])], "ws-1", "s1");
-
-  assert.equal(result.dissolvedWorkspaceId, "ws-1");
-  assert.equal(result.lastRemainingSessionId, "s2");
-  assert.deepEqual(result.workspaces, []);
-  assert.deepEqual(
-    replaceDissolvedWorkspaceTabOrder(
-      ["log-1", result.dissolvedWorkspaceId!, "session-3"],
-      result.dissolvedWorkspaceId,
-      result.lastRemainingSessionId ? [result.lastRemainingSessionId] : undefined,
-    ),
-    ["log-1", "s2", "session-3"],
-  );
-});
-
-test("closing the focused session hands focus to a remaining session (#3046)", () => {
+test("member loss hands focus to the most-recently-active survivor, not sessions[0]", () => {
   const result = closeSessionWorkspaceLayoutState(
-    [workspace(["s1", "s2", "s3", "s4"])],
+    [workspace(["s1", "s2", "s3"])],
     "ws-1",
     "s1",
+    [chat("chat-s2", "s2", 4), chat("chat-s3", "s3", 9)],
   );
 
   assert.equal(result.workspaces.length, 1);
-  assert.equal(result.workspaces[0].focusedSessionId, "s2");
-  assert.deepEqual(result.workspaces[0].focusSessionOrder, ["s2", "s3", "s4"]);
+  // remainingSessionIds[0] is s2, but s3's chat is the most recent.
+  assert.equal(result.workspaces[0].focusedSessionId, "s3");
 });
 
-test("closing a non-focused session keeps the focused session", () => {
+test("reordering focus order does not change the survivor retarget", () => {
   const result = closeSessionWorkspaceLayoutState(
-    [workspace(["s1", "s2", "s3", "s4"])],
+    [workspace(["s1", "s2", "s3"], { focusSessionOrder: ["s3", "s2", "s1"] })],
+    "ws-1",
+    "s1",
+    [chat("chat-s2", "s2", 4), chat("chat-s3", "s3", 9)],
+  );
+
+  assert.equal(result.workspaces[0].focusedSessionId, "s3");
+});
+
+test("closing a non-focused member keeps the focused member", () => {
+  const result = closeSessionWorkspaceLayoutState(
+    [workspace(["s1", "s2", "s3"])],
     "ws-1",
     "s3",
   );
 
   assert.equal(result.workspaces.length, 1);
   assert.equal(result.workspaces[0].focusedSessionId, "s1");
-  assert.deepEqual(result.workspaces[0].focusSessionOrder, ["s1", "s2", "s4"]);
+  assert.deepEqual(result.workspaces[0].focusSessionOrder, ["s1", "s2"]);
 });
 
-test("closing one split pane keeps the other terminal as an orphan tab", () => {
-  const layoutResult = closeSessionWorkspaceLayoutState(
+test("with no AI recency signal focus stays on a surviving terminal", () => {
+  const result = closeSessionWorkspaceLayoutState(
     [workspace(["s1", "s2"])],
     "ws-1",
     "s1",
   );
-  const nextSessions = applyCloseSessionToSessions(
-    [session("s1"), session("s2")],
-    "s1",
-    layoutResult,
-  );
 
-  assert.deepEqual(nextSessions.map((s) => [s.id, s.workspaceId]), [
-    ["s2", undefined],
-  ]);
-  assert.equal(
-    resolveActiveTabAfterCloseSession({
-      currentActiveTabId: "ws-1",
-      closedSessionId: "s1",
-      workspaceId: "ws-1",
-      layoutResult,
-      remainingSessions: nextSessions,
-      preferredTabId: "s-outside",
-    }),
-    "s2",
-  );
+  assert.equal(result.workspaces.length, 1);
+  assert.equal(result.workspaces[0].focusedSessionId, "s2");
 });
 
-test("closing the last workspace session does not invent a surviving terminal", () => {
+test("closing ALL members keeps the workspace alive with an empty root (#4098 phase 2)", () => {
+  const result = closeSessionsState({
+    sessions: [session("s1"), session("s2")],
+    workspaces: [workspace(["s1", "s2"])],
+    sessionIds: ["s1", "s2"],
+    currentActiveTabId: "ws-1",
+    tabOrder: ["ws-1"],
+  });
+
+  assert.deepEqual(result.sessions, []);
+  assert.equal(result.workspaces.length, 1);
+  assert.equal(result.workspaces[0].id, "ws-1");
+  assert.equal(result.workspaces[0].root.type, "split");
+  assert.deepEqual(
+    result.workspaces[0].root.type === "split" ? result.workspaces[0].root.children : null,
+    [],
+  );
+  // The workspace tab survives, so the active tab is left alone.
+  assert.equal(result.activeTabId, undefined);
+});
+
+test("closing a solo workspace member still replaces the closed tab's activity via fallbacks", () => {
   const layoutResult = closeSessionWorkspaceLayoutState(
     [workspace(["s1"])],
     "ws-1",
     "s1",
   );
-  const nextSessions = applyCloseSessionToSessions(
-    [session("s1")],
-    "s1",
-    layoutResult,
-  );
+  const nextSessions = applyCloseSessionToSessions([session("s1")], "s1");
 
   assert.deepEqual(nextSessions, []);
-  assert.equal(layoutResult.removedWorkspaceId, "ws-1");
-  assert.equal(layoutResult.lastRemainingSessionId, undefined);
+  // The workspace tab survives, so an active workspace tab needs no fallback.
   assert.equal(
     resolveActiveTabAfterCloseSession({
       currentActiveTabId: "ws-1",
@@ -200,25 +193,7 @@ test("closing the last workspace session does not invent a surviving terminal",
       layoutResult,
       remainingSessions: nextSessions,
     }),
-    "vault",
-  );
-});
-
-test("closing the last visible solo tab does not fall back to a hidden MCP session", () => {
-  const visibleSession: TerminalSession = { ...session("s1", undefined) };
-  const hiddenSession: TerminalSession = { ...session("s2", undefined), hiddenFromTabs: true };
-  const layoutResult = closeSessionWorkspaceLayoutState([], undefined, "s1");
-  const remainingSessions = [hiddenSession];
-
-  assert.equal(
-    resolveActiveTabAfterCloseSession({
-      currentActiveTabId: visibleSession.id,
-      closedSessionId: "s1",
-      workspaceId: undefined,
-      layoutResult,
-      remainingSessions,
-    }),
-    "vault",
+    null,
   );
 });
 

application/state/sessionWorkspaceDetach.ts

@@ -1,20 +1,17 @@
 import type { TerminalSession, Workspace } from "../../domain/models";
-import { collectSessionIds, pruneWorkspaceNode } from "../../domain/workspace";
+import type { AIChatRecencyEntry } from "../../domain/aiSessionRecency";
+import { resolveMostRecentlyActiveMemberTerminalId } from "../../domain/aiSessionRecency";
+import { collectSessionIds, createEmptyWorkspaceRoot, pruneWorkspaceNode } from "../../domain/workspace";
 
 export type DetachSessionFromWorkspaceStateResult = {
   changed: boolean;
   sessions: TerminalSession[];
   workspaces: Workspace[];
   activeTabId?: string;
-  dissolvedWorkspaceId?: string;
-  replacementTabIds?: string[];
 };
 
 export type CloseSessionWorkspaceLayoutResult = {
   workspaces: Workspace[];
-  removedWorkspaceId?: string;
-  dissolvedWorkspaceId?: string;
-  lastRemainingSessionId?: string;
 };
 
 export type CloseSessionsStateResult = {
@@ -28,82 +25,65 @@ type DetachSessionFromWorkspaceStateOptions = {
   sessions: TerminalSession[];
   workspaces: Workspace[];
   sessionId: string;
+  /**
+   * AI chat store snapshot used to rank surviving members by chat recency.
+   * Without a recency signal, terminal display still needs a live member.
+   */
+  aiSessions?: readonly AIChatRecencyEntry[];
 };
 
-export function replaceDissolvedWorkspaceTabOrder(
-  tabOrder: readonly string[],
-  workspaceId: string | undefined,
-  replacementTabIds: readonly string[] | undefined,
-): string[] {
-  if (!workspaceId || !replacementTabIds?.length) return [...tabOrder];
-
-  const uniqueReplacementIds = replacementTabIds.filter((tabId, index, list) => (
-    tabId && list.indexOf(tabId) === index
-  ));
-  if (uniqueReplacementIds.length === 0) return [...tabOrder];
-
-  if (!tabOrder.includes(workspaceId)) {
-    const hasAllReplacementIds = uniqueReplacementIds.every((tabId) => tabOrder.includes(tabId));
-    return hasAllReplacementIds ? [...tabOrder] : [
-      ...tabOrder,
-      ...uniqueReplacementIds.filter((tabId) => !tabOrder.includes(tabId)),
-    ];
+/**
+ * Resolve the member that should receive focus (or an anchor retarget) after a
+ * member loss. Prefers the AI-chat recency winner; falls back to the still-
+ * valid preferred (focused) member because that is explicit user intent, and
+ * falls back to a surviving pane so focus mode never hides all terminals.
+ */
+const resolveSurvivingFocusMemberId = (
+  remainingSessionIds: readonly string[],
+  previousFocusedSessionId: string | undefined,
+  aiSessions: readonly AIChatRecencyEntry[] | undefined,
+): string | undefined => {
+  if (previousFocusedSessionId && remainingSessionIds.includes(previousFocusedSessionId)) {
+    return previousFocusedSessionId;
   }
-
-  const replacementIdSet = new Set(uniqueReplacementIds);
-  let inserted = false;
-  const nextOrder: string[] = [];
-
-  for (const tabId of tabOrder) {
-    if (tabId === workspaceId) {
-      if (!inserted) {
-        nextOrder.push(...uniqueReplacementIds);
-        inserted = true;
-      }
-      continue;
-    }
-    if (!replacementIdSet.has(tabId)) {
-      nextOrder.push(tabId);
-    }
-  }
-
-  return nextOrder;
-}
+  return resolveMostRecentlyActiveMemberTerminalId({
+    memberTerminalIds: remainingSessionIds,
+    aiSessions,
+  }) ?? remainingSessionIds[0];
+};
 
 export function closeSessionWorkspaceLayoutState(
   workspaces: readonly Workspace[],
   workspaceId: string | undefined,
   sessionId: string,
+  aiSessions?: readonly AIChatRecencyEntry[],
 ): CloseSessionWorkspaceLayoutResult {
   if (!workspaceId) return { workspaces: [...workspaces] };
 
-  let removedWorkspaceId: string | undefined;
-  let dissolvedWorkspaceId: string | undefined;
-  let lastRemainingSessionId: string | undefined;
   const nextWorkspaces = workspaces
     .map((workspace) => {
       if (workspace.id !== workspaceId) return workspace;
       const prunedRoot = pruneWorkspaceNode(workspace.root, sessionId);
       if (!prunedRoot) {
-        removedWorkspaceId = workspace.id;
-        return null;
+        // Issue #4098 phase 2: the last member closed, but the workspace is a
+        // first-class entity — it survives with an empty root so its id (and
+        // the AI chats anchored to it) survive restart and member churn.
+        return {
+          ...workspace,
+          root: createEmptyWorkspaceRoot(),
+          focusedSessionId: undefined,
+          focusSessionOrder: [],
+        };
       }
 
       const remainingSessionIds = collectSessionIds(prunedRoot);
-      if (remainingSessionIds.length === 1) {
-        dissolvedWorkspaceId = workspace.id;
-        lastRemainingSessionId = remainingSessionIds[0];
-        return null;
-      }
-
-      // Closing the focused session must hand focus to a remaining one, or a
-      // focus-mode workspace is left with a dangling focusedSessionId: no pane
-      // qualifies as visible and the continuously rendered hidden panes all
-      // paint on top of each other (#3046).
-      const nextFocusedSessionId =
-        workspace.focusedSessionId && !remainingSessionIds.includes(workspace.focusedSessionId)
-          ? remainingSessionIds[0]
-          : workspace.focusedSessionId;
+      // Closing the focused session hands focus to the most-recently-active
+      // surviving member when AI chat recency is available.
+      const nextFocusedSessionId = resolveSurvivingFocusMemberId(
+        remainingSessionIds,
+        workspace.focusedSessionId,
+        aiSessions,
+      );
       const nextFocusSessionOrder = workspace.focusSessionOrder?.filter(
         (candidateId) => remainingSessionIds.includes(candidateId),
       );
@@ -114,36 +94,23 @@ export function closeSessionWorkspaceLayoutState(
         focusedSessionId: nextFocusedSessionId,
         focusSessionOrder: nextFocusSessionOrder,
       };
-    })
-    .filter((workspace): workspace is Workspace => Boolean(workspace));
+    });
 
   return {
     workspaces: nextWorkspaces,
-    removedWorkspaceId,
-    dissolvedWorkspaceId,
-    lastRemainingSessionId,
   };
 }
 
 /**
  * Apply a close-session action to the session list using the layout result.
- * When a 2-pane workspace dissolves to one terminal, that remaining session
- * must become an orphan tab — not stay bound to a deleted workspaceId.
+ * Since issue #4098 phase 2 workspaces survive member loss (no dissolve), the
+ * remaining members keep their workspace binding.
  */
 export function applyCloseSessionToSessions(
   sessions: readonly TerminalSession[],
   sessionId: string,
-  layoutResult: Pick<CloseSessionWorkspaceLayoutResult, "lastRemainingSessionId">,
 ): TerminalSession[] {
-  const remaining = sessions.filter((session) => session.id !== sessionId);
-  const lastRemainingSessionId = layoutResult.lastRemainingSessionId;
-  if (!lastRemainingSessionId) return remaining;
-
-  return remaining.map((session) => (
-    session.id === lastRemainingSessionId
-      ? { ...session, workspaceId: undefined }
-      : session
-  ));
+  return sessions.filter((session) => session.id !== sessionId);
 }
 
 export function isPreferredTabAvailableAfterClose(
@@ -161,12 +128,6 @@ export function isPreferredTabAvailableAfterClose(
 } {
   const { preferredTabId, closedSessionId, layoutResult, remainingSessions } = input;
   if (!preferredTabId || preferredTabId === closedSessionId) return false;
-  if (
-    preferredTabId === layoutResult.dissolvedWorkspaceId
-    || preferredTabId === layoutResult.removedWorkspaceId
-  ) {
-    return false;
-  }
   if (preferredTabId === "vault" || preferredTabId === "sftp") return true;
   if (layoutResult.workspaces.some((workspace) => workspace.id === preferredTabId)) return true;
   return remainingSessions.some((session) => (
@@ -179,7 +140,6 @@ export function isPreferredTabAvailableAfterClose(
 export function resolveActiveTabAfterCloseSession({
   currentActiveTabId,
   closedSessionId,
-  workspaceId,
   layoutResult,
   remainingSessions,
   preferredTabId,
@@ -202,18 +162,14 @@ export function resolveActiveTabAfterCloseSession({
   const preferredFallback = isPreferredTabAvailableAfterClose(preferredInput)
     ? preferredInput.preferredTabId
     : undefined;
-  const fallback = layoutResult.lastRemainingSessionId
-    ?? preferredFallback
+  const fallback = preferredFallback
     ?? fallbackWorkspace?.id
     ?? fallbackSolo?.id
     ?? "vault";
 
-  if (
-    currentActiveTabId === closedSessionId
-    || (layoutResult.dissolvedWorkspaceId && currentActiveTabId === layoutResult.dissolvedWorkspaceId)
-    || (layoutResult.removedWorkspaceId && currentActiveTabId === layoutResult.removedWorkspaceId)
-    || (workspaceId && currentActiveTabId === workspaceId && !layoutResult.workspaces.some((ws) => ws.id === workspaceId))
-  ) {
+  // Workspaces survive member loss (#4098 phase 2), so only a closed session
+  // tab that was active needs a replacement.
+  if (currentActiveTabId === closedSessionId) {
     return fallback;
   }
 
@@ -227,6 +183,7 @@ export function closeSessionsState({
   currentActiveTabId,
   preferredTabId,
   tabOrder,
+  aiSessions,
 }: {
   sessions: readonly TerminalSession[];
   workspaces: readonly Workspace[];
@@ -234,6 +191,7 @@ export function closeSessionsState({
   currentActiveTabId: string | null;
   preferredTabId?: string | null;
   tabOrder: readonly string[];
+  aiSessions?: readonly AIChatRecencyEntry[];
 }): CloseSessionsStateResult {
   let nextSessions = [...sessions];
   let nextWorkspaces = [...workspaces];
@@ -250,17 +208,10 @@ export function closeSessionsState({
       nextWorkspaces,
       workspaceId,
       sessionId,
+      aiSessions,
     );
     nextWorkspaces = layoutResult.workspaces;
-    nextSessions = applyCloseSessionToSessions(nextSessions, sessionId, layoutResult);
-
-    if (layoutResult.dissolvedWorkspaceId && layoutResult.lastRemainingSessionId) {
-      nextTabOrder = replaceDissolvedWorkspaceTabOrder(
-        nextTabOrder,
-        layoutResult.dissolvedWorkspaceId,
-        [layoutResult.lastRemainingSessionId],
-      );
-    }
+    nextSessions = applyCloseSessionToSessions(nextSessions, sessionId);
 
     const activeTabAfterClose = resolveActiveTabAfterCloseSession({
       currentActiveTabId: nextActiveTabId,
@@ -288,6 +239,7 @@ export function detachSessionFromWorkspaceState({
   sessions,
   workspaces,
   sessionId,
+  aiSessions,
 }: DetachSessionFromWorkspaceStateOptions): DetachSessionFromWorkspaceStateResult {
   const session = sessions.find((candidate) => candidate.id === sessionId);
   if (!session?.workspaceId) {
@@ -301,40 +253,36 @@ export function detachSessionFromWorkspaceState({
   }
 
   const prunedRoot = pruneWorkspaceNode(targetWorkspace.root, sessionId);
-  let nextSessions = sessions.map((candidate) => (
+  const nextSessions = sessions.map((candidate) => (
     candidate.id === sessionId ? { ...candidate, workspaceId: undefined } : candidate
   ));
 
   if (!prunedRoot) {
+    // Last member dragged out: the workspace entity survives with an empty
+    // root (#4098 phase 2) so its id and anchored AI chats stay stable.
     return {
       changed: true,
       sessions: nextSessions,
-      workspaces: workspaces.filter((workspace) => workspace.id !== workspaceId),
+      workspaces: workspaces.map((workspace) => (
+        workspace.id === workspaceId
+          ? {
+              ...workspace,
+              root: createEmptyWorkspaceRoot(),
+              focusedSessionId: undefined,
+              focusSessionOrder: [],
+            }
+          : workspace
+      )),
       activeTabId: sessionId,
-      dissolvedWorkspaceId: workspaceId,
-      replacementTabIds: [sessionId],
     };
   }
 
   const remainingSessionIds = collectSessionIds(prunedRoot);
-  if (remainingSessionIds.length === 1) {
-    nextSessions = nextSessions.map((candidate) => (
-      candidate.id === remainingSessionIds[0] ? { ...candidate, workspaceId: undefined } : candidate
-    ));
-
-    return {
-      changed: true,
-      sessions: nextSessions,
-      workspaces: workspaces.filter((workspace) => workspace.id !== workspaceId),
-      activeTabId: sessionId,
-      dissolvedWorkspaceId: workspaceId,
-      replacementTabIds: [sessionId, ...remainingSessionIds],
-    };
-  }
-
-  const nextFocusedSessionId = remainingSessionIds.includes(targetWorkspace.focusedSessionId)
-    ? targetWorkspace.focusedSessionId
-    : remainingSessionIds[0];
+  const nextFocusedSessionId = resolveSurvivingFocusMemberId(
+    remainingSessionIds,
+    targetWorkspace.focusedSessionId,
+    aiSessions,
+  );
   const nextFocusSessionOrder = (targetWorkspace.focusSessionOrder ?? [])
     .filter((candidateId, index, list) => (
       candidateId !== sessionId &&

application/state/sftp/createSftpArchive.test.ts

@@ -0,0 +1,89 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import type { SftpPane } from "./types";
+import type { SftpArchiveCreationResult } from "../../../domain/sftpArchiveCreation";
+import { createSftpArchiveForPane } from "./createSftpArchive.ts";
+
+function setup() {
+  let pane = {
+    id: "pane-a", connection: { id: "connection-a", isLocal: false }, filenameEncoding: "gb18030",
+  } as SftpPane;
+  const calls: unknown[][] = [];
+  const refreshes: string[] = [];
+  const params = {
+    getPane: () => pane,
+    target: { paneId: "pane-a", connectionId: "connection-a" },
+    options: { directory: "/srv", paths: ["中文", "logs"], archiveName: "backup.zip", format: "zip" as const },
+    getSftpIdForConnection: (id: string) => id === "connection-a" ? "sftp-a" : undefined,
+    bridge: {
+      createSftpArchive: async (...args: unknown[]): Promise<SftpArchiveCreationResult> => {
+        calls.push(args);
+        return { success: true };
+      },
+    },
+    refresh: async (id: string) => { refreshes.push(id); },
+    t: (key: string) => key,
+  };
+  return { params, calls, refreshes, setPane: (value: SftpPane) => { pane = value; } };
+}
+
+test("archive creation passes selected paths and encoding to the captured remote session", async () => {
+  const { params, calls, refreshes } = setup();
+  assert.deepEqual(await createSftpArchiveForPane(params), { success: true });
+  assert.deepEqual(calls, [["sftp-a", params.options, "gb18030"]]);
+  assert.deepEqual(refreshes, ["pane-a"]);
+});
+
+test("a switched or disconnected pane cannot compress files on another host", async () => {
+  for (const change of [
+    { id: "pane-b" },
+    { connection: { id: "connection-b", isLocal: false } },
+    { connection: null },
+  ]) {
+    const { params, calls, setPane } = setup();
+    setPane({ ...params.getPane(), ...change } as SftpPane);
+    await assert.rejects(createSftpArchiveForPane(params), /connectionChanged/);
+    assert.equal(calls.length, 0);
+  }
+});
+
+test("archive creation requires a remote session and a supported bridge", async () => {
+  const { params, calls, setPane } = setup();
+  await assert.rejects(createSftpArchiveForPane({ ...params, bridge: undefined }), /unavailable/);
+  await assert.rejects(createSftpArchiveForPane({ ...params, getSftpIdForConnection: () => undefined }), /unavailable/);
+  setPane({ ...params.getPane(), connection: { id: "connection-a", isLocal: true } } as SftpPane);
+  await assert.rejects(createSftpArchiveForPane(params), /unavailable/);
+  assert.equal(calls.length, 0);
+});
+
+test("existing archives are returned for confirmation without retry or refresh", async () => {
+  const { params, refreshes } = setup();
+  const conflict = { success: false, code: "EEXIST", error: "Already exists" };
+  params.bridge.createSftpArchive = async () => conflict;
+  assert.equal(await createSftpArchiveForPane(params), conflict);
+  assert.deepEqual(refreshes, []);
+});
+
+test("finishing after a tab switch does not refresh the new connection", async () => {
+  const { params, refreshes, setPane } = setup();
+  params.bridge.createSftpArchive = async () => {
+    setPane({ ...params.getPane(), id: "pane-b" } as SftpPane);
+    return { success: true };
+  };
+  assert.deepEqual(await createSftpArchiveForPane(params), { success: true });
+  assert.deepEqual(refreshes, []);
+});
+
+test("a failed operation is not refreshed or converted to success", async () => {
+  const { params, refreshes } = setup();
+  params.bridge.createSftpArchive = async () => { throw new Error("zip is not installed"); };
+  await assert.rejects(createSftpArchiveForPane(params), /zip is not installed/);
+  assert.deepEqual(refreshes, []);
+});
+
+test("a listing error after publication does not invite a second archive creation", async () => {
+  const { params, calls } = setup();
+  params.refresh = async () => { throw new Error("Disconnected after publication"); };
+  assert.deepEqual(await createSftpArchiveForPane(params), { success: true });
+  assert.equal(calls.length, 1);
+});

application/state/sftp/createSftpArchive.ts

@@ -0,0 +1,46 @@
+import type {
+  SftpArchiveCreationOptions,
+  SftpArchiveCreationResult,
+  SftpArchiveCreationTarget,
+} from "../../../domain/sftpArchiveCreation";
+import type { SftpPane } from "./types";
+import { logger } from "../../../lib/logger";
+
+interface CreateSftpArchiveParams {
+  getPane: () => Pick<SftpPane, "id" | "connection" | "filenameEncoding">;
+  target: SftpArchiveCreationTarget;
+  options: SftpArchiveCreationOptions;
+  bridge: Pick<NetcattyBridge, "createSftpArchive"> | undefined;
+  getSftpIdForConnection?: (connectionId: string) => string | undefined;
+  refresh: (paneId: string) => Promise<void>;
+  t: (key: string) => string;
+}
+
+/** Bind the selected files to the pane/connection that opened the dialog. */
+export async function createSftpArchiveForPane({
+  getPane, target, options, bridge, getSftpIdForConnection, refresh, t,
+}: CreateSftpArchiveParams): Promise<SftpArchiveCreationResult> {
+  const pane = getPane();
+  if (pane.id !== target.paneId || pane.connection?.id !== target.connectionId) {
+    throw new Error(t("sftp.archive.connectionChanged"));
+  }
+  const sftpId = getSftpIdForConnection?.(target.connectionId);
+  if (pane.connection.isLocal || !sftpId || !bridge?.createSftpArchive) {
+    throw new Error(t("sftp.archive.unavailable"));
+  }
+  const result = await bridge.createSftpArchive(sftpId, options, pane.filenameEncoding);
+  if (!result.success) return result;
+
+  // A tab switch during compression must not refresh an unrelated connection.
+  const current = getPane();
+  if (current.id === target.paneId && current.connection?.id === target.connectionId) {
+    try {
+      await refresh(target.paneId);
+    } catch (error) {
+      // The archive has already been published. A listing failure must not
+      // invite the user to repeat a successful operation (or overwrite it).
+      logger.warn("[SFTP] Archive created but directory refresh failed:", error);
+    }
+  }
+  return result;
+}

application/state/sftp/duplicateEntries.test.ts

@@ -0,0 +1,131 @@
+/** @test issue #4132 — a one-click duplicate copies next to the source without a conflict prompt */
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import test from "node:test";
+import React from "react";
+import { act, create, type ReactTestRenderer } from "react-test-renderer";
+import { useSftpTransfers } from "./useSftpTransfers";
+import { createEmptyPane } from "./types";
+import { sftpTransferCenterStore } from "../sftpTransferCenterStore";
+
+test("duplicate transfers resolve same-name conflicts to (copy) without prompting", async () => {
+  const dir = await fs.mkdtemp(path.join(process.cwd(), ".duplicate-entries-"));
+  const ownerId = `duplicate-entries-${crypto.randomUUID()}`;
+  const previousWindow = globalThis.window;
+  const previousStorage = globalThis.localStorage;
+  const globals = globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean };
+  const previousAct = globals.IS_REACT_ACT_ENVIRONMENT;
+  globals.IS_REACT_ACT_ENVIRONMENT = true;
+  let renderer: ReactTestRenderer | undefined;
+  let ops!: ReturnType<typeof useSftpTransfers>;
+  // A duplicate has to cover both files and folders: the conflict type key
+  // differs between the two and the seeded defaults must match both.
+  const fileNames = ["report.txt"];
+  const folderNames = ["photos"];
+  for (const name of fileNames) {
+    await fs.writeFile(path.join(dir, name), "original data");
+  }
+  for (const name of folderNames) {
+    await fs.mkdir(path.join(dir, name));
+    await fs.writeFile(path.join(dir, name, "nested.txt"), "nested data");
+  }
+  const pane = createEmptyPane("duplicate-pane");
+  pane.connection = { id: ownerId, isLocal: true, currentPath: dir, status: "connected" } as NonNullable<typeof pane.connection>;
+  const statPath = async (value: string) => {
+    try {
+      const stat = await fs.lstat(value);
+      return { type: stat.isSymbolicLink() ? "symlink" : stat.isDirectory() ? "directory" : "file", size: stat.size, lastModified: stat.mtimeMs };
+    } catch {
+      return null;
+    }
+  };
+  (globalThis as { window?: unknown }).window = { requestAnimationFrame: (callback: () => void) => setTimeout(callback, 0), cancelAnimationFrame: clearTimeout, netcatty: {
+    realpathLocal: fs.realpath, statLocal: statPath, lstatLocal: statPath,
+    mkdirLocal: async (value: string) => { await fs.mkdir(value, { recursive: true }); },
+    deleteLocalFile: async (value: string) => { await fs.rm(value, { recursive: true, force: true }); },
+    renameLocalFile: async (source: string, target: string) => { await fs.rename(source, target); },
+    startStreamTransfer: async (options: { sourcePath: string; targetPath: string; transferId: string }) => {
+      await fs.copyFile(options.sourcePath, options.targetPath);
+      sftpTransferCenterStore.ingestBackgroundEvent({ type: "completed", transferId: options.transferId, transferred: 13, totalBytes: 13, lifecycleEpoch: 0 });
+      return {};
+    },
+  } };
+  (globalThis as { localStorage?: unknown }).localStorage = { getItem: () => null, setItem: () => undefined, removeItem: () => undefined };
+  function Probe() {
+    ops = useSftpTransfers({
+      ownerId, getActivePane: () => pane, getPaneByConnectionId: () => pane, getTabByConnectionId: () => ({ side: "left", tabId: pane.id, pane }),
+      updateTab: () => undefined, refresh: async () => undefined,
+      clearCacheForConnection: () => undefined, handleSessionError: () => undefined,
+      sftpSessionsRef: { current: new Map() }, connectionCacheKeyMapRef: { current: new Map() },
+      listRemoteFiles: async () => [],
+      listLocalFiles: async (value: string) => Promise.all((await fs.readdir(value)).map(async name => {
+        const stat = await fs.lstat(path.join(value, name));
+        return { name, type: stat.isSymbolicLink() ? "symlink" as const : stat.isDirectory() ? "directory" as const : "file" as const, size: stat.size, sizeFormatted: "", lastModified: stat.mtimeMs, lastModifiedFormatted: "" };
+      })),
+    });
+    return null;
+  }
+  const waitForSettledRoots = async (expected: number) => {
+    await act(async () => {
+      const deadline = Date.now() + 5000;
+      while (Date.now() < deadline) {
+        const roots = sftpTransferCenterStore.getOwnerTasks(ownerId).filter(row => !row.parentTaskId);
+        if (roots.length === expected && roots.every(row => ["completed", "failed"].includes(row.status))) return;
+        await new Promise(resolve => setTimeout(resolve, 20));
+      }
+    });
+  };
+  try {
+    await act(async () => { renderer = create(React.createElement(Probe)); });
+    const sources = [...fileNames, ...folderNames].map(name => ({ name, isDirectory: folderNames.includes(name) }));
+    await act(async () => {
+      await ops.startTransfer(sources, "left", "left", { sourcePath: dir, targetPath: dir, duplicate: true });
+    });
+    // The duplicate option must resolve conflicts by itself; a prompt here
+    // would defeat the one-click action the issue asks for.
+    assert.deepEqual(ops.conflicts, []);
+    await waitForSettledRoots(sources.length);
+    const roots = sftpTransferCenterStore.getOwnerTasks(ownerId).filter(row => !row.parentTaskId);
+    assert.equal(roots.length, sources.length, JSON.stringify(roots.map(row => row.fileName)));
+    assert.ok(roots.every(row => row.status === "completed"), JSON.stringify(roots.map(row => ({ status: row.status, error: row.error }))));
+    for (const name of fileNames) {
+      assert.equal(await fs.readFile(path.join(dir, name), "utf8"), "original data");
+    }
+    assert.equal(await fs.readFile(path.join(dir, "report (copy).txt"), "utf8"), "original data");
+    assert.equal(await fs.readFile(path.join(dir, "photos (copy)", "nested.txt"), "utf8"), "nested data");
+
+    // A second duplicate must pick the next free name instead of colliding
+    // with the copy created by the first run.
+    await act(async () => {
+      await ops.startTransfer(sources, "left", "left", { sourcePath: dir, targetPath: dir, duplicate: true });
+    });
+    assert.deepEqual(ops.conflicts, []);
+    await waitForSettledRoots(sources.length * 2);
+    assert.equal(await fs.readFile(path.join(dir, "report (copy 2).txt"), "utf8"), "original data");
+    assert.equal(await fs.readFile(path.join(dir, "photos (copy 2)", "nested.txt"), "utf8"), "nested data");
+
+    // The tree's ".." navigation row must never be duplicated: it would copy
+    // an ancestor into itself.
+    const tasksBefore = sftpTransferCenterStore.getOwnerTasks(ownerId).length;
+    let navigationResults: unknown;
+    await act(async () => {
+      navigationResults = await ops.startTransfer(
+        [{ name: "..", isDirectory: true }],
+        "left",
+        "left",
+        { sourcePath: dir, targetPath: dir, duplicate: true },
+      );
+    });
+    assert.deepEqual(navigationResults, []);
+    assert.equal(sftpTransferCenterStore.getOwnerTasks(ownerId).length, tasksBefore);
+    assert.deepEqual(ops.conflicts, []);
+  } finally {
+    await act(async () => { renderer?.unmount(); });
+    for (const row of sftpTransferCenterStore.getOwnerTasks(ownerId)) sftpTransferCenterStore.dismiss(row.id);
+    (globalThis as { window?: unknown }).window = previousWindow;
+    (globalThis as { localStorage?: unknown }).localStorage = previousStorage;
+    globals.IS_REACT_ACT_ENVIRONMENT = previousAct;
+    await fs.rm(dir, { recursive: true, force: true });
+  }
+});

application/state/sftp/duplicateInflightNaming.test.ts

@@ -0,0 +1,109 @@
+/** @test issue #4132 — a duplicate must not reuse a destination an earlier copy still holds */
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import test from "node:test";
+import React from "react";
+import { act, create, type ReactTestRenderer } from "react-test-renderer";
+import { useSftpTransfers } from "./useSftpTransfers";
+import { createEmptyPane } from "./types";
+import { sftpTransferCenterStore } from "../sftpTransferCenterStore";
+
+test("duplicate names around a destination an in-flight copy has not created yet", async () => {
+  const dir = await fs.mkdtemp(path.join(process.cwd(), ".duplicate-inflight-"));
+  const ownerId = `duplicate-inflight-${crypto.randomUUID()}`;
+  const previousWindow = globalThis.window;
+  const previousStorage = globalThis.localStorage;
+  const globals = globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean };
+  const previousAct = globals.IS_REACT_ACT_ENVIRONMENT;
+  globals.IS_REACT_ACT_ENVIRONMENT = true;
+  let renderer: ReactTestRenderer | undefined;
+  let ops!: ReturnType<typeof useSftpTransfers>;
+  let releaseFirst: (() => void) | undefined;
+  const firstCopyGate = new Promise<void>((resolve) => { releaseFirst = resolve; });
+  let streamStarts = 0;
+  await fs.writeFile(path.join(dir, "report.txt"), "original data");
+  const pane = createEmptyPane("duplicate-inflight-pane");
+  pane.connection = { id: ownerId, isLocal: true, currentPath: dir, status: "connected" } as NonNullable<typeof pane.connection>;
+  const statPath = async (value: string) => {
+    try {
+      const stat = await fs.lstat(value);
+      return { type: stat.isSymbolicLink() ? "symlink" : stat.isDirectory() ? "directory" : "file", size: stat.size, lastModified: stat.mtimeMs };
+    } catch {
+      return null;
+    }
+  };
+  (globalThis as { window?: unknown }).window = { requestAnimationFrame: (callback: () => void) => setTimeout(callback, 0), cancelAnimationFrame: clearTimeout, netcatty: {
+    realpathLocal: fs.realpath, statLocal: statPath, lstatLocal: statPath,
+    mkdirLocal: async (value: string) => { await fs.mkdir(value, { recursive: true }); },
+    deleteLocalFile: async (value: string) => { await fs.rm(value, { recursive: true, force: true }); },
+    renameLocalFile: async (source: string, target: string) => { await fs.rename(source, target); },
+    startStreamTransfer: async (options: { sourcePath: string; targetPath: string; transferId: string }) => {
+      streamStarts += 1;
+      // Hold the first copy before it writes its destination: the second
+      // duplicate then sees no "(copy)" on disk even though one is reserved.
+      if (streamStarts === 1) await firstCopyGate;
+      await fs.copyFile(options.sourcePath, options.targetPath);
+      sftpTransferCenterStore.ingestBackgroundEvent({ type: "completed", transferId: options.transferId, transferred: 13, totalBytes: 13, lifecycleEpoch: 0 });
+      return {};
+    },
+  } };
+  (globalThis as { localStorage?: unknown }).localStorage = { getItem: () => null, setItem: () => undefined, removeItem: () => undefined };
+  function Probe() {
+    ops = useSftpTransfers({
+      ownerId, getActivePane: () => pane, getPaneByConnectionId: () => pane, getTabByConnectionId: () => ({ side: "left", tabId: pane.id, pane }),
+      updateTab: () => undefined, refresh: async () => undefined,
+      clearCacheForConnection: () => undefined, handleSessionError: () => undefined,
+      sftpSessionsRef: { current: new Map() }, connectionCacheKeyMapRef: { current: new Map() },
+      listRemoteFiles: async () => [],
+      listLocalFiles: async (value: string) => Promise.all((await fs.readdir(value)).map(async name => {
+        const stat = await fs.lstat(path.join(value, name));
+        return { name, type: stat.isSymbolicLink() ? "symlink" as const : stat.isDirectory() ? "directory" as const : "file" as const, size: stat.size, sizeFormatted: "", lastModified: stat.mtimeMs, lastModifiedFormatted: "" };
+      })),
+    });
+    return null;
+  }
+  const sources = [{ name: "report.txt", isDirectory: false }];
+  const options = { sourcePath: dir, targetPath: dir, duplicate: true };
+  try {
+    await act(async () => { renderer = create(React.createElement(Probe)); });
+    // First duplicate starts copying and blocks before writing "(copy)".
+    let firstRun: ReturnType<typeof ops.startTransfer> | undefined;
+    await act(async () => {
+      firstRun = ops.startTransfer(sources, "left", "left", options);
+      const deadline = Date.now() + 3000;
+      while (streamStarts === 0 && Date.now() < deadline) {
+        await new Promise(resolve => setTimeout(resolve, 5));
+      }
+    });
+    assert.equal(streamStarts, 1, "the first copy should be in flight");
+
+    // Second duplicate runs while "(copy)" is still absent from the disk.
+    await act(async () => { await ops.startTransfer(sources, "left", "left", options); });
+    assert.equal(ops.conflicts.length, 0, "duplicate must not prompt for a reserved name");
+    releaseFirst?.();
+    await act(async () => { await firstRun; });
+
+    await act(async () => {
+      const deadline = Date.now() + 5000;
+      while (Date.now() < deadline) {
+        const rows = sftpTransferCenterStore.getOwnerTasks(ownerId).filter(row => !row.parentTaskId);
+        if (rows.length === 2 && rows.every(row => ["completed", "failed"].includes(row.status))) return;
+        await new Promise(resolve => setTimeout(resolve, 20));
+      }
+    });
+    const roots = sftpTransferCenterStore.getOwnerTasks(ownerId).filter(row => !row.parentTaskId);
+    assert.deepEqual(roots.map(row => row.fileName).sort(), ["report (copy 2).txt", "report (copy).txt"]);
+    assert.ok(roots.every(row => row.status === "completed"), JSON.stringify(roots.map(row => ({ status: row.status, error: row.error }))));
+    assert.equal(await fs.readFile(path.join(dir, "report (copy).txt"), "utf8"), "original data");
+    assert.equal(await fs.readFile(path.join(dir, "report (copy 2).txt"), "utf8"), "original data");
+  } finally {
+    releaseFirst?.();
+    await act(async () => { renderer?.unmount(); });
+    for (const row of sftpTransferCenterStore.getOwnerTasks(ownerId)) sftpTransferCenterStore.dismiss(row.id);
+    (globalThis as { window?: unknown }).window = previousWindow;
+    (globalThis as { localStorage?: unknown }).localStorage = previousStorage;
+    globals.IS_REACT_ACT_ENVIRONMENT = previousAct;
+    await fs.rm(dir, { recursive: true, force: true });
+  }
+});

application/state/sftp/transferConflictOps.ts

@@ -61,10 +61,11 @@ export function useSftpTransferConflictOps() {
 
   const getDuplicateTarget = useCallback(
     async (
-      task: TransferTask,
+      task: Pick<TransferTask, "fileName" | "isDirectory" | "targetPath">,
       targetPane: SftpPane,
       targetSftpId: string | null,
       targetEncoding: SftpFilenameEncoding,
+      isTargetTaken?: (targetPath: string) => boolean,
     ) => {
       const parentPath = getParentPath(task.targetPath);
       const { baseName, ext } = splitNameForDuplicate(task.fileName, task.isDirectory);
@@ -73,6 +74,9 @@ export function useSftpTransferConflictOps() {
         const suffix = index === 1 ? " (copy)" : ` (copy ${index})`;
         const fileName = `${baseName}${suffix}${ext}`;
         const targetPath = joinPath(parentPath, fileName);
+        // A queued/paused duplicate may not have created its destination yet,
+        // so the filesystem alone would hand out the same name twice.
+        if (isTargetTaken?.(targetPath)) continue;
         // Unsupported LSTAT must propagate — do not treat as a free name.
         const existing = await statTargetPath(targetPane, targetSftpId, targetPath, targetEncoding);
         if (!existing) return { fileName, targetPath };

application/state/sftp/useSftpArchiveDialog.test.ts

@@ -0,0 +1,161 @@
+import assert from "node:assert/strict";
+import test, { after } from "node:test";
+import React from "react";
+import { act, create, type ReactTestRenderer } from "react-test-renderer";
+import type { SftpArchiveCreationResult } from "../../../domain/sftpArchiveCreation";
+import { useSftpArchiveDialog } from "./useSftpArchiveDialog";
+
+const environment = globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean };
+const previous = environment.IS_REACT_ACT_ENVIRONMENT;
+environment.IS_REACT_ACT_ENVIRONMENT = true;
+after(() => { environment.IS_REACT_ACT_ENVIRONMENT = previous; });
+
+type Params = Parameters<typeof useSftpArchiveDialog>[0];
+
+async function mount(overrides: Partial<Params> = {}) {
+  let params: Params = {
+    paneId: "pane-1", connectionId: "conn-1", isLocal: false, isActive: true,
+    t: (key) => key, onCreateArchive: async () => ({ success: true }), onCreated: () => {},
+    ...overrides,
+  };
+  let current!: ReturnType<typeof useSftpArchiveDialog>;
+  function Probe() {
+    current = useSftpArchiveDialog(params);
+    return null;
+  }
+  let renderer!: ReactTestRenderer;
+  await act(async () => { renderer = create(React.createElement(Probe)); });
+  return {
+    get value() { return current; },
+    async update(changes: Partial<Params>) {
+      params = { ...params, ...changes };
+      await act(async () => { renderer.update(React.createElement(Probe)); });
+    },
+    async unmount() { await act(async () => { renderer.unmount(); }); },
+  };
+}
+
+test("archive dialog snapshots nested selections, format, and connection identity", async (t) => {
+  const requests: unknown[] = [];
+  const reloaded: string[] = [];
+  const harness = await mount({
+    onCreateArchive: async (options, target) => { requests.push({ options, target }); return { success: true }; },
+    onCreated: (directory) => { reloaded.push(directory); },
+  });
+  t.after(() => harness.unmount());
+  await act(async () => { harness.value.open(["/srv/site/assets", "/srv/site/assets/logo.png", "/srv/site/config/app.json"]); });
+  assert.deepEqual(harness.value.state?.paths, ["assets", "config/app.json"]);
+  assert.equal(harness.value.state?.directory, "/srv/site");
+  await act(async () => { harness.value.setArchiveName("backup.tar.gz"); harness.value.setFormat("zip"); });
+  assert.equal(harness.value.state?.archiveName, "backup.zip");
+  await act(async () => { await harness.value.submit(); });
+  assert.deepEqual(requests, [{
+    options: { directory: "/srv/site", paths: ["assets", "config/app.json"], archiveName: "backup.zip", format: "zip", overwrite: false },
+    target: { paneId: "pane-1", connectionId: "conn-1" },
+  }]);
+  assert.deepEqual(reloaded, ["/srv/site"]);
+  assert.equal(harness.value.state, null);
+});
+
+test("archive dialog requires a separate overwrite decision and revokes it on edits", async (t) => {
+  const overwriteFlags: Array<boolean | undefined> = [];
+  const harness = await mount({ onCreateArchive: async (options) => {
+    overwriteFlags.push(options.overwrite);
+    return options.overwrite ? { success: true } : { success: false, code: "EEXIST" };
+  } });
+  t.after(() => harness.unmount());
+  await act(async () => { harness.value.open(["/srv/site"]); });
+  await act(async () => { await harness.value.submit(true); });
+  assert.deepEqual(overwriteFlags, [], "overwrite is unavailable before a collision");
+  await act(async () => { await harness.value.submit(); });
+  assert.equal(harness.value.state?.confirmOverwrite, true);
+  await act(async () => { await harness.value.submit(); });
+  assert.deepEqual(overwriteFlags, [false], "Enter must not confirm overwrite");
+  await act(async () => { harness.value.setArchiveName("other.tar.gz"); });
+  assert.equal(harness.value.state?.confirmOverwrite, false);
+  await act(async () => { await harness.value.submit(true); });
+  assert.deepEqual(overwriteFlags, [false]);
+  await act(async () => { await harness.value.submit(); });
+  await act(async () => { await harness.value.submit(true); });
+  assert.deepEqual(overwriteFlags, [false, false, true]);
+  assert.equal(harness.value.state, null);
+});
+
+test("pending archive creation blocks duplicate submits, edits, and dismissal", async (t) => {
+  let finish!: (result: SftpArchiveCreationResult) => void;
+  let requests = 0;
+  const harness = await mount({ onCreateArchive: async () => {
+    requests += 1;
+    return new Promise<SftpArchiveCreationResult>((resolve) => { finish = resolve; });
+  } });
+  t.after(() => harness.unmount());
+  await act(async () => { harness.value.open(["/srv/site"]); });
+  let pending!: Promise<void>;
+  await act(async () => {
+    pending = harness.value.submit();
+    void harness.value.submit();
+    harness.value.close();
+    harness.value.setArchiveName("changed.tar.gz");
+    harness.value.open(["/different"]);
+  });
+  assert.equal(requests, 1);
+  assert.equal(harness.value.state?.busy, true);
+  assert.equal(harness.value.state?.archiveName, "site.tar.gz");
+  await act(async () => { finish({ success: true }); await pending; });
+  assert.equal(harness.value.state, null);
+});
+
+test("switching connections dismisses the old dialog and ignores its late result", async (t) => {
+  let finish!: (result: SftpArchiveCreationResult) => void;
+  const reloaded: string[] = [];
+  let requests = 0;
+  const harness = await mount({
+    onCreateArchive: async () => {
+      requests += 1;
+      return new Promise<SftpArchiveCreationResult>((resolve) => { finish = resolve; });
+    },
+    onCreated: (directory) => { reloaded.push(directory); },
+  });
+  t.after(() => harness.unmount());
+  await act(async () => { harness.value.open(["/srv/site"]); });
+  let pending!: Promise<void>;
+  await act(async () => { pending = harness.value.submit(); });
+  await harness.update({ connectionId: "conn-2" });
+  assert.equal(harness.value.state, null);
+  await act(async () => { harness.value.open(["/srv/new-site"]); });
+  await act(async () => { finish({ success: false, code: "EEXIST" }); await pending; });
+  assert.equal(requests, 1);
+  assert.equal(harness.value.state?.archiveName, "new-site.tar.gz");
+  assert.equal(harness.value.state?.confirmOverwrite, false);
+  assert.deepEqual(reloaded, []);
+});
+
+test("tab switches invalidate the old form even when its connection stays mounted", async (t) => {
+  let requests = 0;
+  const harness = await mount({ onCreateArchive: async () => { requests += 1; return { success: true }; } });
+  t.after(() => harness.unmount());
+  await act(async () => { harness.value.open(["/srv/site"]); });
+  const staleSubmit = harness.value.submit;
+  await harness.update({ isActive: false });
+  await act(async () => { await staleSubmit(); });
+  assert.equal(harness.value.state, null);
+  assert.equal(requests, 0);
+  await harness.update({ isActive: true, isLocal: true });
+  await act(async () => { harness.value.open(["/srv/site"]); });
+  assert.equal(harness.value.state, null);
+});
+
+test("invalid names do not invoke the backend; failures keep a retryable form", async (t) => {
+  let requests = 0;
+  const harness = await mount({ onCreateArchive: async () => { requests += 1; throw new Error("zip is not installed"); } });
+  t.after(() => harness.unmount());
+  await act(async () => { harness.value.open(["/srv/site"]); harness.value.setArchiveName("../backup.tar.gz"); });
+  await act(async () => { await harness.value.submit(); });
+  assert.equal(requests, 0);
+  assert.equal(harness.value.state?.error, "sftp.archive.invalidName");
+  await act(async () => { harness.value.setArchiveName("backup.tar.gz"); });
+  await act(async () => { await harness.value.submit(); });
+  assert.equal(requests, 1);
+  assert.equal(harness.value.state?.busy, false);
+  assert.equal(harness.value.state?.error, "zip is not installed");
+});

application/state/sftp/useSftpArchiveDialog.ts

@@ -0,0 +1,162 @@
+import { useCallback, useEffect, useRef, useState } from "react";
+import {
+  prepareSftpArchiveSelection,
+  validateSftpArchiveName,
+  withSftpArchiveExtension,
+  type SftpArchiveCreationOptions,
+  type SftpArchiveCreationResult,
+  type SftpArchiveCreationTarget,
+  type SftpArchiveFormat,
+} from "../../../domain/sftpArchiveCreation";
+
+export type SftpArchiveTarget = SftpArchiveCreationTarget;
+
+export interface SftpArchiveDialogState {
+  target: SftpArchiveTarget;
+  directory: string;
+  paths: string[];
+  archiveName: string;
+  format: SftpArchiveFormat;
+  busy: boolean;
+  error: string | null;
+  confirmOverwrite: boolean;
+}
+
+interface UseSftpArchiveDialogParams {
+  paneId: string;
+  connectionId?: string;
+  isLocal: boolean;
+  isActive: boolean;
+  t: (key: string, params?: Record<string, unknown>) => string;
+  onCreateArchive?: (
+    options: SftpArchiveCreationOptions,
+    target: SftpArchiveTarget,
+  ) => Promise<SftpArchiveCreationResult>;
+  onCreated: (directory: string) => void;
+}
+
+export function useSftpArchiveDialog(params: UseSftpArchiveDialogParams) {
+  const [state, setState] = useState<SftpArchiveDialogState | null>(null);
+  const stateRef = useRef(state);
+  const paramsRef = useRef(params);
+  paramsRef.current = params;
+  const generation = useRef(0);
+
+  const update = useCallback((next: SftpArchiveDialogState | null) => {
+    stateRef.current = next;
+    setState(next);
+  }, []);
+
+  const matchesTarget = useCallback((target: SftpArchiveTarget) => {
+    const current = paramsRef.current;
+    return current.isActive && !current.isLocal
+      && current.paneId === target.paneId
+      && current.connectionId === target.connectionId;
+  }, []);
+
+  // A dialog belongs to the connection and pane on which it was opened. A tab
+  // switch may leave its component mounted, so visibility is part of identity.
+  useEffect(() => {
+    if (stateRef.current && !matchesTarget(stateRef.current.target)) {
+      generation.current += 1;
+      update(null);
+    }
+  }, [params.paneId, params.connectionId, params.isLocal, params.isActive, matchesTarget, update]);
+
+  useEffect(() => () => { generation.current += 1; }, []);
+
+  const open = useCallback((sourcePaths: string[]) => {
+    const current = paramsRef.current;
+    if (!current.connectionId || current.isLocal || !current.isActive
+      || !current.onCreateArchive || stateRef.current?.busy) return;
+    generation.current += 1;
+    const target = { paneId: current.paneId, connectionId: current.connectionId };
+    try {
+      const selection = prepareSftpArchiveSelection(sourcePaths);
+      update({
+        target,
+        directory: selection.directory,
+        paths: selection.paths,
+        archiveName: withSftpArchiveExtension(selection.defaultName, "tar.gz"),
+        format: "tar.gz",
+        busy: false,
+        error: null,
+        confirmOverwrite: false,
+      });
+    } catch {
+      update({
+        target, directory: "", paths: [], archiveName: "", format: "tar.gz",
+        busy: false, error: current.t("sftp.archive.invalidSelection"), confirmOverwrite: false,
+      });
+    }
+  }, [update]);
+
+  const close = useCallback(() => {
+    if (stateRef.current?.busy) return;
+    generation.current += 1;
+    update(null);
+  }, [update]);
+
+  const setArchiveName = useCallback((archiveName: string) => {
+    const current = stateRef.current;
+    if (!current || current.busy) return;
+    update({ ...current, archiveName, error: null, confirmOverwrite: false });
+  }, [update]);
+
+  const setFormat = useCallback((format: SftpArchiveFormat) => {
+    const current = stateRef.current;
+    if (!current || current.busy) return;
+    update({
+      ...current, format,
+      archiveName: withSftpArchiveExtension(current.archiveName, format),
+      error: null, confirmOverwrite: false,
+    });
+  }, [update]);
+
+  const submit = useCallback(async (overwrite = false) => {
+    const current = stateRef.current;
+    const { onCreateArchive, t } = paramsRef.current;
+    if (!current || current.busy || !onCreateArchive || !matchesTarget(current.target)
+      || current.paths.length === 0 || (overwrite && !current.confirmOverwrite)) return;
+    // Enter in the name field must not implicitly confirm replacement.
+    if (current.confirmOverwrite && !overwrite) return;
+    const validationError = validateSftpArchiveName(current.archiveName, current.format);
+    if (validationError) {
+      update({ ...current, error: t(validationError) });
+      return;
+    }
+    const requestGeneration = generation.current;
+    update({ ...current, busy: true, error: null });
+    try {
+      const result = await onCreateArchive({
+        directory: current.directory,
+        paths: current.paths,
+        archiveName: current.archiveName,
+        format: current.format,
+        overwrite,
+      }, current.target);
+      if (generation.current !== requestGeneration || !matchesTarget(current.target)) return;
+      if (!result.success) {
+        update({
+          ...current, busy: false,
+          confirmOverwrite: result.code === "EEXIST",
+          error: result.code === "EEXIST" ? null : result.error || t("sftp.archive.failed"),
+        });
+        return;
+      }
+      update(null);
+      paramsRef.current.onCreated(current.directory);
+    } catch (error) {
+      if (generation.current !== requestGeneration || !matchesTarget(current.target)) return;
+      update({
+        ...current, busy: false, confirmOverwrite: false,
+        error: error instanceof Error ? error.message : String(error),
+      });
+    }
+  }, [matchesTarget, update]);
+
+  return {
+    state: state && matchesTarget(state.target) ? state : null,
+    open, close, setArchiveName, setFormat, submit,
+  };
+}

application/state/sftp/useSftpTransfers.ts

@@ -1326,6 +1326,13 @@ export const useSftpTransfers = ({
         sourcePath?: string;
         sourceConnectionId?: string;
         targetPath?: string;
+        /**
+         * Create copies next to the originals instead of prompting for the
+         * same-name conflict. Each source name is resolved to the next free
+         * `name (copy)`, `name (copy 2)`, ... before the transfer starts.
+         * Used by the SFTP context menu's Duplicate action.
+         */
+        duplicate?: boolean;
         onTransferComplete?: (result: TransferResult) => void | Promise<void>;
       },
     ) => {
@@ -1429,6 +1436,10 @@ export const useSftpTransfers = ({
       }
 
       for (const file of sourceFiles) {
+        // "." / ".." are navigation rows, not real entries. Duplicating one
+        // would resolve to an ancestor (e.g. "/") and could walk the copy into
+        // its own output.
+        if (options?.duplicate && (file.name === "." || file.name === "..")) continue;
         const direction: TransferDirection =
           sourcePane.connection!.isLocal && !targetPane.connection!.isLocal
             ? "upload"
@@ -1461,8 +1472,36 @@ export const useSftpTransfers = ({
           : (freshMetadata?.lastModified ?? fileEntry?.lastModified ?? 0);
 
         const nextSourcePath = joinPath(sourcePath, file.name);
-        const nextTargetPath = joinPath(targetPath, file.name);
         const targetIsLocal = targetPane.connection!.isLocal;
+        // A duplicate targets the folder the item already lives in, so the
+        // same-name conflict is guaranteed. Resolve the "(copy)" name up front
+        // instead of routing through the conflict dialog: the one-click action
+        // must not prompt, and resolving it inside processTransfer would
+        // re-enter the same task while it is still marked in flight.
+        const duplicateTarget = options?.duplicate
+          ? await getDuplicateTarget(
+              { fileName: file.name, isDirectory: file.isDirectory, targetPath: joinPath(targetPath, file.name) },
+              targetPane,
+              targetIsLocal ? null : (sftpSessionsRef.current.get(targetPane.connection!.id) ?? null),
+              targetIsLocal ? "auto" : (targetPane.filenameEncoding || "auto"),
+              // A queued or paused copy has not created its destination on disk
+              // yet, so the next duplicate would pick the same name and surface
+              // a conflict dialog. Reserve active destinations while naming.
+              (candidatePath) => Boolean(findActivePathConflict(
+                [...sftpTransferCenterStore.getSnapshot().tasks, ...transfersRef.current, ...newTasks],
+                {
+                  id: "",
+                  targetPath: candidatePath,
+                  targetConnectionId: targetIsLocal ? "local" : targetPane.connection!.id,
+                  targetHostId: targetIsLocal ? undefined : targetPane.connection!.hostId,
+                  targetHostLabel: targetIsLocal ? "Local" : targetPane.connection!.hostLabel,
+                  isDirectory: file.isDirectory,
+                },
+              )),
+            )
+          : null;
+        const nextFileName = duplicateTarget?.fileName ?? file.name;
+        const nextTargetPath = duplicateTarget?.targetPath ?? joinPath(targetPath, file.name);
         const pathTaken = findActivePathConflict(
           [...sftpTransferCenterStore.getSnapshot().tasks, ...transfersRef.current, ...newTasks],
           {
@@ -1481,7 +1520,7 @@ export const useSftpTransfers = ({
           const attentionTask: TransferTask = {
             id: crypto.randomUUID(),
             batchId,
-            fileName: file.name,
+            fileName: nextFileName,
             originalFileName: file.name,
             sourcePath: nextSourcePath,
             targetPath: nextTargetPath,
@@ -1522,7 +1561,7 @@ export const useSftpTransfers = ({
         newTasks.push({
           id: taskId,
           batchId,
-          fileName: file.name,
+          fileName: nextFileName,
           originalFileName: file.name,
           sourcePath: nextSourcePath,
           targetPath: nextTargetPath,

application/state/sftp/useSftpTransfers.types.ts

@@ -36,6 +36,12 @@ export interface UseSftpTransfersResult {
       sourcePath?: string;
       sourceConnectionId?: string;
       targetPath?: string;
+      /**
+       * Create copies next to the originals instead of prompting for the
+       * same-name conflict. Each source name is resolved to the next free
+       * `name (copy)`, `name (copy 2)`, ... before the transfer starts.
+       */
+      duplicate?: boolean;
       onTransferComplete?: (result: TransferResult) => void | Promise<void>;
     },
   ) => Promise<TransferResult[]>;

application/state/terminalCwdStore.test.ts

@@ -30,3 +30,20 @@ test('terminalCwdStore bumps version only when cwd or provenance changes', () =>
   unsubscribe();
   assert.ok(versions.length >= 2);
 });
+
+test('session revisions isolate terminals and retain identical OSC 7 reports without rerendering', () => {
+  const a = 'revision-a'; const b = 'revision-b';
+  terminalCwdStore.setCwd(a, '/same', 'osc7');
+  const revisionA = terminalCwdStore.getSessionRevision(a);
+  terminalCwdStore.setCwd(b, '/elsewhere', 'osc7');
+  assert.equal(terminalCwdStore.getSessionRevision(a), revisionA);
+  const globalVersion = terminalCwdStore.getVersion();
+  assert.equal(terminalCwdStore.setCwd(a, '/same', 'osc7'), false);
+  assert.ok(terminalCwdStore.getSessionRevision(a) > revisionA);
+  assert.equal(terminalCwdStore.getVersion(), globalVersion);
+  const revisionB = terminalCwdStore.getSessionRevision(b);
+  terminalCwdStore.prune(new Set([b]));
+  assert.equal(terminalCwdStore.getSessionRevision(a), 0);
+  assert.equal(terminalCwdStore.getSessionRevision(b), revisionB);
+  terminalCwdStore.prune(new Set());
+});

application/state/terminalCwdStore.ts

@@ -10,11 +10,16 @@ export type TerminalCwdSource = "osc7" | "inferred" | "backend-strict" | "backen
 class TerminalCwdStore {
   private cwdBySession = new Map<string, string>();
   private sourceBySession = new Map<string, TerminalCwdSource>();
+  private revisionBySession = new Map<string, number>();
+  private revision = 0;
   private version = 0;
   private listeners = new Set<Listener>();
 
   getVersion = (): number => this.version;
 
+  /** Tracks reports for one session, including unchanged authoritative OSC 7. */
+  getSessionRevision = (sessionId: string): number => this.revisionBySession.get(sessionId) ?? 0;
+
   getCwd = (sessionId: string | null | undefined): string | null => {
     if (!sessionId) return null;
     return this.cwdBySession.get(sessionId) ?? null;
@@ -39,7 +44,10 @@ class TerminalCwdStore {
     const nextSource = next
       ? (source ?? (current === next ? currentSource : undefined) ?? "unknown")
       : undefined;
-    if (current === next && currentSource === nextSource) return false;
+    if (current === next && currentSource === nextSource) {
+      if (nextSource === 'osc7') this.revisionBySession.set(sessionId, ++this.revision);
+      return false;
+    }
 
     if (next) {
       this.cwdBySession.set(sessionId, next);
@@ -48,6 +56,7 @@ class TerminalCwdStore {
       this.cwdBySession.delete(sessionId);
       this.sourceBySession.delete(sessionId);
     }
+    this.revisionBySession.set(sessionId, ++this.revision);
     this.version += 1;
     for (const listener of this.listeners) {
       listener();
@@ -61,9 +70,13 @@ class TerminalCwdStore {
       if (!validSessionIds.has(sessionId)) {
         this.cwdBySession.delete(sessionId);
         this.sourceBySession.delete(sessionId);
+        this.revisionBySession.delete(sessionId);
         changed = true;
       }
     }
+    for (const id of this.revisionBySession.keys()) {
+      if (!validSessionIds.has(id)) this.revisionBySession.delete(id);
+    }
     if (!changed) return;
     this.version += 1;
     for (const listener of this.listeners) {

application/state/terminalDirectoryController.test.ts

@@ -0,0 +1,230 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { createTerminalDirectoryController } from './terminalDirectoryController';
+import { terminalCwdStore } from './terminalCwdStore';
+import type { TerminalDirectoryIO } from '../../infrastructure/services/terminalDirectory';
+
+function setup(overrides: Partial<TerminalDirectoryIO> = {}) {
+  let cwd = '/old'; let ready = true; let current = true;
+  const writes: string[] = [];
+  const published: string[] = [];
+  const controller = createTerminalDirectoryController({
+    sessionId: 'test-directory', confirmationMs: 10,
+    io: { cwd: async () => cwd, list: async () => ({ entries: [], home: null }), realpath: async path => path,
+      write: data => { writes.push(data); cwd = '/next'; }, ...overrides },
+    isCurrent: () => current, isReady: () => ready,
+    publish: value => { published.push(value); terminalCwdStore.setCwd('test-directory', value, 'backend-strict'); },
+  });
+  return { controller, writes, published, busy: () => { ready = false; }, stale: () => { current = false; } };
+}
+
+test('navigation writes one quoted cd and waits for actual cwd before confirming', async () => {
+  const ctx = setup(); const accepted: string[] = [];
+  await ctx.controller.change('/next', new AbortController().signal, () => accepted.push('accepted'));
+  assert.deepEqual(ctx.writes, ["cd -- '/next'\r"]);
+  assert.deepEqual(accepted, ['accepted']);
+  assert.deepEqual(ctx.published, ['/next']);
+  ctx.controller.dispose();
+});
+
+test('busy, control-character and stale sessions never receive bytes', async () => {
+  const ctx = setup(); ctx.busy();
+  await assert.rejects(ctx.controller.change('/next', new AbortController().signal, () => {}), { code: 'busy' });
+  const invalid = setup();
+  await assert.rejects(invalid.controller.change('/next\n', new AbortController().signal, () => {}), { code: 'unsupportedPath' });
+  const stale = setup(); stale.stale();
+  await assert.rejects(stale.controller.change('/next', new AbortController().signal, () => {}), { code: 'unavailable' });
+  assert.deepEqual([...ctx.writes, ...invalid.writes, ...stale.writes], []);
+});
+
+test('rechecks readiness after async path resolution; double submission is rejected', async () => {
+  let finish!: (path: string) => void;
+  const ctx = setup({ realpath: () => new Promise(resolve => { finish = resolve; }) });
+  const first = ctx.controller.change('/next', new AbortController().signal, () => {});
+  await assert.rejects(ctx.controller.change('/other', new AbortController().signal, () => {}), { code: 'busy' });
+  ctx.busy(); finish('/next');
+  await assert.rejects(first, { code: 'busy' });
+  assert.deepEqual(ctx.writes, []);
+});
+
+test('a disposed connection rejects delayed reads and cannot publish into a new generation', async () => {
+  let finish!: (cwd: string) => void;
+  const ctx = setup({ cwd: () => new Promise(resolve => { finish = resolve; }) });
+  const read = ctx.controller.refresh();
+  ctx.controller.dispose(); finish('/stale');
+  await assert.rejects(read, { code: 'unavailable' });
+  assert.deepEqual(ctx.published, []);
+});
+
+test('a failed cd keeps the observed cwd and never retries the write', async () => {
+  const ctx = setup({ write: () => {}, cwd: async () => '/old' });
+  await assert.rejects(ctx.controller.change('/missing', new AbortController().signal, () => {}), { code: 'changeFailed' });
+  assert.ok(ctx.published.every(value => value === '/old'));
+});
+
+test('directory symlinks confirm against physical cwd', async () => {
+  const ctx = setup({ realpath: async path => path === '/link' ? '/real' : path, cwd: async () => '/real' });
+  await ctx.controller.change('/link', new AbortController().signal, () => {});
+  assert.equal(ctx.published.at(-1), '/real');
+});
+
+test('output arriving during an old cwd query retains one fresh follow-up query', async () => {
+  let finish!: (cwd: string) => void;
+  let reads = 0;
+  const ctx = setup({ cwd: () => {
+    reads++;
+    return reads === 1 ? new Promise(resolve => { finish = resolve; }) : Promise.resolve('/after-cd');
+  } });
+  const oldRead = ctx.controller.refresh();
+  const queued = ctx.controller.refresh();
+  finish('/before-cd');
+  await Promise.all([oldRead, queued]);
+  await new Promise(resolve => setImmediate(resolve));
+  assert.equal(reads, 2);
+  assert.equal(ctx.published.at(-1), '/after-cd');
+  ctx.controller.dispose();
+});
+
+test('another terminal updating cannot override the current terminal strict cwd result', async t => {
+  const id = 'strict-after-other-session';
+  let finish!: (cwd: string) => void;
+  const published: string[] = [];
+  terminalCwdStore.setCwd(id, '/stale-osc7', 'stale');
+  const controller = createTerminalDirectoryController({
+    sessionId: id, isCurrent: () => true, isReady: () => true,
+    io: { cwd: () => new Promise(resolve => { finish = resolve; }),
+      list: async () => ({ entries: [], home: null }), realpath: async value => value, write() {} },
+    publish: value => { published.push(value); terminalCwdStore.setCwd(id, value, 'backend-strict'); },
+  });
+  t.after(() => controller.dispose());
+  const pending = controller.refresh();
+  terminalCwdStore.setCwd('unrelated-session', '/other', 'osc7');
+  finish('/actual-after-cd');
+  assert.equal(await pending, '/actual-after-cd');
+  assert.deepEqual(published, ['/actual-after-cd']);
+  assert.equal(terminalCwdStore.getCwd(id), '/actual-after-cd');
+});
+
+test('another terminal cannot turn this submission pre-write OSC 7 into a fresh report', async t => {
+  const id = 'pre-write-osc7-after-other-session';
+  let finish!: (cwd: string) => void;
+  const published: string[] = [];
+  terminalCwdStore.setCwd(id, '/before', 'osc7');
+  const controller = createTerminalDirectoryController({
+    sessionId: id, confirmationMs: 20, isCurrent: () => true, isReady: () => true,
+    io: { cwd: () => new Promise(resolve => { finish = resolve; }),
+      list: async () => ({ entries: [], home: null }), realpath: async value => value, write() {} },
+    publish: cwd => { published.push(cwd); terminalCwdStore.setCwd(id, cwd, 'backend-strict'); },
+  });
+  t.after(() => controller.dispose());
+  const changing = controller.change('/after', new AbortController().signal, () => {});
+  await new Promise(resolve => setImmediate(resolve));
+  terminalCwdStore.setCwd(id + '-other', '/other', 'osc7');
+  finish('/after');
+  await changing;
+  assert.deepEqual(published, ['/after']);
+  assert.equal(terminalCwdStore.getCwd(id), '/after');
+});
+
+for (const nextCwd of ['/new-osc7', '/original']) {
+  test(`a later OSC 7 report from this terminal wins (${nextCwd})`, async t => {
+    const id = 'same-session-osc7-' + nextCwd;
+    let finish!: (cwd: string) => void;
+    const published: string[] = [];
+    terminalCwdStore.setCwd(id, '/original', 'stale');
+    const controller = createTerminalDirectoryController({
+      sessionId: id, isCurrent: () => true, isReady: () => true,
+      io: { cwd: () => new Promise(resolve => { finish = resolve; }),
+        list: async () => ({ entries: [], home: null }), realpath: async value => value, write() {} },
+      publish: value => { published.push(value); },
+    });
+    t.after(() => controller.dispose());
+    const pending = controller.refresh();
+    terminalCwdStore.setCwd(id, nextCwd, 'osc7');
+    finish('/older-backend-result');
+    assert.equal(await pending, nextCwd);
+    assert.deepEqual(published, []);
+  });
+}
+
+for (const probe of ['fails', 'stalls'] as const) {
+  test(`a fresh post-write OSC 7 confirms navigation when the strict cwd probe ${probe}`, { timeout: 2000 }, async t => {
+    const id = 'osc7-confirm-' + probe;
+    const writes: string[] = [];
+    terminalCwdStore.setCwd(id, '/old', 'osc7');
+    const controller = createTerminalDirectoryController({
+      sessionId: id, confirmationMs: 1000, isCurrent: () => true, isReady: () => true,
+      io: {
+        cwd: () => probe === 'fails' ? Promise.reject(new Error('no process cwd support')) : new Promise(() => {}),
+        list: async () => ({ entries: [], home: null }), realpath: async value => value,
+        write: data => {
+          writes.push(data);
+          setImmediate(() => terminalCwdStore.setCwd(id, '/next', 'osc7'));
+        },
+      },
+      publish() { assert.fail('an unavailable probe must not publish a guessed cwd'); },
+    });
+    t.after(() => controller.dispose());
+    await controller.change('/next', new AbortController().signal, () => {});
+    assert.deepEqual(writes, ["cd -- '/next'\r"]);
+    assert.equal(controller.hasConfirmedCwd(), true);
+  });
+}
+
+test('navigation can probe past its pre-write OSC 7 when the shell stops reporting', async t => {
+  const id = 'probe-after-pre-write-osc7';
+  terminalCwdStore.setCwd(id, '/before', 'osc7');
+  const controller = createTerminalDirectoryController({
+    sessionId: id, isCurrent: () => true, isReady: () => true,
+    io: { cwd: async () => '/after', list: async () => ({ entries: [], home: null }),
+      realpath: async value => value, write() {} },
+    publish: cwd => terminalCwdStore.setCwd(id, cwd, 'backend-strict'),
+  });
+  t.after(() => controller.dispose());
+  await controller.change('/after', new AbortController().signal, () => {});
+  assert.equal(terminalCwdStore.getCwd(id), '/after');
+  assert.equal(terminalCwdStore.getSource(id), 'backend-strict');
+});
+
+for (const report of ['stale', 'other-session', 'other-source', 'fresh-unchanged'] as const) {
+  test(`OSC 7 confirmation uses this submission's session revision (${report})`, { timeout: 2000 }, async t => {
+    const id = 'osc7-revision-confirm-' + report;
+    terminalCwdStore.setCwd(id, '/next', 'osc7');
+    const controller = createTerminalDirectoryController({
+      sessionId: id, confirmationMs: 20, isCurrent: () => true, isReady: () => true,
+      io: {
+        cwd: async () => { throw new Error('no process cwd support'); },
+        list: async () => ({ entries: [], home: null }), realpath: async value => value,
+        write() {
+          if (report !== 'stale') setImmediate(() => terminalCwdStore.setCwd(
+            report === 'other-session' ? id + '-other' : id, '/next', report === 'other-source' ? 'inferred' : 'osc7',
+          ));
+        },
+      },
+      publish() {},
+    });
+    t.after(() => controller.dispose());
+    const change = controller.change('/next', new AbortController().signal, () => {});
+    if (report === 'fresh-unchanged') await change;
+    else await assert.rejects(change, { code: 'changeFailed' });
+  });
+}
+
+for (const cancellation of ['abort', 'dispose'] as const) {
+  test(`a fresh OSC 7 cannot confirm a cancelled directory change (${cancellation})`, { timeout: 2000 }, async t => {
+    const id = 'osc7-cancel-' + cancellation;
+    const abort = new AbortController();
+    const controller = createTerminalDirectoryController({
+      sessionId: id, isCurrent: () => true, isReady: () => true,
+      io: { cwd: () => new Promise(() => {}), list: async () => ({ entries: [], home: null }),
+        realpath: async value => value,
+        write() { setImmediate(() => {
+          if (cancellation === 'abort') abort.abort(); else controller.dispose();
+          terminalCwdStore.setCwd(id, '/next', 'osc7');
+        }); } },
+      publish() {},
+    });
+    t.after(() => controller.dispose());
+    await assert.rejects(controller.change('/next', abort.signal, () => {}), { code: 'unavailable' });
+  });
+}

application/state/terminalDirectoryController.ts

@@ -0,0 +1,162 @@
+import { DirectoryPickerError, isDirectoryPath } from '../../domain/directoryPicker';
+import { resolveInteractiveTerminalCdIntent } from '../../domain/sessionRestore';
+import type { TerminalDirectoryIO } from '../../infrastructure/services/terminalDirectory';
+import { terminalCwdStore } from './terminalCwdStore';
+
+export type TerminalDirectoryController = ReturnType<typeof createTerminalDirectoryController>;
+
+/** One registration represents one connected interactive shell generation. */
+export function createTerminalDirectoryController(options: {
+  sessionId: string;
+  io: TerminalDirectoryIO;
+  isCurrent: () => boolean;
+  isReady: () => boolean;
+  publish: (cwd: string) => void;
+  confirmationMs?: number;
+}) {
+  let disposed = false;
+  let changing = false;
+  let confirmed = false;
+  let refreshing: Promise<string> | null = null;
+  let refreshAgain = false;
+  const lifetime = new AbortController();
+  const current = () => !disposed && options.isCurrent();
+  function check(signal?: AbortSignal) {
+    if (!current() || signal?.aborted) throw new DirectoryPickerError('unavailable');
+  }
+  function ready() {
+    check();
+    if (!options.isReady()) throw new DirectoryPickerError('busy');
+  }
+  function bounded<T>(task: Promise<T>, signal?: AbortSignal): Promise<T> {
+    return new Promise((resolve, reject) => {
+      const finish = (error?: unknown, value?: T) => {
+        clearTimeout(timer);
+        lifetime.signal.removeEventListener('abort', cancel);
+        signal?.removeEventListener('abort', cancel);
+        if (error) reject(error); else resolve(value!);
+      };
+      const cancel = () => finish(new DirectoryPickerError('unavailable'));
+      const timer = setTimeout(() => finish(new DirectoryPickerError('readFailed')), 5000);
+      lifetime.signal.addEventListener('abort', cancel, { once: true });
+      signal?.addEventListener('abort', cancel, { once: true });
+      if (signal?.aborted || lifetime.signal.aborted) cancel();
+      task.then(value => finish(undefined, value), error => finish(error));
+    });
+  }
+  async function refresh(submittedRevision?: number): Promise<string> {
+    check();
+    const activeShellCwd = () => {
+      const cwd = terminalCwdStore.getCwd(options.sessionId);
+      return cwd && terminalCwdStore.getSource(options.sessionId) === 'osc7'
+        && (submittedRevision === undefined || terminalCwdStore.getSessionRevision(options.sessionId) !== submittedRevision)
+        ? cwd : null;
+    };
+    // A process probe may read the outer PTY shell while a nested shell is
+    // active. OSC 7 remains authoritative across debounce delays, completion
+    // events and picker remounts. Only a cd submission may probe past its own
+    // pre-write report while waiting for fresh confirmation.
+    const reported = activeShellCwd();
+    if (reported) { confirmed = true; return reported; }
+    if (refreshing) {
+      // Output may settle while a pre-cd query is still in flight. Keep one
+      // follow-up query so that its older result cannot be the last update.
+      refreshAgain = true;
+      return refreshing;
+    }
+    const pending = (async () => {
+      const cwd = await bounded(options.io.cwd());
+      check();
+      const reported = activeShellCwd();
+      const live = terminalCwdStore.getCwd(options.sessionId);
+      confirmed = true;
+      if (reported) return reported;
+      if (live !== cwd || terminalCwdStore.getSource(options.sessionId) === 'stale') options.publish(cwd);
+      return cwd;
+    })();
+    refreshing = pending;
+    try { return await pending; } finally {
+      if (refreshing === pending) refreshing = null;
+      if (refreshAgain && current()) {
+        refreshAgain = false;
+        void refresh().catch(() => {});
+      }
+    }
+  }
+  async function change(path: string, signal: AbortSignal, accepted: () => void, expectedCwd?: string) {
+    ready();
+    if (changing) throw new DirectoryPickerError('busy');
+    const intent = isDirectoryPath(path) ? resolveInteractiveTerminalCdIntent(path) : null;
+    if (!intent) throw new DirectoryPickerError('unsupportedPath');
+    changing = true;
+    let confirmationFinished = false;
+    try {
+      const canonical = await bounded(options.io.realpath(path, signal), signal);
+      check(signal);
+      ready(); // The shell can become busy while resolving a remote symlink.
+      if (expectedCwd && terminalCwdStore.getCwd(options.sessionId) !== expectedCwd) throw new DirectoryPickerError('unavailable');
+      const submittedRevision = terminalCwdStore.getSessionRevision(options.sessionId);
+      options.io.write(intent.command + '\r');
+      accepted();
+      const deadline = Date.now() + (options.confirmationMs ?? 8000);
+      const hasFreshOsc7 = () => {
+        const cwd = terminalCwdStore.getCwd(options.sessionId);
+        return terminalCwdStore.getSessionRevision(options.sessionId) !== submittedRevision
+          && terminalCwdStore.getSource(options.sessionId) === 'osc7'
+          && (cwd === path || cwd === canonical);
+      };
+      const pause = () => new Promise<void>(resolve => {
+        const done = () => { clearTimeout(timer); lifetime.signal.removeEventListener('abort', done); resolve(); };
+        const timer = setTimeout(done, 200);
+        lifetime.signal.addEventListener('abort', done, { once: true });
+      });
+      const confirmFromProbe = async () => {
+        while (!confirmationFinished && Date.now() < deadline) {
+          check(signal);
+          if (hasFreshOsc7()) return;
+          if (options.isReady()) {
+            try {
+              const cwd = await refresh(submittedRevision);
+              check(signal);
+              if (cwd === path || cwd === canonical || await bounded(options.io.realpath(cwd, signal), signal) === canonical) return;
+            } catch (error) {
+              if (!current() || signal.aborted) throw error;
+            }
+          }
+          await pause();
+        }
+        if (!confirmationFinished) throw new DirectoryPickerError('changeFailed');
+      };
+      // OSC 7 is authoritative even when process cwd lookup is unavailable or
+      // stalled. Poll revisions too: an unchanged OSC 7 path emits no store event.
+      const confirmFromOsc7 = async () => {
+        while (!confirmationFinished) {
+          check(signal);
+          if (hasFreshOsc7()) return;
+          if (Date.now() >= deadline) throw new DirectoryPickerError('changeFailed');
+          await pause();
+        }
+      };
+      await Promise.race([confirmFromProbe(), confirmFromOsc7()]);
+      check(signal);
+      confirmed = true;
+    } finally { confirmationFinished = true; changing = false; }
+  }
+  return {
+    refresh: () => refresh(),
+    hasConfirmedCwd: () => confirmed,
+    async home() {
+      check();
+      const result = await bounded(options.io.home?.() ?? Promise.resolve(null));
+      check(); return result;
+    },
+    async list(path: string, signal: AbortSignal) {
+      check(signal);
+      const result = await bounded(options.io.list(path, signal), signal);
+      check(signal);
+      return result;
+    },
+    change,
+    dispose() { disposed = true; lifetime.abort(); },
+  };
+}

application/state/terminalDirectoryRegistry.test.ts

@@ -0,0 +1,87 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { createTerminalDirectoryController } from './terminalDirectoryController';
+import { terminalCwdStore } from './terminalCwdStore';
+import {
+  observeTerminalDirectory, registerTerminalDirectory,
+  refreshObservedTerminalDirectory, scheduleObservedTerminalDirectoryRefresh,
+} from './terminalDirectoryRegistry';
+
+test('manual terminal output refreshes cwd without a trusted command-completion event', async t => {
+  t.mock.timers.enable({ apis: ['setTimeout'] });
+  let cwd = '/before'; let reads = 0;
+  const published: string[] = [];
+  const controller = createTerminalDirectoryController({
+    sessionId: 'unrecognized-prompt', isCurrent: () => true, isReady: () => false,
+    io: { cwd: async () => { reads++; return cwd; },
+      list: async () => ({ entries: [], home: null }), realpath: async value => value, write() {} },
+    publish: value => { published.push(value); },
+  });
+  const unregister = registerTerminalDirectory('unrecognized-prompt', controller);
+  const stopObserving = observeTerminalDirectory('unrecognized-prompt');
+  t.after(() => { stopObserving(); unregister(); });
+  cwd = '/after-manual-cd';
+  // Multiple prompt/output chunks produce just one read. No trusted prompt
+  // detection, command-completed callback, or parsed `cd` is involved.
+  scheduleObservedTerminalDirectoryRefresh('unrecognized-prompt');
+  t.mock.timers.tick(80);
+  scheduleObservedTerminalDirectoryRefresh('unrecognized-prompt');
+  t.mock.timers.tick(149);
+  assert.equal(reads, 0);
+  t.mock.timers.tick(1);
+  await new Promise(resolve => setImmediate(resolve));
+  assert.deepEqual(published, ['/after-manual-cd']);
+  assert.equal(reads, 1);
+  t.mock.timers.tick(60_000);
+  assert.equal(reads, 1, 'no polling after output has settled');
+});
+
+test('settled output and prompt completion preserve the active nested shell OSC 7 cwd', async t => {
+  t.mock.timers.enable({ apis: ['setTimeout'] });
+  const id = 'nested-shell-output';
+  const published: string[] = [];
+  const controller = createTerminalDirectoryController({
+    sessionId: id, isCurrent: () => true, isReady: () => true,
+    // The PTY process stays in its original directory while a child shell
+    // runs in /. Its cwd is only a fallback for shells without OSC 7.
+    io: { cwd: async () => '/outer-shell', list: async () => ({ entries: [], home: null }),
+      realpath: async value => value, write() {} },
+    publish: cwd => { published.push(cwd); terminalCwdStore.setCwd(id, cwd, 'backend-strict'); },
+  });
+  const unregister = registerTerminalDirectory(id, controller);
+  const stopObserving = observeTerminalDirectory(id);
+  t.after(() => { stopObserving(); unregister(); });
+  scheduleObservedTerminalDirectoryRefresh(id);
+  terminalCwdStore.setCwd(id, '/', 'osc7');
+  t.mock.timers.tick(150);
+  await new Promise(resolve => setImmediate(resolve));
+  assert.equal(terminalCwdStore.getCwd(id), '/');
+  // Later output chunks, prompt completion and reopening/manual refresh must
+  // not treat that same active-shell report as stale merely due to timing.
+  scheduleObservedTerminalDirectoryRefresh(id);
+  t.mock.timers.tick(150);
+  refreshObservedTerminalDirectory(id);
+  assert.equal(await controller.refresh(), '/');
+  assert.deepEqual(published, []);
+  assert.equal(terminalCwdStore.getSource(id), 'osc7');
+});
+
+test('disabling chips cancels a queued output refresh and ignores future terminal output', async t => {
+  t.mock.timers.enable({ apis: ['setTimeout'] });
+  let reads = 0;
+  const controller = createTerminalDirectoryController({
+    sessionId: 'hidden-chips', isCurrent: () => true, isReady: () => true,
+    io: { cwd: async () => { reads++; return '/unused'; }, list: async () => ({ entries: [], home: null }),
+      realpath: async value => value, write() {} }, publish() {},
+  });
+  const unregister = registerTerminalDirectory('hidden-chips', controller);
+  t.after(unregister);
+  const stopObserving = observeTerminalDirectory('hidden-chips');
+  scheduleObservedTerminalDirectoryRefresh('hidden-chips');
+  stopObserving();
+  t.mock.timers.tick(1000);
+  scheduleObservedTerminalDirectoryRefresh('hidden-chips');
+  t.mock.timers.tick(1000);
+  await new Promise(resolve => setImmediate(resolve));
+  assert.equal(reads, 0);
+});

application/state/terminalDirectoryRegistry.ts

@@ -0,0 +1,58 @@
+import type { TerminalDirectoryController } from './terminalDirectoryController';
+
+const sessions = new Map<string, TerminalDirectoryController>();
+const consumers = new Map<string, number>();
+const scheduledRefreshes = new Map<string, ReturnType<typeof setTimeout>>();
+const OUTPUT_SETTLE_MS = 150;
+
+function cancelScheduledRefresh(id: string) {
+  const timer = scheduledRefreshes.get(id);
+  if (timer !== undefined) clearTimeout(timer);
+  scheduledRefreshes.delete(id);
+}
+const listeners = new Set<() => void>();
+export const subscribeTerminalDirectories = (listener: () => void) => {
+  listeners.add(listener);
+  return () => { listeners.delete(listener); };
+};
+export const getTerminalDirectory = (id: string) => sessions.get(id) ?? null;
+export function registerTerminalDirectory(id: string, controller: TerminalDirectoryController) {
+  cancelScheduledRefresh(id);
+  sessions.set(id, controller);
+  listeners.forEach(listener => listener());
+  return () => {
+    controller.dispose();
+    if (sessions.get(id) !== controller) return;
+    cancelScheduledRefresh(id);
+    sessions.delete(id);
+    listeners.forEach(listener => listener());
+  };
+}
+export function observeTerminalDirectory(id: string) {
+  consumers.set(id, (consumers.get(id) ?? 0) + 1);
+  return () => {
+    const next = (consumers.get(id) ?? 1) - 1;
+    if (next) consumers.set(id, next);
+    else { consumers.delete(id); cancelScheduledRefresh(id); }
+  };
+}
+/** Called by the existing command completion path, only while chips are visible. */
+export function refreshObservedTerminalDirectory(id: string) {
+  cancelScheduledRefresh(id);
+  if (consumers.has(id)) void sessions.get(id)?.refresh().catch(() => {});
+}
+
+/**
+ * Shells with custom prompts may emit neither OSC 7/133 nor a trusted command
+ * completion. Debounce actual output/submission activity instead of polling or
+ * interpreting `cd` text. The controller prefers active-shell OSC 7 and uses
+ * the bound shell's process cwd only as a fallback.
+ */
+export function scheduleObservedTerminalDirectoryRefresh(id: string) {
+  if (!consumers.has(id) || !sessions.has(id)) return;
+  cancelScheduledRefresh(id);
+  scheduledRefreshes.set(id, setTimeout(() => {
+    scheduledRefreshes.delete(id);
+    refreshObservedTerminalDirectory(id);
+  }, OUTPUT_SETTLE_MS));
+}

application/state/testSupport/fakeIndexedDb.ts

@@ -0,0 +1,215 @@
+/**
+ * Minimal in-memory IndexedDB stub covering the exact subset used by
+ * `aiSessionIdbStorage.ts`: open + upgrade (createObjectStore), readonly
+ * getAll/get, readwrite put/delete/clear, and meta-store records. Not a
+ * general-purpose IDB implementation — extend deliberately if the wrapper
+ * grows new usage.
+ */
+
+type Resolve = () => void;
+
+const microtask2 = (fn: Resolve) => {
+  queueMicrotask(() => queueMicrotask(fn));
+};
+
+export class FakeRequest<T> {
+  onsuccess: ((this: FakeRequest<T>, ev?: unknown) => void) | null = null;
+  onerror: ((this: FakeRequest<T>, ev?: unknown) => void) | null = null;
+  onupgradeneeded: ((this: FakeRequest<T>, ev?: unknown) => void) | null = null;
+  result: T;
+  error: Error | null = null;
+
+  constructor(result: T, mode: 'immediate' | 'upgrade' | 'failure' = 'immediate', error?: Error) {
+    this.result = result;
+    if (mode === 'failure') {
+      this.error = error ?? new Error('fake idb failure');
+      queueMicrotask(() => this.onerror?.(this));
+      return;
+    }
+    queueMicrotask(() => {
+      if (mode === 'upgrade') this.onupgradeneeded?.(this);
+      this.onsuccess?.(this);
+    });
+  }
+}
+
+interface StoreSpec {
+  name: string;
+  keyPath: string;
+}
+
+export class FakeObjectStore {
+  /** Instrumentation for per-record write assertions. */
+  putCount = 0;
+  deleteCount = 0;
+
+  constructor(
+    public readonly spec: StoreSpec,
+    public readonly records: Map<string, unknown>,
+  ) {}
+
+  put(value: unknown): FakeRequest<IDBValidKey> {
+    this.putCount += 1;
+    const key = (value as Record<string, unknown>)[this.spec.keyPath] as string;
+    this.records.set(key, value);
+    return new FakeRequest(key);
+  }
+
+  delete(key: IDBValidKey): FakeRequest<undefined> {
+    this.deleteCount += 1;
+    this.records.delete(String(key));
+    return new FakeRequest(undefined);
+  }
+
+  clear(): FakeRequest<undefined> {
+    this.records.clear();
+    return new FakeRequest(undefined);
+  }
+
+  get(key: IDBValidKey): FakeRequest<unknown> {
+    return new FakeRequest(this.records.get(String(key)));
+  }
+
+  getAll(): FakeRequest<unknown[]> {
+    return new FakeRequest(Array.from(this.records.values()));
+  }
+}
+
+export class FakeTransaction {
+  oncomplete: Resolve | null = null;
+  onabort: ((ev?: unknown) => void) | null = null;
+  onerror: ((ev?: unknown) => void) | null = null;
+  error: Error | null = null;
+
+  constructor(
+    private readonly database: FakeIndexedDb,
+    private readonly storeName: string,
+    private readonly fail: boolean,
+  ) {
+    microtask2(() => {
+      if (this.fail) {
+        this.error = new Error('fake transaction failure');
+        this.onerror?.(this);
+        this.onabort?.(this);
+        return;
+      }
+      this.oncomplete?.();
+    });
+  }
+
+  objectStore(name: string): FakeObjectStore {
+    if (name !== this.storeName) {
+      throw new Error(`fake idb: transaction opened for "${this.storeName}", not "${name}"`);
+    }
+    return this.database.getOrCreateStore(name);
+  }
+}
+
+export class FakeIndexedDb {
+  /** DOMStringList-like: the wrapper calls `.contains()` (browser IDB API). */
+  readonly objectStoreNames = new Set<string>() as Set<string> & { contains(name: string): boolean };
+
+  constructor() {
+    this.objectStoreNames.contains = (name: string) => this.objectStoreNames.has(name);
+  }
+
+  private readonly storeSpecs = new Map<string, string>();
+  private readonly records = new Map<string, Map<string, unknown>>();
+  /** Instrumentation per store: { put, delete } counters. */
+  readonly opCounts = new Map<string, { put: number; delete: number }>();
+  onclose: (() => void) | null = null;
+  onversionchange: (() => void) | null = null;
+
+  createObjectStore(name: string, options?: { keyPath?: string }) {
+    this.objectStoreNames.add(name);
+    this.storeSpecs.set(name, options?.keyPath ?? 'key');
+    return { name };
+  }
+
+  getOrCreateStore(name: string): FakeObjectStore {
+    if (!this.storeSpecs.has(name)) {
+      this.storeSpecs.set(name, 'key');
+      this.objectStoreNames.add(name);
+    }
+    if (!this.records.has(name)) this.records.set(name, new Map());
+    const spec = { name, keyPath: this.storeSpecs.get(name)! };
+    const store = new FakeObjectStore(spec, this.records.get(name)!);
+    const counts = this.opCounts.get(name) ?? { put: 0, delete: 0 };
+    // Aggregate counts lazily via proxy-free bookkeeping on each op.
+    const originalPut = store.put.bind(store);
+    store.put = (value: unknown) => {
+      counts.put += 1;
+      this.opCounts.set(name, counts);
+      return originalPut(value);
+    };
+    const originalDelete = store.delete.bind(store);
+    store.delete = (key: IDBValidKey) => {
+      counts.delete += 1;
+      this.opCounts.set(name, counts);
+      return originalDelete(key);
+    };
+    return store;
+  }
+
+  transaction(storeName: string, _mode?: string): FakeTransaction {
+    return new FakeTransaction(this, storeName, false);
+  }
+
+  close() {
+    this.onclose?.();
+  }
+
+  /** Direct read for assertions (bypasses the async wrapper). */
+  dumpStore(name: string): unknown[] {
+    return Array.from(this.records.get(name)?.values() ?? []);
+  }
+}
+
+export interface FakeIndexedDbHandle {
+  db: FakeIndexedDb;
+  openCount: number;
+  restore: () => void;
+}
+
+export function installFakeIndexedDb(options: { failOpen?: boolean; failOpenTimes?: number; onOperation?: (storeName: string, op: 'put' | 'delete') => void } = {}): FakeIndexedDbHandle {
+  const previous = (globalThis as { indexedDB?: IDBFactory }).indexedDB;
+  const handle: FakeIndexedDbHandle = {
+    db: new FakeIndexedDb(),
+    openCount: 0,
+    restore: () => {
+      (globalThis as { indexedDB?: IDBFactory }).indexedDB = previous;
+    },
+  };
+  if (options.onOperation) {
+    const onOperation = options.onOperation;
+    const originalGet = handle.db.getOrCreateStore.bind(handle.db);
+    handle.db.getOrCreateStore = (name: string) => {
+      const store = originalGet(name);
+      const originalPut = store.put.bind(store);
+      store.put = (value: unknown) => {
+        onOperation(name, 'put');
+        return originalPut(value);
+      };
+      const originalDelete = store.delete.bind(store);
+      store.delete = (key: IDBValidKey) => {
+        onOperation(name, 'delete');
+        return originalDelete(key);
+      };
+      return store;
+    };
+  }
+  (globalThis as { indexedDB?: unknown }).indexedDB = {
+    open(_name: string, _version: number) {
+      handle.openCount += 1;
+      if (options.failOpen) {
+        return new FakeRequest<IDBDatabase>(null as unknown as IDBDatabase, 'failure', new Error('fake open failure'));
+      }
+      if (options.failOpenTimes != null && handle.openCount <= options.failOpenTimes) {
+        // Fail only the first N opens, then recover (boot-retry scenarios).
+        return new FakeRequest<IDBDatabase>(null as unknown as IDBDatabase, 'failure', new Error('fake open failure'));
+      }
+      return new FakeRequest<IDBDatabase>(handle.db as unknown as IDBDatabase, 'upgrade');
+    },
+  };
+  return handle;
+}

application/state/testSupport/localStorage.ts

@@ -0,0 +1,18 @@
+/** Install isolated browser storage for hook tests, including Node without Web Storage. */
+export function installTestLocalStorage(): () => void {
+  const previous = Object.getOwnPropertyDescriptor(globalThis, 'localStorage');
+  const values = new Map<string, string>();
+  const storage: Storage = {
+    get length() { return values.size; },
+    clear: () => values.clear(),
+    getItem: key => values.get(String(key)) ?? null,
+    key: index => [...values.keys()][index] ?? null,
+    removeItem: key => { values.delete(String(key)); },
+    setItem: (key, value) => { values.set(String(key), String(value)); },
+  };
+  Object.defineProperty(globalThis, 'localStorage', { configurable: true, value: storage });
+  return () => {
+    if (previous) Object.defineProperty(globalThis, 'localStorage', previous);
+    else Reflect.deleteProperty(globalThis, 'localStorage');
+  };
+}

application/state/useAIChatStreaming.ts

@@ -127,6 +127,8 @@ export interface SendToCattyContext {
 }
 
 export interface SendToExternalContext {
+  scopeType?: 'terminal' | 'workspace' | 'global';
+  scopeTargetId?: string;
   existingSessionId?: string;
   updateExternalSessionId?: (sessionId: string, externalSessionId: string | undefined) => void;
   historyMessages?: Array<{ role: 'user' | 'assistant'; content: string }>;

application/state/useAISettingsState.ts

@@ -12,6 +12,7 @@ import {
   STORAGE_KEY_AI_COMMAND_TIMEOUT,
   STORAGE_KEY_AI_RESPONSE_IDLE_TIMEOUT,
   STORAGE_KEY_AI_MAX_ITERATIONS,
+  STORAGE_KEY_AI_SESSION_MESSAGE_CAP,
   STORAGE_KEY_AI_AGENT_MODEL_MAP,
   STORAGE_KEY_AI_AGENT_PROVIDER_MAP,
   STORAGE_KEY_AI_WEB_SEARCH,
@@ -34,6 +35,10 @@ import {
   normalizeResponseIdleTimeoutSeconds,
 } from '../../infrastructure/ai/types';
 import { removeProviderReferences } from './aiProviderCleanup';
+import {
+  DEFAULT_AI_SESSION_MESSAGE_CAP,
+  normalizeAiSessionMessageCap,
+} from '../../domain/aiSessionMessageCap';
 import { AI_STATE_CHANGED_EVENT, emitAIStateChanged } from './aiStateEvents';
 import { getAIBridge } from './aiStateSnapshots';
 import { useStoredBoolean } from './useStoredBoolean';
@@ -87,6 +92,12 @@ export function useAISettingsState() {
   const [maxIterations, setMaxIterationsRaw] = useState<number>(() =>
     localStorageAdapter.readNumber(STORAGE_KEY_AI_MAX_ITERATIONS) ?? 20
   );
+  const [aiSessionMessageCap, setAiSessionMessageCapRaw] = useState<number>(() =>
+    normalizeAiSessionMessageCap(
+      localStorageAdapter.readNumber(STORAGE_KEY_AI_SESSION_MESSAGE_CAP)
+        ?? DEFAULT_AI_SESSION_MESSAGE_CAP,
+    )
+  );
   const [webSearchConfig, setWebSearchConfigRaw] = useState<WebSearchConfig | null>(() =>
     localStorageAdapter.read<WebSearchConfig>(STORAGE_KEY_AI_WEB_SEARCH) ?? null
   );
@@ -197,6 +208,12 @@ export function useAISettingsState() {
     getAIBridge()?.aiMcpSetMaxIterations?.(value);
   }, []);
 
+  const setAiSessionMessageCap = useCallback((value: number) => {
+    const normalizedValue = normalizeAiSessionMessageCap(value);
+    setAiSessionMessageCapRaw(normalizedValue);
+    localStorageAdapter.writeNumber(STORAGE_KEY_AI_SESSION_MESSAGE_CAP, normalizedValue);
+  }, []);
+
   const setWebSearchConfig = useCallback((config: WebSearchConfig | null) => {
     setWebSearchConfigRaw(config);
     if (config) {
@@ -277,6 +294,14 @@ export function useAISettingsState() {
             getAIBridge()?.aiMcpSetMaxIterations?.(iters);
             break;
           }
+          case STORAGE_KEY_AI_SESSION_MESSAGE_CAP:
+            setAiSessionMessageCapRaw(
+              normalizeAiSessionMessageCap(
+                localStorageAdapter.readNumber(STORAGE_KEY_AI_SESSION_MESSAGE_CAP)
+                  ?? DEFAULT_AI_SESSION_MESSAGE_CAP,
+              ),
+            );
+            break;
           case STORAGE_KEY_AI_WEB_SEARCH:
             setWebSearchConfigRaw(localStorageAdapter.read<WebSearchConfig>(STORAGE_KEY_AI_WEB_SEARCH) ?? null);
             break;
@@ -340,6 +365,8 @@ export function useAISettingsState() {
     setResponseIdleTimeout,
     maxIterations,
     setMaxIterations,
+    aiSessionMessageCap,
+    setAiSessionMessageCap,
     webSearchConfig,
     setWebSearchConfig,
     quickMessages,
@@ -373,6 +400,8 @@ export function useAISettingsState() {
     setResponseIdleTimeout,
     maxIterations,
     setMaxIterations,
+    aiSessionMessageCap,
+    setAiSessionMessageCap,
     webSearchConfig,
     setWebSearchConfig,
     quickMessages,

application/state/useAIState.bootHydration.test.ts

@@ -0,0 +1,489 @@
+/**
+ * Boot-scenario regression tests for the IndexedDB migration review fixes
+ * (issue #4125 review): P1 maintenance gating and complete legacy migration,
+ * P2① baseline seeding after an IndexedDB failure,
+ * P2② pointer validation gated on hydration, P2③ disk-backup restore when
+ * IndexedDB stays unopenable, and P2④ adopting an intentional cross-window
+ * deletion.
+ */
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import React, { act } from 'react';
+import { createRoot } from 'react-dom/client';
+import { JSDOM } from 'jsdom';
+import type { AISession } from '../../infrastructure/ai/types';
+import {
+  STORAGE_KEY_AI_ACTIVE_SESSION_MAP,
+  STORAGE_KEY_AI_SESSIONS,
+  STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW,
+  STORAGE_KEY_AI_SESSIONS_OVERFLOW,
+} from '../../infrastructure/config/storageKeys';
+import { useAIState } from './useAIState';
+import { getAISessionsSnapshot } from './aiSessionsStore';
+import {
+  __flushIdbWritesForTests,
+  __resetAiSessionsHydrationForTests,
+  __resetBackupMirrorForTests,
+  __resetIdbPersistenceForTests,
+  getPersistedAiSessionsSnapshot,
+  flushBackupMirror,
+  latestAISessionsSnapshot,
+  setLatestAIActiveSessionMapSnapshot,
+  setLatestAIDraftsByScopeSnapshot,
+  setLatestAIPanelViewByScopeSnapshot,
+  setLatestAISessionsSnapshot,
+} from './aiStateSnapshots';
+import {
+  idbDeleteSessionIds,
+  AI_SESSIONS_META_MIGRATION_KEY,
+  idbPutSessions,
+  loadOrMigrateAiSessions,
+  openAiSessionsIdb,
+  resetAiSessionsIdbForTests,
+} from './aiSessionIdbStorage';
+import { installFakeIndexedDb } from './testSupport/fakeIndexedDb';
+
+function makeSession(id: string, updatedAt: number): AISession {
+  return {
+    id,
+    title: id,
+    agentId: 'catty',
+    scope: { type: 'global' },
+    messages: [],
+    createdAt: updatedAt,
+    updatedAt,
+  } as AISession;
+}
+
+function installDom() {
+  const dom = new JSDOM('<!doctype html><html><body></body></html>', { url: 'http://localhost' });
+  for (const name of ['window', 'document', 'localStorage', 'CustomEvent', 'Event'] as const) {
+    Object.defineProperty(globalThis, name, { configurable: true, value: name === 'window' ? dom.window : dom.window[name] });
+  }
+  Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', { configurable: true, value: true });
+  return dom;
+}
+
+interface Mounted {
+  ai: ReturnType<typeof useAIState>;
+  root: ReturnType<typeof createRoot>;
+  container: HTMLDivElement;
+}
+
+async function mountAiState(onMaintenance?: (ai: ReturnType<typeof useAIState>) => void): Promise<Mounted> {
+  const holder: { ai?: ReturnType<typeof useAIState> } = {};
+  function Maintenance({ ai }: { ai: ReturnType<typeof useAIState> }) {
+    const mountAi = React.useRef(ai);
+    React.useEffect(() => { onMaintenance?.(mountAi.current); }, []);
+    return null;
+  }
+  function Harness() {
+    holder.ai = useAIState();
+    return onMaintenance ? React.createElement(Maintenance, { ai: holder.ai }) : null;
+  }
+  const container = document.createElement('div');
+  document.body.appendChild(container);
+  const root = createRoot(container);
+  await act(async () => { root.render(React.createElement(Harness)); });
+  return { ai: holder.ai!, root, container };
+}
+
+async function unmount(mounted: Mounted, dom: JSDOM) {
+  await act(async () => { mounted.root.unmount(); });
+  mounted.container.remove();
+  dom.window.close();
+}
+
+function resetBootState() {
+  // Post-boot defaults first, then back to pending so every test starts
+  // from the pre-hydration state its own hook instance controls.
+  __resetIdbPersistenceForTests();
+  __resetAiSessionsHydrationForTests();
+  // Module-level snapshots leak across tests (the hook's initial state and
+  // the boot merge path read them) — reset to the cold-start state. The
+  // map snapshot must be null so the hook falls back to localStorage.
+  setLatestAISessionsSnapshot([]);
+  setLatestAIActiveSessionMapSnapshot(null as unknown as Record<string, string | null>);
+  setLatestAIDraftsByScopeSnapshot({});
+  setLatestAIPanelViewByScopeSnapshot({});
+}
+
+test.beforeEach(() => {
+  __resetBackupMirrorForTests();
+  resetBootState();
+});
+test.afterEach(() => { __resetBackupMirrorForTests(); });
+
+test('P1: deleting the last migrated chat with no legacy key never restores a stale disk backup', async () => {
+  const dom = installDom();
+  const idb = installFakeIndexedDb();
+  const deleted = makeSession('deleted-chat', 1);
+  await loadOrMigrateAiSessions(() => JSON.stringify([deleted]));
+  await idbDeleteSessionIds(await openAiSessionsIdb(), [deleted.id]);
+  let backupReads = 0;
+  const backupWrites: string[] = [];
+  Object.assign(dom.window, {
+    netcatty: {
+      aiSessionsBackupReadLatest: async () => {
+        backupReads += 1;
+        return { ok: true, json: JSON.stringify([deleted]) };
+      },
+      aiSessionsBackupWrite: async ({ json }: { json: string }) => {
+        backupWrites.push(json);
+        return { ok: true };
+      },
+    },
+  });
+  const mounted = await mountAiState();
+  try {
+    flushBackupMirror();
+    await __flushIdbWritesForTests();
+    assert.equal(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS), null);
+    assert.equal(backupReads, 0);
+    assert.deepEqual(backupWrites, []);
+    assert.deepEqual(getAISessionsSnapshot().sessions, []);
+    assert.deepEqual(idb.db.dumpStore('sessions'), []);
+  } finally {
+    await unmount(mounted, dom);
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('P1: an uninitialized IndexedDB still restores the disk backup', async () => {
+  const dom = installDom();
+  const idb = installFakeIndexedDb();
+  const backup = [makeSession('backup-chat', 1)];
+  Object.assign(dom.window, {
+    netcatty: { aiSessionsBackupReadLatest: async () => ({ ok: true, json: JSON.stringify(backup) }) },
+  });
+  const mounted = await mountAiState();
+  try {
+    await __flushIdbWritesForTests();
+    assert.deepEqual(getAISessionsSnapshot().sessions, backup);
+    assert.deepEqual(idb.db.dumpStore('sessions'), backup);
+  } finally {
+    await unmount(mounted, dom);
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+for (const failure of ['not-ok', 'rejection', 'missing-id'] as const) {
+  test(`P1: disk overflow ${failure} keeps migration pending and backups intact, then retries beside primary IDB records`, async () => {
+    const dom = installDom();
+    const idb = installFakeIndexedDb();
+    const primary = makeSession('primary-chat', 3);
+    const chunk = makeSession('chunk-chat', 2);
+    const diskOnly = makeSession('disk-only-chat', 1);
+    const unmarked = makeSession('unmarked-deleted-chat', 0);
+    dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, JSON.stringify([primary]));
+    dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS_OVERFLOW, JSON.stringify([chunk]));
+    dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW, JSON.stringify([diskOnly.id]));
+    let recoveryAvailable = false;
+    let backupReads = 0;
+    const backupWrites: string[] = [];
+    Object.assign(dom.window, {
+      netcatty: {
+        aiSessionsBackupReadLatest: async () => {
+          backupReads += 1;
+          if (recoveryAvailable) return { ok: true, json: JSON.stringify([primary, chunk, diskOnly, unmarked]) };
+          if (failure === 'rejection') throw new Error('disk temporarily unavailable');
+          if (failure === 'missing-id') return { ok: true, json: JSON.stringify([unmarked]) };
+          return { ok: false };
+        },
+        aiSessionsBackupWrite: async ({ json }: { json: string }) => {
+          backupWrites.push(json);
+          return { ok: true };
+        },
+      },
+    });
+    let mounted = await mountAiState();
+    const hasMarker = () => idb.db.dumpStore('meta').some(entry => (entry as { key: string }).key === AI_SESSIONS_META_MIGRATION_KEY);
+    try {
+      assert.equal(backupReads, 1);
+      assert.equal(hasMarker(), false);
+      assert.deepEqual(getAISessionsSnapshot().sessions, [primary, chunk]);
+      assert.deepEqual(idb.db.dumpStore('sessions'), [primary, chunk]);
+      flushBackupMirror();
+      assert.deepEqual(backupWrites, [], 'boot must not mirror a partial migration');
+
+      // Ordinary edits and unload must also preserve the recovery generation.
+      await act(async () => {
+        mounted.ai.addMessageToSession(primary.id, { id: 'new-message', role: 'user', content: 'New edit', timestamp: 4 });
+      });
+      await new Promise(resolve => setTimeout(resolve, 600));
+      await __flushIdbWritesForTests();
+      dom.window.dispatchEvent(new dom.window.Event('beforeunload'));
+      assert.deepEqual(backupWrites, []);
+      const updated = getAISessionsSnapshot().sessions.find(session => session.id === primary.id)!;
+      assert.equal(updated.messages.length, 1);
+      assert.equal(hasMarker(), false);
+
+      await act(async () => { mounted.root.unmount(); });
+      mounted.container.remove();
+      resetBootState();
+      recoveryAvailable = true;
+      mounted = await mountAiState();
+      await __flushIdbWritesForTests();
+      assert.equal(backupReads, 2, 'populated IDB must still retry unresolved disk IDs');
+      assert.equal(hasMarker(), true);
+      const expected = [updated, chunk, diskOnly];
+      assert.deepEqual(getAISessionsSnapshot().sessions, expected);
+      assert.deepEqual(idb.db.dumpStore('sessions'), expected);
+      flushBackupMirror();
+      assert.equal(backupWrites.length, 1, 'mirroring resumes only after all marked IDs are recovered');
+      assert.deepEqual(JSON.parse(backupWrites[0]), expected);
+    } finally {
+      await unmount(mounted, dom);
+      idb.restore();
+      resetAiSessionsIdbForTests();
+    }
+  });
+}
+
+test('P1: child mount maintenance waits for hydration and marks the IndexedDB transcript dangling', async () => {
+  const dom = installDom();
+  const idb = installFakeIndexedDb();
+  const stale: AISession = {
+    ...makeSession('closed-chat', 1),
+    scope: { type: 'terminal', targetId: 'closed-terminal' },
+    messages: [{ id: 'm-1', role: 'user', content: 'Old history', timestamp: 1 }],
+  };
+  const current: AISession = {
+    ...stale,
+    updatedAt: 2,
+    messages: [...stale.messages, { id: 'm-2', role: 'assistant', content: 'New history', timestamp: 2 }],
+  };
+  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, JSON.stringify([stale]));
+  await idbPutSessions(await openAiSessionsIdb(), [current]);
+  setLatestAISessionsSnapshot(null as unknown as AISession[]);
+  let snapshotAfterMaintenance: AISession[] | null | undefined;
+  let putsAfterMaintenance = 0;
+  const mounted = await mountAiState((ai) => {
+    ai.cleanupOrphanedSessions(new Set(['live-terminal']));
+    snapshotAfterMaintenance = latestAISessionsSnapshot;
+    putsAfterMaintenance = idb.db.opCounts.get('sessions')!.put;
+  });
+  try {
+    assert.equal(snapshotAfterMaintenance, null, 'pending maintenance must not adopt the legacy transcript');
+    assert.equal(putsAfterMaintenance, 1, 'pending maintenance must not persist stale history');
+    await __flushIdbWritesForTests();
+    const expected = [{ ...current, scopeDangling: true }];
+    assert.deepEqual(getAISessionsSnapshot().sessions, expected);
+    assert.deepEqual(idb.db.dumpStore('sessions'), expected);
+    assert.equal(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS), JSON.stringify([stale]));
+  } finally {
+    await unmount(mounted, dom);
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('P1: migration includes chunked overflow alongside a populated primary', async () => {
+  const dom = installDom();
+  const idb = installFakeIndexedDb();
+  const primary = makeSession('primary-chat', 3);
+  const overflow = [makeSession('overflow-a', 2), makeSession('overflow-b', 1), { ...primary, updatedAt: 0 }];
+  const overflowJson = JSON.stringify(overflow);
+  const split = Math.floor(overflowJson.length / 2);
+  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, JSON.stringify([primary]));
+  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS_OVERFLOW, overflowJson.slice(0, split));
+  dom.window.localStorage.setItem(`${STORAGE_KEY_AI_SESSIONS_OVERFLOW}_2`, overflowJson.slice(split));
+  const mounted = await mountAiState();
+  try {
+    const expected = [primary, ...overflow.slice(0, 2)];
+    assert.deepEqual(getAISessionsSnapshot().sessions, expected);
+    assert.deepEqual(idb.db.dumpStore('sessions'), expected);
+    assert.ok(idb.db.dumpStore('meta').some((entry) => (entry as { key: string }).key === AI_SESSIONS_META_MIGRATION_KEY));
+    assert.equal(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS_OVERFLOW), overflowJson.slice(0, split));
+    assert.equal(dom.window.localStorage.getItem(`${STORAGE_KEY_AI_SESSIONS_OVERFLOW}_2`), overflowJson.slice(split));
+  } finally {
+    await unmount(mounted, dom);
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('P1: migration awaits disk-only recovery before recording completion beside a populated primary', async () => {
+  const dom = installDom();
+  const idb = installFakeIndexedDb();
+  const primary = makeSession('primary-chat', 3);
+  const diskOnly = makeSession('disk-only-chat', 2);
+  const deleted = makeSession('deleted-chat', 1);
+  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, JSON.stringify([primary]));
+  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW, JSON.stringify([diskOnly.id]));
+  let resolveBackup!: (result: { ok: boolean; json: string }) => void;
+  const backup = new Promise<{ ok: boolean; json: string }>((resolve) => { resolveBackup = resolve; });
+  let backupReads = 0;
+  Object.assign(dom.window, {
+    netcatty: { aiSessionsBackupReadLatest: () => { backupReads += 1; return backup; } },
+  });
+  const mounted = await mountAiState();
+  try {
+    assert.equal(backupReads, 1);
+    assert.equal(idb.db.dumpStore('meta').some((entry) => (entry as { key: string }).key === AI_SESSIONS_META_MIGRATION_KEY), false);
+    await act(async () => {
+      resolveBackup({ ok: true, json: JSON.stringify([primary, diskOnly, deleted]) });
+    });
+    assert.deepEqual(getAISessionsSnapshot().sessions, [primary, diskOnly]);
+    assert.deepEqual(idb.db.dumpStore('sessions'), [primary, diskOnly]);
+    assert.ok(idb.db.dumpStore('meta').some((entry) => (entry as { key: string }).key === AI_SESSIONS_META_MIGRATION_KEY));
+    assert.equal(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW), JSON.stringify([diskOnly.id]));
+  } finally {
+    await unmount(mounted, dom);
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+// ── P2①: idbFailed boot must persist the legacy set before seeding the baseline ──
+
+test('P2①a: after a transient IndexedDB open failure the legacy sessions are persisted and the baseline seeded', async () => {
+  const dom = installDom();
+  const idb = installFakeIndexedDb({ failOpenTimes: 1 });
+  const legacy = [makeSession('chat-a', 2), makeSession('chat-b', 1)];
+  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, JSON.stringify(legacy));
+  const mounted = await mountAiState();
+  try {
+    // One open retry happened inside the boot effect: the legacy set now
+    // lives in IndexedDB (old code never retried and left the store empty).
+    const ids = idb.db.dumpStore('sessions').map((s) => (s as AISession).id).sort();
+    assert.deepEqual(ids, ['chat-a', 'chat-b']);
+    assert.deepEqual(
+      getPersistedAiSessionsSnapshot().map((s) => s.id).sort(),
+      ['chat-a', 'chat-b'],
+    );
+    assert.deepEqual(getAISessionsSnapshot().sessions.map((s) => s.id).sort(), ['chat-a', 'chat-b']);
+  } finally {
+    await unmount(mounted, dom);
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+test('P2①b: with IndexedDB unreachable the baseline stays unset, so a later edit rewrites every record', async () => {
+  const dom = installDom();
+  const failing = installFakeIndexedDb({ failOpen: true });
+  const legacy = [makeSession('chat-a', 2), makeSession('chat-b', 1)];
+  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, JSON.stringify(legacy));
+  const mounted = await mountAiState();
+  let recovered: ReturnType<typeof installFakeIndexedDb> | null = null;
+  try {
+    // The retry open also failed: nothing was persisted, and the diff
+    // baseline must remain unset.
+    assert.deepEqual(failing.db.dumpStore('sessions'), []);
+
+    // IndexedDB recovers, then the user edits ONE session. The full set
+    // must reach the store, not only the edited record.
+    failing.restore();
+    resetAiSessionsIdbForTests();
+    recovered = installFakeIndexedDb();
+    await act(async () => {
+      mounted.ai.addMessageToSession('chat-a', { id: 'm-1', role: 'user', content: 'Edited', timestamp: 3 });
+    });
+    await new Promise((resolve) => setTimeout(resolve, 600)); // debounced persist
+    await act(async () => {});
+    await __flushIdbWritesForTests();
+    const ids = recovered.db.dumpStore('sessions').map((s) => (s as AISession).id).sort();
+    assert.deepEqual(ids, ['chat-a', 'chat-b']);
+  } finally {
+    await unmount(mounted, dom);
+    if (recovered) recovered.restore();
+    resetAiSessionsIdbForTests();
+  }
+});
+
+// ── P2②: pointer validation waits for hydration ──
+
+test('P2②: pointers survive cold mount before hydration and stay valid after the boot load', async () => {
+  const dom = installDom();
+  const source = makeSession('chat-1', 1);
+  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, JSON.stringify([source]));
+  dom.window.localStorage.setItem(
+    STORAGE_KEY_AI_ACTIVE_SESSION_MAP,
+    JSON.stringify({ 'terminal:t1': 'chat-1' }),
+  );
+  const mounted = await mountAiState();
+  try {
+    // Old code nulled the pointer here: the validation effect ran against
+    // the initially-empty in-memory session array.
+    assert.equal(getAISessionsSnapshot().activeSessionIdMap['terminal:t1'], 'chat-1');
+    assert.equal(
+      JSON.parse(dom.window.localStorage.getItem(STORAGE_KEY_AI_ACTIVE_SESSION_MAP)!)['terminal:t1'],
+      'chat-1',
+    );
+    // After hydration the session is restored and the pointer is intact.
+    await act(async () => {});
+    assert.deepEqual(getAISessionsSnapshot().sessions.map((s) => s.id), ['chat-1']);
+    assert.equal(getAISessionsSnapshot().activeSessionIdMap['terminal:t1'], 'chat-1');
+  } finally {
+    await unmount(mounted, dom);
+  }
+});
+
+// ── P2③: unopenable IndexedDB + corrupt legacy → disk backup is applied ──
+
+test('P2③: with IndexedDB unopenable and the legacy store corrupt the newest disk backup generation is applied', async () => {
+  const dom = installDom();
+  installFakeIndexedDb({ failOpen: true });
+  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, 'not-json'); // corrupt legacy
+  const backup = [makeSession('backup-chat', 5)];
+  const warns: unknown[][] = [];
+  const originalWarn = console.warn;
+  console.warn = (...args: unknown[]) => { warns.push(args); };
+  try {
+    Object.assign(dom.window, {
+      netcatty: { aiSessionsBackupReadLatest: async () => ({ ok: true, json: JSON.stringify(backup) }) },
+    });
+    const mounted = await mountAiState();
+    try {
+      await act(async () => {});
+      // The backup generation became the recovery source (old code: the
+      // failing IndexedDB recheck rejection was swallowed and the restore
+      // never ran).
+      assert.deepEqual(getAISessionsSnapshot().sessions.map((s) => s.id), ['backup-chat']);
+      assert.deepEqual(getPersistedAiSessionsSnapshot().map((s) => s.id), ['backup-chat']);
+      // The unopenable-store error was surfaced, not swallowed.
+      assert.ok(warns.some((args) => String(args[0]).includes('IndexedDB recheck failed')));
+    } finally {
+      await unmount(mounted, dom);
+    }
+  } finally {
+    console.warn = originalWarn;
+    delete (dom.window as unknown as { netcatty?: unknown }).netcatty;
+    resetAiSessionsIdbForTests();
+  }
+});
+
+// ── P2④: an empty getAll after hydration is an intentional deletion ──
+
+test('P2④: adopting an empty IndexedDB store after another window deleted the last chat', async () => {
+  const dom = installDom();
+  const idb = installFakeIndexedDb();
+  const source = makeSession('chat-1', 1);
+  await idbPutSessions(await openAiSessionsIdb(), [source]);
+  const mounted = await mountAiState();
+  try {
+    await act(async () => {});
+    assert.deepEqual(getAISessionsSnapshot().sessions.map((s) => s.id), ['chat-1']);
+    // Another window deletes the last chat and announces the change. The
+    // announcement must come from a second BroadcastChannel: a channel never
+    // delivers to itself (the module-level channel is the receiving window).
+    await idbDeleteSessionIds(await openAiSessionsIdb(), ['chat-1']);
+    const otherWindow = new BroadcastChannel('netcatty_ai_sessions_changed');
+    await act(async () => {
+      otherWindow.postMessage(Date.now());
+      await new Promise((resolve) => setTimeout(resolve, 25));
+    });
+    otherWindow.close();
+    // Old code early-returned on the empty getAll and kept the deleted
+    // session alive locally.
+    assert.deepEqual(getAISessionsSnapshot().sessions, []);
+    assert.deepEqual(getPersistedAiSessionsSnapshot(), []);
+  } finally {
+    await unmount(mounted, dom);
+    idb.restore();
+    resetAiSessionsIdbForTests();
+  }
+});

application/state/useAIState.fork.test.ts

@@ -8,7 +8,7 @@ import type { AISession } from '../../infrastructure/ai/types.ts';
 import { getAgentRuntime } from '../../infrastructure/ai/harness/globalAgentRuntime.ts';
 import { useAIState } from './useAIState.ts';
 import { useAISessionsStore } from './aiSessionsStore.ts';
-import { setLatestAISessionsSnapshot } from './aiStateSnapshots.ts';
+import { getPersistedAiSessionsSnapshot, setLatestAISessionsSnapshot } from './aiStateSnapshots.ts';
 
 const SOURCE_SESSION: AISession = {
   id: 'chat-source',
@@ -121,11 +121,18 @@ for (const newerCount of [49, 50]) {
     let branch: AISession | null = null;
     await act(async () => { branch = await capture.ai!.forkSessionFromMessage(SOURCE_SESSION.id, 'assistant-1'); });
     assert.ok(branch);
-    const saved: AISession[] = JSON.parse(dom.window.localStorage.getItem('netcatty_ai_sessions_v1')!);
-    assert.equal(saved.length, 50);
+    // Issue #4123: the persisted set lives in IndexedDB (count cap 1000, so
+    // nothing is evicted at these sizes) — not in a 50-capped localStorage
+    // blob.
+    const saved: AISession[] = getPersistedAiSessionsSnapshot();
+    assert.equal(saved.length, newerCount + 2);
     assert.deepEqual(saved.find(item => item.id === SOURCE_SESSION.id)?.messages, SOURCE_SESSION.messages);
     assert.deepEqual(saved.find(item => item.id === branch!.id)?.messages, SOURCE_SESSION.messages.slice(0, 2));
-    await act(async () => root.unmount()); container.remove(); dom.window.close();
+    await act(async () => root.unmount()); container.remove();
+    // Reload from the read-only legacy store (the stand-in for what the
+    // migration persists on a profile without IndexedDB).
+    dom.window.localStorage.setItem('netcatty_ai_sessions_v1', JSON.stringify(saved));
+    dom.window.close();
     const reloaded = await setupAiState(saved);
     assert.equal(reloaded.capture.sessions.find(item => item.id === SOURCE_SESSION.id)?.messages.length, 4);
     assert.equal(reloaded.capture.sessions.find(item => item.id === branch!.id)?.messages.length, 2);

application/state/useAIState.historyRetention.test.ts

@@ -4,10 +4,10 @@ import React, { act } from 'react';
 import { createRoot } from 'react-dom/client';
 import { JSDOM } from 'jsdom';
 import type { AISession } from '../../infrastructure/ai/types';
-import { STORAGE_KEY_AI_ACTIVE_SESSION_MAP, STORAGE_KEY_AI_SESSIONS, STORAGE_KEY_AI_SESSIONS_OVERFLOW, STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW, STORAGE_KEY_CLOUD_SYNC_AI_SESSIONS } from '../../infrastructure/config/storageKeys';
+import { STORAGE_KEY_AI_SESSIONS, STORAGE_KEY_CLOUD_SYNC_AI_SESSIONS } from '../../infrastructure/config/storageKeys';
 import { useAIState } from './useAIState';
 import { useAISessionsStore } from './aiSessionsStore';
-import { __resetBackupMirrorForTests, flushBackupMirror, readSessionsFromStorage, setLatestAIActiveSessionMapSnapshot, setLatestAISessionsSnapshot, writeSessionsForStorage } from './aiStateSnapshots';
+import { setLatestAISessionsSnapshot } from './aiStateSnapshots';
 
 for (const enabled of [true, false]) {
   test(`appending to long history preserves the synced prefix (chat sync ${enabled})`, async () => {
@@ -54,403 +54,3 @@ for (const enabled of [true, false]) {
   });
 }
 
-test('startup and cross-window updates load overflow chats and mirror the merged history', async () => {
-  const dom = new JSDOM('<!doctype html><html><body></body></html>', { url: 'http://localhost' });
-  for (const name of ['window', 'document', 'localStorage', 'CustomEvent', 'Event'] as const) {
-    Object.defineProperty(globalThis, name, { configurable: true, value: name === 'window' ? dom.window : dom.window[name] });
-  }
-  Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', { configurable: true, value: true });
-  const primary: AISession = {
-    id: 'primary', title: 'Primary', agentId: 'catty', scope: { type: 'global' },
-    createdAt: 1, updatedAt: 2, messages: [],
-  };
-  const overflow = { ...primary, id: 'overflow', title: 'Overflow', updatedAt: 1 };
-  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, JSON.stringify([primary]));
-  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS_OVERFLOW, JSON.stringify([overflow]));
-  setLatestAISessionsSnapshot(null as unknown as AISession[]);
-  __resetBackupMirrorForTests();
-  const backups: string[] = [];
-  Object.assign(dom.window, { netcatty: { aiSessionsBackupWrite: async ({ json }: { json: string }) => {
-    backups.push(json);
-    return { ok: true };
-  } } });
-  let sessions: readonly AISession[] = [];
-  function Harness() {
-    useAIState();
-    sessions = useAISessionsStore().sessions;
-    return null;
-  }
-  const container = document.createElement('div');
-  document.body.appendChild(container);
-  const root = createRoot(container);
-  try {
-    await act(async () => { root.render(React.createElement(Harness)); });
-    assert.deepEqual(sessions, [primary, overflow]);
-    flushBackupMirror();
-    assert.deepEqual(JSON.parse(backups[0]), [primary, overflow]);
-    const updatedOverflow = { ...overflow, title: 'Updated elsewhere', updatedAt: 3 };
-    await act(async () => {
-      dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS_OVERFLOW, JSON.stringify([updatedOverflow]));
-      dom.window.dispatchEvent(new dom.window.StorageEvent('storage', { key: STORAGE_KEY_AI_SESSIONS_OVERFLOW }));
-    });
-    assert.deepEqual(sessions, [updatedOverflow, primary]);
-  } finally {
-    await act(async () => { root.unmount(); });
-    __resetBackupMirrorForTests();
-    setLatestAISessionsSnapshot([]);
-    container.remove();
-    dom.window.close();
-  }
-});
-
-for (const scopeType of ['global', 'terminal'] as const) {
-  test(`import retains disk-only chats in live history across rename and deletion (${scopeType})`, async () => {
-    const dom = new JSDOM('<!doctype html><html><body></body></html>', {
-      url: 'http://localhost', storageQuota: 5 * 1024 * 1024,
-    });
-    const previousDOMException = globalThis.DOMException;
-    for (const name of ['window', 'document', 'localStorage', 'CustomEvent', 'Event', 'DOMException'] as const) {
-      Object.defineProperty(globalThis, name, { configurable: true, value: name === 'window' ? dom.window : dom.window[name] });
-    }
-    Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', { configurable: true, value: true });
-    const source: AISession[] = Array.from({ length: 6 }, (_, index) => ({
-      id: `imported-${index}`, title: `Imported ${index}`, agentId: 'catty',
-      scope: scopeType === 'global' ? { type: 'global' } : { type: 'terminal', targetId: 'closed-terminal' },
-      createdAt: 1, updatedAt: 6 - index,
-      messages: [{ id: 'm', role: 'user', content: 'x'.repeat(Math.floor(1.1 * 1024 * 1024)), timestamp: 1 }],
-    }));
-    const ids = source.map(session => session.id);
-    const backups: string[] = [];
-    Object.assign(dom.window, { netcatty: {
-      aiSessionsBackupImport: async () => ({ success: true, json: JSON.stringify(source) }),
-      aiSessionsBackupWrite: async ({ json }: { json: string }) => { backups.push(json); return { ok: true }; },
-    } });
-    dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, '[]');
-    setLatestAISessionsSnapshot([]);
-    setLatestAIActiveSessionMapSnapshot({});
-    __resetBackupMirrorForTests();
-    let ai!: ReturnType<typeof useAIState>;
-    let sessions: readonly AISession[] = [];
-    function Harness() {
-      ai = useAIState();
-      sessions = useAISessionsStore().sessions;
-      return null;
-    }
-    const container = document.createElement('div');
-    document.body.appendChild(container);
-    const root = createRoot(container);
-    try {
-      await act(async () => { root.render(React.createElement(Harness)); });
-      await act(async () => { ai.cleanupOrphanedSessions(new Set()); });
-      let importedCount = 0;
-      await act(async () => { importedCount = await ai.importSessionsBackup(); });
-      assert.equal(importedCount, source.length);
-      assert.deepEqual(sessions.map(session => session.id), ids);
-      assert.deepEqual(readSessionsFromStorage().map(session => session.id), [ids[0]]);
-      assert.deepEqual(JSON.parse(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW)!), ids.slice(1));
-      assert.equal(sessions.every(session => !!session.scopeDangling === (scopeType === 'terminal')), true);
-      flushBackupMirror();
-      assert.deepEqual(JSON.parse(backups.at(-1)!), sessions);
-
-      await act(async () => { ai.updateSessionTitle(ids[0], 'Renamed after import'); });
-      assert.deepEqual(sessions.map(session => session.id), ids);
-      assert.equal(sessions[0].title, 'Renamed after import');
-      assert.deepEqual(JSON.parse(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW)!), ids.slice(1));
-      flushBackupMirror();
-      assert.deepEqual(JSON.parse(backups.at(-1)!), sessions);
-
-      await act(async () => { ai.deleteSession(ids[5]); });
-      assert.deepEqual(sessions.map(session => session.id), ids.slice(0, 5));
-      assert.deepEqual(JSON.parse(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW)!), ids.slice(1, 5));
-      flushBackupMirror();
-      assert.deepEqual(JSON.parse(backups.at(-1)!), sessions);
-    } finally {
-      await act(async () => { root.unmount(); });
-      __resetBackupMirrorForTests();
-      setLatestAISessionsSnapshot([]);
-      setLatestAIActiveSessionMapSnapshot({});
-      container.remove();
-      dom.window.close();
-      Object.defineProperty(globalThis, 'DOMException', { configurable: true, value: previousDOMException });
-    }
-  });
-}
-
-test('startup recovers disk-only chats before mirroring a valid partial primary', async () => {
-  const dom = new JSDOM('<!doctype html><html><body></body></html>', {
-    url: 'http://localhost', storageQuota: 5 * 1024 * 1024,
-  });
-  const previousDOMException = globalThis.DOMException;
-  for (const name of ['window', 'document', 'localStorage', 'CustomEvent', 'Event', 'DOMException'] as const) {
-    Object.defineProperty(globalThis, name, { configurable: true, value: name === 'window' ? dom.window : dom.window[name] });
-  }
-  Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', { configurable: true, value: true });
-  const source: AISession[] = Array.from({ length: 6 }, (_, index) => ({
-    id: `chat-${index}`, title: `Chat ${index}`, agentId: 'catty', scope: { type: 'global' },
-    createdAt: 1, updatedAt: 6 - index,
-    messages: [{ id: 'm', role: 'user', content: 'x'.repeat(Math.floor(1.1 * 1024 * 1024)), timestamp: 1 }],
-  }));
-  const backups: string[] = [];
-  let reads = 0;
-  let resolveRead!: (backup: { ok: boolean; json: string }) => void;
-  Object.assign(dom.window, { netcatty: {
-    aiSessionsBackupWrite: async ({ json }: { json: string }) => { backups.push(json); return { ok: true }; },
-    aiSessionsBackupReadLatest: () => {
-      reads += 1;
-      return new Promise(resolve => { resolveRead = resolve; });
-    },
-  } });
-  __resetBackupMirrorForTests();
-  assert.equal(writeSessionsForStorage(source), true);
-  flushBackupMirror();
-  assert.deepEqual(JSON.parse(backups[0]), source);
-  assert.deepEqual(readSessionsFromStorage(), [source[0]]);
-  assert.deepEqual(JSON.parse(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW)!), source.slice(1).map(session => session.id));
-  // A newer local copy must win, and an old deleted chat in the backup must
-  // stay deleted: only the explicitly recorded disk-only IDs are recovered.
-  const primary = { ...source[0], title: 'Newer primary', updatedAt: 10 };
-  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, JSON.stringify([primary]));
-  const expected = [primary, ...source.slice(1)];
-  const staleBackup = JSON.stringify([...source, { ...source[5], id: 'deleted-chat' }]);
-  backups.length = 0;
-  __resetBackupMirrorForTests();
-  setLatestAISessionsSnapshot(null as unknown as AISession[]);
-  let sessions: readonly AISession[] = [];
-  function Harness() {
-    useAIState();
-    sessions = useAISessionsStore().sessions;
-    return null;
-  }
-  const container = document.createElement('div');
-  document.body.appendChild(container);
-  const root = createRoot(container);
-  try {
-    await act(async () => { root.render(React.createElement(Harness)); });
-    assert.equal(reads, 1);
-    flushBackupMirror();
-    assert.deepEqual(backups, []);
-    await act(async () => { resolveRead({ ok: true, json: staleBackup }); });
-    assert.deepEqual(sessions, expected);
-    flushBackupMirror();
-    assert.deepEqual(JSON.parse(backups.at(-1)!), expected);
-    assert.deepEqual(readSessionsFromStorage(), [primary]);
-  } finally {
-    await act(async () => { root.unmount(); });
-    __resetBackupMirrorForTests();
-    setLatestAISessionsSnapshot([]);
-    container.remove();
-    dom.window.close();
-    Object.defineProperty(globalThis, 'DOMException', { configurable: true, value: previousDOMException });
-  }
-});
-
-for (const scopeType of ['terminal', 'workspace'] as const) {
-  test(`startup orphan cleanup preserves pending disk-only recovery (${scopeType})`, async () => {
-    const dom = new JSDOM('<!doctype html><html><body></body></html>', { url: 'http://localhost' });
-    for (const name of ['window', 'document', 'localStorage', 'CustomEvent', 'Event'] as const) {
-      Object.defineProperty(globalThis, name, { configurable: true, value: name === 'window' ? dom.window : dom.window[name] });
-    }
-    Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', { configurable: true, value: true });
-    const primary: AISession = {
-      id: 'closed-primary', title: 'Closed primary', agentId: 'catty',
-      scope: { type: scopeType, targetId: 'closed-target' },
-      createdAt: 1, updatedAt: 2, messages: [],
-    };
-    const diskOnly: AISession = {
-      ...primary, id: 'disk-only', title: 'Disk only', updatedAt: 1,
-      scope: { type: scopeType, targetId: 'another-closed-target' },
-    };
-    dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, JSON.stringify([primary]));
-    dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW, JSON.stringify([diskOnly.id]));
-    setLatestAISessionsSnapshot(null as unknown as AISession[]);
-    __resetBackupMirrorForTests();
-    const backups: string[] = [];
-    let reads = 0;
-    let resolveRead!: (backup: { ok: boolean; json: string }) => void;
-    Object.assign(dom.window, { netcatty: {
-      aiSessionsBackupWrite: async ({ json }: { json: string }) => { backups.push(json); return { ok: true }; },
-      aiSessionsBackupReadLatest: () => {
-        reads += 1;
-        return new Promise(resolve => { resolveRead = resolve; });
-      },
-    } });
-    let sessions: readonly AISession[] = [];
-    function Harness() {
-      const ai = useAIState();
-      sessions = useAISessionsStore().sessions;
-      // TerminalLayerSupport performs this cleanup on mount, while the disk
-      // backup IPC read can still be pending.
-      React.useEffect(() => { ai.cleanupOrphanedSessions(new Set()); }, [ai.cleanupOrphanedSessions]);
-      return null;
-    }
-    const container = document.createElement('div');
-    document.body.appendChild(container);
-    const root = createRoot(container);
-    try {
-      await act(async () => { root.render(React.createElement(Harness)); });
-      assert.equal(reads, 1);
-      assert.deepEqual(sessions, [{ ...primary, scopeDangling: true }]);
-      assert.deepEqual(JSON.parse(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW)!), [diskOnly.id]);
-      flushBackupMirror();
-      assert.deepEqual(backups, []);
-
-      await act(async () => { resolveRead({ ok: true, json: JSON.stringify([primary, diskOnly]) }); });
-      const expected = [primary, diskOnly].map(session => ({ ...session, scopeDangling: true }));
-      assert.deepEqual(sessions, expected);
-      assert.deepEqual(readSessionsFromStorage(), expected);
-      assert.equal(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW), null);
-      flushBackupMirror();
-      assert.deepEqual(JSON.parse(backups.at(-1)!), expected);
-    } finally {
-      await act(async () => { root.unmount(); });
-      __resetBackupMirrorForTests();
-      setLatestAISessionsSnapshot([]);
-      container.remove();
-      dom.window.close();
-    }
-  });
-}
-
-for (const mutation of ['rename', 'create', 'delete', 'delete-pending'] as const) {
-  test(`live ${mutation} preserves intended history across pending disk recovery`, async () => {
-    const dom = new JSDOM('<!doctype html><html><body></body></html>', { url: 'http://localhost' });
-    for (const name of ['window', 'document', 'localStorage', 'CustomEvent', 'Event'] as const) {
-      Object.defineProperty(globalThis, name, { configurable: true, value: name === 'window' ? dom.window : dom.window[name] });
-    }
-    Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', { configurable: true, value: true });
-    const primary: AISession = {
-      id: 'primary', title: 'Primary', agentId: 'catty', scope: { type: 'global' },
-      createdAt: 1, updatedAt: 2, messages: [],
-    };
-    const diskOnly = { ...primary, id: 'disk-only', updatedAt: 1 };
-    dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, JSON.stringify([primary]));
-    dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW, JSON.stringify([diskOnly.id]));
-    dom.window.localStorage.setItem(STORAGE_KEY_AI_ACTIVE_SESSION_MAP, JSON.stringify({ 'global:': diskOnly.id }));
-    setLatestAIActiveSessionMapSnapshot({ 'global:': diskOnly.id });
-    setLatestAISessionsSnapshot(null as unknown as AISession[]);
-    __resetBackupMirrorForTests();
-    const backups: string[] = [];
-    let resolveRead!: (backup: { ok: boolean; json: string }) => void;
-    Object.assign(dom.window, { netcatty: {
-      aiSessionsBackupWrite: async ({ json }: { json: string }) => { backups.push(json); return { ok: true }; },
-      aiSessionsBackupReadLatest: () => new Promise(resolve => { resolveRead = resolve; }),
-    } });
-    let ai!: ReturnType<typeof useAIState>;
-    let snapshot!: ReturnType<typeof useAISessionsStore>;
-    function Harness() {
-      ai = useAIState();
-      snapshot = useAISessionsStore();
-      return null;
-    }
-    const container = document.createElement('div');
-    document.body.appendChild(container);
-    const root = createRoot(container);
-    try {
-      await act(async () => { root.render(React.createElement(Harness)); });
-      assert.equal(snapshot.activeSessionIdMap['global:'], diskOnly.id);
-      await act(async () => {
-        if (mutation === 'rename') ai.updateSessionTitle(primary.id, 'Renamed before recovery');
-        else if (mutation === 'create') ai.createSession({ type: 'global' }, 'catty');
-        else ai.deleteSession(mutation === 'delete-pending' ? diskOnly.id : primary.id);
-      });
-      const liveBeforeRecovery = [...snapshot.sessions];
-      const expectedActiveId = mutation === 'create' ? liveBeforeRecovery[0].id
-        : mutation === 'delete-pending' ? null : diskOnly.id;
-      assert.equal(snapshot.activeSessionIdMap['global:'], expectedActiveId);
-      assert.deepEqual(readSessionsFromStorage(), liveBeforeRecovery);
-      const recoveryMarker = dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW);
-      assert.deepEqual(recoveryMarker == null ? null : JSON.parse(recoveryMarker), mutation === 'delete-pending' ? null : [diskOnly.id]);
-      flushBackupMirror();
-      assert.deepEqual(backups.map(json => JSON.parse(json)), mutation === 'delete-pending' ? [liveBeforeRecovery] : []);
-
-      await act(async () => { resolveRead({ ok: true, json: JSON.stringify([primary, diskOnly]) }); });
-      const expected = mutation === 'delete-pending' ? liveBeforeRecovery : [...liveBeforeRecovery, diskOnly];
-      assert.deepEqual(snapshot.sessions, expected);
-      assert.deepEqual(readSessionsFromStorage(), expected);
-      assert.equal(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW), null);
-      flushBackupMirror();
-      assert.deepEqual(JSON.parse(backups.at(-1)!), expected);
-    } finally {
-      await act(async () => { root.unmount(); });
-      __resetBackupMirrorForTests();
-      setLatestAISessionsSnapshot([]);
-      setLatestAIActiveSessionMapSnapshot({});
-      container.remove();
-      dom.window.close();
-    }
-  });
-}
-
-test('count-cap eviction clears a loaded disk-only marker and resumes backup mirroring', () => {
-  const dom = new JSDOM('<!doctype html><html><body></body></html>', { url: 'http://localhost' });
-  for (const name of ['window', 'document', 'localStorage', 'CustomEvent', 'Event'] as const) {
-    Object.defineProperty(globalThis, name, { configurable: true, value: name === 'window' ? dom.window : dom.window[name] });
-  }
-  const source: AISession[] = Array.from({ length: 51 }, (_, index) => ({
-    id: `chat-${index}`, title: `Chat ${index}`, agentId: 'catty', scope: { type: 'global' },
-    createdAt: 1, updatedAt: 51 - index, messages: [],
-  }));
-  dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW, JSON.stringify([source[50].id]));
-  const backups: string[] = [];
-  Object.assign(dom.window, { netcatty: { aiSessionsBackupWrite: async ({ json }: { json: string }) => {
-    backups.push(json);
-    return { ok: true };
-  } } });
-  __resetBackupMirrorForTests();
-  try {
-    assert.equal(writeSessionsForStorage(source), true);
-    assert.deepEqual(readSessionsFromStorage(), source.slice(0, 50));
-    assert.equal(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW), null);
-    flushBackupMirror();
-    assert.deepEqual(backups.map(json => JSON.parse(json)), [source.slice(0, 50)]);
-  } finally {
-    __resetBackupMirrorForTests();
-    dom.window.close();
-  }
-});
-
-for (const keepPrimary of [true, false]) {
-  test(`deletion clears disk-only recovery and remains authoritative (keep primary ${keepPrimary})`, async () => {
-    const dom = new JSDOM('<!doctype html><html><body></body></html>', { url: 'http://localhost' });
-    for (const name of ['window', 'document', 'localStorage', 'CustomEvent', 'Event'] as const) {
-      Object.defineProperty(globalThis, name, { configurable: true, value: name === 'window' ? dom.window : dom.window[name] });
-    }
-    Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', { configurable: true, value: true });
-    const primary: AISession = {
-      id: 'primary', title: 'Primary', agentId: 'catty', scope: { type: 'global' },
-      createdAt: 1, updatedAt: 2, messages: [],
-    };
-    dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS, JSON.stringify([primary]));
-    dom.window.localStorage.setItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW, JSON.stringify(['deleted-chat']));
-    const remaining = keepPrimary ? [primary] : [];
-    assert.equal(writeSessionsForStorage(remaining, { deletedSessionIds: ['deleted-chat'] }), true);
-    assert.equal(dom.window.localStorage.getItem(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW), null);
-    __resetBackupMirrorForTests();
-    setLatestAISessionsSnapshot(null as unknown as AISession[]);
-    let reads = 0;
-    Object.assign(dom.window, { netcatty: { aiSessionsBackupReadLatest: async () => {
-      reads += 1;
-      return { ok: true, json: JSON.stringify([primary, { ...primary, id: 'deleted-chat' }]) };
-    } } });
-    let sessions: readonly AISession[] = [];
-    function Harness() {
-      useAIState();
-      sessions = useAISessionsStore().sessions;
-      return null;
-    }
-    const container = document.createElement('div');
-    document.body.appendChild(container);
-    const root = createRoot(container);
-    try {
-      await act(async () => { root.render(React.createElement(Harness)); });
-      assert.equal(reads, 0);
-      assert.deepEqual(sessions, remaining);
-    } finally {
-      await act(async () => { root.unmount(); });
-      __resetBackupMirrorForTests();
-      setLatestAISessionsSnapshot([]);
-      container.remove();
-      dom.window.close();
-    }
-  });
-}

application/state/useAIState.ts

@@ -66,18 +66,23 @@ import {
   bumpDraftUploadGeneration,
   cleanupDeletedAIChatSessions,
   cleanupOrphanedAISessions,
-  latestAIActiveTargetIdsSnapshot,
-  getAIBridge,
   flushBackupMirror,
+  getAIBridge,
   getDraftUploadGeneration,
+  getPersistedAiSessionsSnapshot,
+  isAiSessionsHydrationComplete,
   latestAIActiveSessionMapSnapshot,
+  latestAIActiveTargetIdsSnapshot,
   latestAIDraftsByScopeSnapshot,
   latestAIPanelViewByScopeSnapshot,
   latestAISessionsSnapshot,
+  markAiSessionsHydrationComplete,
   prepareRestoredSessions,
-  readSessionsFromStorage,
-  scheduleBackupMirror,
+  readAiSessionMessageCap,
   rebindActiveSessionMap,
+  scheduleBackupMirror,
+  seedLastPersistedSessions,
+  setAiSessionsBackupRecoveryPending,
   writeSessionsForStorage,
   setLatestAIActiveSessionMapSnapshot,
   setLatestAIDraftsByScopeSnapshot,
@@ -86,11 +91,25 @@ import {
   type DraftsByScope,
   type PanelViewByScope,
 } from './aiStateSnapshots';
+import {
+  AI_SESSIONS_IDB_VERSION,
+  AI_SESSIONS_META_LAST_WRITE_KEY,
+  AI_SESSIONS_META_SCHEMA_VERSION_KEY,
+  idbGetAllSessions,
+  idbPutMeta,
+  idbPutSessions,
+  loadOrMigrateAiSessions,
+  mirrorActiveSessionMapToIdb,
+  openAiSessionsIdb,
+  publishAiSessionsIdbChange,
+  readActiveSessionMapFromIdb,
+  subscribeAiSessionsIdbChange,
+} from './aiSessionIdbStorage';
 import {
   isMissingOrCorruptSessionsStore,
-  parseSessionsStore,
   mergeImportedSessions,
   parseBackupSessions,
+  readLiveSessionsArray,
 } from './aiSessionsBackup';
 import { AI_STATE_CHANGED_EVENT, emitAIStateChanged } from './aiStateEvents';
 import {
@@ -181,53 +200,165 @@ export function useAIState() {
   );
 
   // ── Sessions ──
-  const [sessions, setSessionsRaw] = useState<AISession[]>(() =>
-    latestAISessionsSnapshot
-      ?? readSessionsFromStorage()
-  );
+  // Memory-only initial state: the primary store is IndexedDB and loads
+  // asynchronously in the boot effect below (issue #4123). The legacy
+  // localStorage key is read-only fallback and must not pre-seed stale data.
+  const [sessions, setSessionsRaw] = useState<AISession[]>(() => latestAISessionsSnapshot ?? []);
+  // Issue #4125 review P2②: flips true when the boot load settles. The
+  // active-pointer validation effect waits for it — the initially-empty
+  // in-memory session array must never null the persisted pointers.
+  const [sessionsHydrated, setSessionsHydrated] = useState(() => isAiSessionsHydrationComplete());
   // An explicit empty array is authoritative, even if the backup is stale.
-  // Disk-only overflow IDs also permit recovery, without reviving deleted chats.
+  // Only a missing or corrupt store can be restored from disk.
   useEffect(() => {
     window.addEventListener('beforeunload', flushBackupMirror);
     return () => window.removeEventListener('beforeunload', flushBackupMirror);
   }, []);
   useEffect(() => {
-    const liveRaw = localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS);
-    const liveStore = parseSessionsStore(liveRaw);
-    const liveSessions = readSessionsFromStorage();
-    const diskOnlyRecovery = (localStorageAdapter.read<string[]>(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW)?.length ?? 0) > 0;
-    if (!diskOnlyRecovery && (liveStore.valid || liveSessions.length > 0)) {
-      if (liveSessions.length > 0) scheduleBackupMirror(JSON.stringify(liveSessions));
-      return;
-    }
-    if (!diskOnlyRecovery && latestAISessionsSnapshot && latestAISessionsSnapshot.length > 0) return;
-    const bridge = getAIBridge();
-    if (!bridge?.aiSessionsBackupReadLatest) return;
     let cancelled = false;
-    const canRestore = () => diskOnlyRecovery
-      ? (localStorageAdapter.read<string[]>(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW)?.length ?? 0) > 0
-      : isMissingOrCorruptSessionsStore(localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS))
-        && readSessionsFromStorage().length === 0
-        && (latestAISessionsSnapshot?.length ?? 0) === 0
-        && sessionsRef.current.length === 0;
+    let cleanupAfterHydration = false;
     void (async () => {
       try {
-        if (!canRestore()) return;
+        // 1. IndexedDB (primary) → one-time legacy localStorage migration.
+        const diskOnlyIds = new Set(localStorageAdapter.read<string[]>(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW) ?? []);
+        setAiSessionsBackupRecoveryPending(diskOnlyIds.size > 0);
+        const boot = await loadOrMigrateAiSessions(
+          async () => {
+            // Legacy retention split history between the primary key, JSON
+            // chunks, and explicitly marked disk-only records. Resolve all
+            // slices before the one-shot migration records completion.
+            const chunks: string[] = [];
+            for (let index = 0; ; index += 1) {
+              const key = index === 0 ? STORAGE_KEY_AI_SESSIONS_OVERFLOW : `${STORAGE_KEY_AI_SESSIONS_OVERFLOW}_${index + 1}`;
+              const chunk = localStorageAdapter.readString(key);
+              if (chunk == null) break;
+              chunks.push(chunk);
+            }
+            let legacy = mergeImportedSessions(
+              readLiveSessionsArray(chunks.join('')),
+              readLiveSessionsArray(localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS)),
+            );
+            if (diskOnlyIds.size > 0) {
+              try {
+                const backup = await getAIBridge()?.aiSessionsBackupReadLatest?.();
+                if (backup?.ok) {
+                  legacy = mergeImportedSessions(
+                    (parseBackupSessions(backup.json) ?? []).filter(session => diskOnlyIds.has(session.id)),
+                    legacy,
+                  );
+                }
+              } catch (error) {
+                console.warn('[AIState] Disk-only session recovery failed; migration will retry on the next boot:', error);
+              }
+            }
+            return JSON.stringify(legacy);
+          },
+          [...diskOnlyIds],
+        );
+        setAiSessionsBackupRecoveryPending(boot.migrationPending);
+        if (cancelled) return;
+        if (boot.idbFailed && boot.sessions.length > 0) {
+          // Issue #4125 review P2①: the legacy set is not in IndexedDB yet.
+          // Persist it best-effort (one re-open retry) BEFORE seeding the
+          // diff baseline; if the store is still unreachable, leave the
+          // baseline unset so the next edit performs a full write instead of
+          // a diff that would drop the un-persisted sessions after IndexedDB
+          // recovers.
+          try {
+            const db = await openAiSessionsIdb();
+            if (!cancelled) {
+              await idbPutSessions(db, boot.sessions);
+              await idbPutMeta(db, AI_SESSIONS_META_SCHEMA_VERSION_KEY, AI_SESSIONS_IDB_VERSION);
+              await idbPutMeta(db, AI_SESSIONS_META_LAST_WRITE_KEY, Date.now());
+              publishAiSessionsIdbChange();
+              seedLastPersistedSessions(boot.sessions);
+            }
+          } catch (error) {
+            console.warn(
+              '[AIState] Could not persist the legacy sessions after an IndexedDB failure;'
+              + ' the diff baseline stays unset so the next edit rewrites every record:',
+              error,
+            );
+          }
+        } else {
+          seedLastPersistedSessions(boot.sessions);
+        }
+
+        // Restore the mirrored active-pointer map when the localStorage key
+        // is missing (fresh profile restored from IndexedDB).
+        if (localStorageAdapter.readString(STORAGE_KEY_AI_ACTIVE_SESSION_MAP) == null) {
+          const mirrored = await readActiveSessionMapFromIdb();
+          if (cancelled) return;
+          if (mirrored && Object.keys(mirrored).length > 0) {
+            localStorageAdapter.write(STORAGE_KEY_AI_ACTIVE_SESSION_MAP, mirrored);
+            setLatestAIActiveSessionMapSnapshot(mirrored);
+            setActiveSessionIdMapRaw(mirrored);
+          }
+        }
+
+        const bootSessions = boot.sessions;
+        if (bootSessions.length > 0) {
+          const live = latestAISessionsSnapshot ?? sessionsRef.current;
+          if (live.length > 0) {
+            // Sessions were created before the async load finished: merge
+            // (live records win by id) instead of clobbering either side.
+            const byId = new Map(bootSessions.map(session => [session.id, session]));
+            for (const session of live) byId.set(session.id, session);
+            const merged = Array.from(byId.values())
+              .sort((a, b) => (b.updatedAt ?? 0) - (a.updatedAt ?? 0));
+            setLatestAISessionsSnapshot(merged);
+            sessionsRef.current = merged;
+            setSessionsRaw(merged);
+            writeSessionsForStorage(merged);
+            return;
+          }
+          setLatestAISessionsSnapshot(bootSessions);
+          sessionsRef.current = bootSessions;
+          setSessionsRaw(bootSessions);
+          scheduleBackupMirror(JSON.stringify(bootSessions));
+          cleanupAfterHydration = true;
+          return;
+        }
+
+        // A previously initialized empty IDB is a committed deletion. An
+        // incomplete migration must retry only its marked disk-only records.
+        if (boot.authoritativeEmpty || boot.migrationPending) return;
+
+        // 2. Uninitialized store (and no legacy data to migrate): the #4018 disk
+        // backup remains the last restore step. Only when the legacy store
+        // is also missing or corrupt — a valid empty legacy array is an
+        // intentional wipe and stays authoritative.
+        if (!isMissingOrCorruptSessionsStore(localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS))) {
+          return;
+        }
+        const bridge = getAIBridge();
+        if (!bridge?.aiSessionsBackupReadLatest) return;
         const backup = await bridge.aiSessionsBackupReadLatest?.();
         if (cancelled || !backup?.ok) return;
-        // Re-check after the async gap so live mutations and deletions win.
-        if (!canRestore()) return;
-        const backupSessions = parseBackupSessions(backup.json);
-        if (!backupSessions) return;
-        const diskOnlyIds = new Set(localStorageAdapter.read<string[]>(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW) ?? []);
-        const recovered = diskOnlyRecovery
-          ? mergeImportedSessions(
-            backupSessions.filter(session => diskOnlyIds.has(session.id)),
-            latestAISessionsSnapshot ?? readSessionsFromStorage(),
-          )
-          : backupSessions;
+        // Re-check after the async gap: a session may have been created
+        // while the backup was being read; never restore over live state.
+        // Cover persisted storage and in-memory snapshot/React state —
+        // createSession updates the snapshot before the debounced disk write.
+        if ((latestAISessionsSnapshot?.length ?? 0) > 0) return;
+        if (sessionsRef.current.length > 0) return;
+        // Issue #4125 review P2③: one open retry already happened inside
+        // the boot load. If the store is still unopenable, do not let the
+        // recheck rejection reach the outer catch — the disk backup below
+        // is the recovery source.
+        try {
+          if ((await idbGetAllSessions()).length > 0) return;
+        } catch (error) {
+          console.warn(
+            '[AIState] IndexedDB recheck failed during the disk-backup restore;'
+            + ' applying the newest backup generation as the recovery source:',
+            error,
+          );
+        }
+        if (!isMissingOrCorruptSessionsStore(localStorageAdapter.readString(STORAGE_KEY_AI_SESSIONS))) {
+          return;
+        }
         const syncEnabled = !!localStorageAdapter.read<{ enabled?: boolean }>(STORAGE_KEY_CLOUD_SYNC_AI_SESSIONS)?.enabled;
-        const restored = prepareRestoredSessions(recovered, syncEnabled);
+        const restored = prepareRestoredSessions(parseBackupSessions(backup.json) ?? [], syncEnabled);
         if (restored.length === 0) return;
         // Apply restore synchronously (not inside a setState updater). A
         // deferred updater would leave didRestore false and skip dangling
@@ -235,11 +366,7 @@ export function useAIState() {
         setLatestAISessionsSnapshot(restored);
         writeSessionsForStorage(restored);
         emitAIStateChanged(STORAGE_KEY_AI_SESSIONS);
-        // Restore does not change live terminals/workspaces, so the orphan-
-        // cleanup effect will not run. Reuse the last known live target set
-        // (empty is valid: nothing live) so chats bound to missing scopes
-        // become dangling and /chats can offer /rebind.
-        cleanupOrphanedAISessions(latestAIActiveTargetIdsSnapshot);
+        cleanupAfterHydration = true;
         const nextSessions = latestAISessionsSnapshot ?? restored;
         sessionsRef.current = nextSessions;
         setSessionsRaw(nextSessions);
@@ -249,10 +376,25 @@ export function useAIState() {
             ?? {},
         );
         console.info(
-          `[AIState] Restored ${restored.length} AI session(s) from the disk backup.`,
+          `[AIState] Restored ${nextSessions.length} AI session(s) from the disk backup.`,
         );
-      } catch {
-        // Backup restore must never break startup.
+      } catch (error) {
+        // Boot load must never break startup — but it must not vanish
+        // silently either (issue #4125 review P2③).
+        console.warn('[AIState] AI session boot load failed:', error);
+      } finally {
+        markAiSessionsHydrationComplete();
+        if (!cancelled) {
+          // Maintenance may have mounted before hydration with unchanged live
+          // targets. Replay it now against the authoritative boot history.
+          if (cleanupAfterHydration) {
+            cleanupOrphanedAISessions(latestAIActiveTargetIdsSnapshot);
+            const nextSessions = latestAISessionsSnapshot ?? sessionsRef.current;
+            sessionsRef.current = nextSessions;
+            setSessionsRaw(nextSessions);
+          }
+          setSessionsHydrated(true);
+        }
       }
     })();
     return () => {
@@ -321,6 +463,9 @@ export function useAIState() {
 
   useEffect(() => {
     setLatestAIActiveSessionMapSnapshot(activeSessionIdMap);
+    // Issue #4123: mirror the active-pointer map into the IndexedDB meta
+    // store (localStorage stays written at the mutation sites as before).
+    void mirrorActiveSessionMapToIdb(activeSessionIdMap);
   }, [activeSessionIdMap]);
 
   useEffect(() => {
@@ -332,12 +477,12 @@ export function useAIState() {
   }, [panelViewByScope]);
 
   useEffect(() => {
+    // Issue #4125 review P2②: before boot hydration settles, `sessions` is
+    // the initially-empty in-memory array; validating pointers against it
+    // would null every pointer and break workspace restore. No pointer
+    // writes before hydration completes.
+    if (!sessionsHydrated) return;
     const validSessionIds = new Set<string>(sessions.map((session) => session.id));
-    // Disk-only chats may not have arrived from the startup backup read yet.
-    // Keep their active pointers and panel views until recovery or deletion.
-    for (const id of localStorageAdapter.read<string[]>(STORAGE_KEY_AI_SESSIONS_DISK_OVERFLOW) ?? []) {
-      validSessionIds.add(id);
-    }
     let changed = false;
     const nextActiveSessionIdMap: Record<string, string | null> = {};
 
@@ -365,7 +510,7 @@ export function useAIState() {
       emitAIStateChanged(AI_STATE_CHANGED_PANEL_VIEW_BY_SCOPE);
       return next;
     });
-  }, [sessions, activeSessionIdMap]);
+  }, [sessions, activeSessionIdMap, sessionsHydrated]);
 
   const setActiveSessionId = useCallback((scopeKey: string, id: string | null) => {
     let nextActiveSessionIdMap: Record<string, string | null> | null = null;
@@ -557,8 +702,7 @@ export function useAIState() {
   useEffect(() => {
     const handleStorage = (e: StorageEvent) => {
       try {
-        const key = e.key === STORAGE_KEY_AI_SESSIONS_OVERFLOW || e.key?.startsWith(`${STORAGE_KEY_AI_SESSIONS_OVERFLOW}_`)
-          ? STORAGE_KEY_AI_SESSIONS : e.key;
+        const key = e.key;
         switch (key) {
           case STORAGE_KEY_AI_PROVIDERS: {
             const parsed = localStorageAdapter.read<ProviderConfig[]>(STORAGE_KEY_AI_PROVIDERS);
@@ -651,7 +795,10 @@ export function useAIState() {
             break;
           }
           case STORAGE_KEY_AI_SESSIONS: {
-            const nextSessions = readSessionsFromStorage();
+            // Session writes no longer land in localStorage (issue #4123);
+            // the cross-window signal is the IndexedDB change channel and the
+            // storage event only fires as a legacy fallback.
+            const nextSessions = getPersistedAiSessionsSnapshot();
             setLatestAISessionsSnapshot(nextSessions);
             setSessionsRaw(nextSessions);
             break;
@@ -693,7 +840,7 @@ export function useAIState() {
         case STORAGE_KEY_AI_SESSIONS:
           setSessionsRaw(
             latestAISessionsSnapshot
-              ?? readSessionsFromStorage(),
+              ?? getPersistedAiSessionsSnapshot(),
           );
           return;
         case STORAGE_KEY_AI_ACTIVE_SESSION_MAP:
@@ -720,6 +867,37 @@ export function useAIState() {
     };
   }, []);
 
+  // Cross-window AI session sync: session writes land in IndexedDB now, so
+  // the localStorage `storage` event no longer fires for them. Other windows
+  // announce their writes on a BroadcastChannel; the receiver reloads the
+  // store from IndexedDB.
+  useEffect(() => subscribeAiSessionsIdbChange(() => {
+    void (async () => {
+      try {
+        const next = await idbGetAllSessions();
+        if (next.length === 0) {
+          if (!isAiSessionsHydrationComplete()) return;
+          // Issue #4125 review P2④: after hydration an empty store is an
+          // intentional cross-window deletion — adopt it instead of keeping
+          // the deleted session alive locally (its next edit would
+          // resurrect it). The pointer-validation effect clears the
+          // now-stale pointers. Only the pre-hydration window keeps the
+          // early-return: the boot load owns the store view until it
+          // settles.
+          setLatestAISessionsSnapshot([]);
+          seedLastPersistedSessions([]);
+          setSessionsRaw([]);
+          return;
+        }
+        setLatestAISessionsSnapshot(next);
+        seedLastPersistedSessions(next);
+        setSessionsRaw(next);
+      } catch {
+        // Cross-window refresh is best-effort.
+      }
+    })();
+  }), []);
+
   // ── Sync initial safety settings to MCP Server on mount ──
   useEffect(() => {
     const bridge = getAIBridge();
@@ -1031,8 +1209,6 @@ export function useAIState() {
     const syncEnabled = !!localStorageAdapter.read<{ enabled?: boolean }>(STORAGE_KEY_CLOUD_SYNC_AI_SESSIONS)?.enabled;
     const next = prepareRestoredSessions(mergeImportedSessions(sessionsRef.current, imported), syncEnabled);
     if (!writeSessionsForStorage(next)) return 0;
-    // Local readback can omit disk-only overflow chats. Keep the complete
-    // prepared history live so cleanup and later writes retain those chats.
     const importedIds = new Set(imported.map(session => session.id));
     sessionsRef.current = next;
     setLatestAISessionsSnapshot(next);
@@ -1069,22 +1245,27 @@ export function useAIState() {
     });
   }, [debouncedPersistSessions]);
 
-  // Local-only retention. Synced history must match the full-history storage policy.
-  const MAX_MESSAGES_PER_SESSION = 500;
+  // Local-only retention. Synced history must match the full-history storage
+  // policy. The in-memory bound follows the user-configurable per-session cap
+  // (see aiStateSnapshots.readAiSessionMessageCap) but never below this floor,
+  // so the default behavior is unchanged and RAM stays bounded when the user
+  // lowers the persisted cap.
+  const MIN_IN_MEMORY_MESSAGES_PER_SESSION = 500;
 
   const addMessageToSession = useCallback((sessionId: string, message: ChatMessage) => {
     const syncEnabled = localStorageAdapter.read<{ enabled?: boolean }>(STORAGE_KEY_CLOUD_SYNC_AI_SESSIONS)?.enabled === true;
+    const inMemoryCap = Math.max(readAiSessionMessageCap(), MIN_IN_MEMORY_MESSAGES_PER_SESSION);
     setSessionsRaw(prev => {
       const next = prev.map(s => {
         if (s.id !== sessionId) return s;
         let msgs = [...s.messages, message];
         // Dropping synced prefixes makes the next cloud merge add them back.
-        if (!syncEnabled && msgs.length > MAX_MESSAGES_PER_SESSION) {
+        if (!syncEnabled && msgs.length > inMemoryCap) {
           const systemMsgs = msgs.filter(m => m.role === 'system');
           const nonSystemMsgs = msgs.filter(m => m.role !== 'system');
-          const dropped = nonSystemMsgs.length - (MAX_MESSAGES_PER_SESSION - systemMsgs.length);
-          console.warn(`[useAIState] Session ${sessionId}: trimmed ${dropped} oldest non-system message(s) to stay within ${MAX_MESSAGES_PER_SESSION} limit`);
-          msgs = [...systemMsgs, ...nonSystemMsgs.slice(-MAX_MESSAGES_PER_SESSION + systemMsgs.length)];
+          const dropped = nonSystemMsgs.length - (inMemoryCap - systemMsgs.length);
+          console.warn(`[useAIState] Session ${sessionId}: trimmed ${dropped} oldest non-system message(s) to stay within ${inMemoryCap} limit`);
+          msgs = [...systemMsgs, ...nonSystemMsgs.slice(-inMemoryCap + systemMsgs.length)];
         }
         return { ...s, messages: msgs, updatedAt: Date.now() };
       });
@@ -1322,10 +1503,11 @@ export function useAIState() {
 
   const cleanupOrphanedSessions = useCallback((activeTargetIds: Set<string>) => {
     cleanupOrphanedAISessions(activeTargetIds);
+    if (!isAiSessionsHydrationComplete()) return;
 
     const nextSessions =
       latestAISessionsSnapshot
-      ?? readSessionsFromStorage();
+      ?? getPersistedAiSessionsSnapshot();
     sessionsRef.current = nextSessions;
     setSessionsRaw(nextSessions);
     setActiveSessionIdMapRaw(
@@ -1377,7 +1559,7 @@ export function useAIState() {
       ?? {};
     const currentSessions =
       latestAISessionsSnapshot
-      ?? readSessionsFromStorage();
+      ?? getPersistedAiSessionsSnapshot();
     const currentPanelViewByScope = latestAIPanelViewByScopeSnapshot ?? {};
     const result = handoffDissolvedWorkspaceAIScope({
       activeSessionIdMap: currentMap,
@@ -1415,6 +1597,7 @@ export function useAIState() {
     previousMemberTerminalIds: readonly string[];
     currentMemberTerminalIds: readonly string[];
     preferredTerminalId?: string | null;
+    activeTargetIds?: ReadonlySet<string>;
   }) => {
     const currentMap =
       latestAIActiveSessionMapSnapshot
@@ -1422,7 +1605,7 @@ export function useAIState() {
       ?? {};
     const currentSessions =
       latestAISessionsSnapshot
-      ?? readSessionsFromStorage();
+      ?? getPersistedAiSessionsSnapshot();
     const result = retargetWorkspaceActiveChatAfterMemberLoss({
       activeSessionIdMap: currentMap,
       sessions: currentSessions,
@@ -1430,6 +1613,7 @@ export function useAIState() {
       previousMemberTerminalIds: input.previousMemberTerminalIds,
       currentMemberTerminalIds: input.currentMemberTerminalIds,
       preferredTerminalId: input.preferredTerminalId,
+      activeTargetIds: input.activeTargetIds,
     });
     if (!result.changed) return;
 

application/state/useAIState.undoLastTurn.test.ts

@@ -9,7 +9,7 @@ import { getAgentRuntime } from '../../infrastructure/ai/harness/globalAgentRunt
 import { useAIState } from './useAIState.ts';
 import { useAISessionsStore } from './aiSessionsStore.ts';
 import { getSessionScopeMatchRank } from '../../components/ai/sessionScopeMatch.ts';
-import { setLatestAISessionsSnapshot } from './aiStateSnapshots.ts';
+import { getPersistedAiSessionsSnapshot, setLatestAISessionsSnapshot } from './aiStateSnapshots.ts';
 
 const SCOPE_KEY = 'terminal:terminal-a';
 
@@ -175,17 +175,21 @@ for (const newerCount of [49, 50]) {
       branchId = (await capture.ai!.undoLastTurnInSession(SOURCE_SESSION.id))?.sessionId;
     });
     assert.ok(branchId);
-    const saved: AISession[] = JSON.parse(dom.window.localStorage.getItem('netcatty_ai_sessions_v1')!);
-    assert.equal(saved.length, 50);
+    // Issue #4123: the persisted set lives in IndexedDB (count cap 1000, so
+    // nothing is evicted at these sizes) — not in a 50-capped localStorage blob.
+    const saved: AISession[] = getPersistedAiSessionsSnapshot();
+    assert.equal(saved.length, newerCount + 2);
     const original = saved.find(item => item.id === SOURCE_SESSION.id);
     assert.ok(original, 'the original must survive updatedAt-based history pruning');
     assert.deepEqual({ ...original, updatedAt: SOURCE_SESSION.updatedAt }, SOURCE_SESSION);
     assert.deepEqual(saved.find(item => item.id === branchId)?.messages, SOURCE_SESSION.messages.slice(0, 2));
     assert.ok(original.updatedAt >= newer.at(-1)!.updatedAt);
     await act(async () => root.unmount());
-    container.remove(); dom.window.close();
-
-    // Remount the actual hook from the persisted records, as on app reload.
+    container.remove();
+    // Seed the read-only legacy store with the persisted set (the stand-in
+    // for what the migration persists on a profile without IndexedDB).
+    dom.window.localStorage.setItem('netcatty_ai_sessions_v1', JSON.stringify(saved));
+    dom.window.close();
     const reloaded = await setupAiState(saved);
     assert.deepEqual(reloaded.capture.sessions.find(item => item.id === SOURCE_SESSION.id)?.messages, SOURCE_SESSION.messages);
     assert.deepEqual(reloaded.capture.sessions.find(item => item.id === branchId)?.messages, SOURCE_SESSION.messages.slice(0, 2));
@@ -223,7 +227,7 @@ for (const viewingScope of [
     ), 3);
     const original = capture.sessions.find(item => item.id === source.id)!;
     assert.deepEqual({ ...original, updatedAt: sourceBefore.updatedAt }, sourceBefore);
-    const saved = JSON.parse(dom.window.localStorage.getItem('netcatty_ai_sessions_v1')!) as AISession[];
+    const saved = getPersistedAiSessionsSnapshot();
     assert.deepEqual(saved.find(item => item.id === branchId)?.scope, branch.scope);
     await act(async () => root.unmount());
     container.remove(); dom.window.close();

application/state/useActiveChromeTheme.test.ts

@@ -156,6 +156,139 @@ for (const preference of ["system", "light", "dark"] as const) {
   }
 }
 
+// A hanging jsdom/React render must fail this test quickly instead of
+// consuming the whole CI job budget.
+test("terminal chrome never replaces the application native theme policy", { timeout: 15000 }, async () => {
+  const { JSDOM } = await import("jsdom");
+  const dom = new JSDOM('<!doctype html><html><head></head><body><div data-top-tabs-root></div></body></html>');
+  const originalWindow = globalThis.window;
+  const originalDocument = globalThis.document;
+  const originalSnapshot = getSettingsChromeSnapshot();
+  const themeSources: string[] = [];
+  const backgrounds: string[] = [];
+  const testWindow = dom.window as unknown as Window & typeof globalThis;
+  testWindow.netcatty = {
+    setTheme: async (source: string) => { themeSources.push(source); return true; },
+    setBackgroundColor: async (background: string) => { backgrounds.push(background); return true; },
+  } as unknown as NetcattyBridge;
+  globalThis.window = testWindow;
+  globalThis.document = testWindow.document;
+  try {
+    publishSettingsChromeSnapshot({ ...originalSnapshot, theme: "system" });
+    for (const type of ['light', 'dark'] as const) {
+      const theme = TERMINAL_THEMES.find((candidate) => candidate.type === type);
+      assert.ok(theme);
+      syncActiveChromeTheme(theme, () => {});
+      assert.equal(document.documentElement.classList.contains(type), true);
+      assert.equal(backgrounds.at(-1), theme.colors.background);
+    }
+    assert.deepEqual(themeSources, ['system', 'system'], 'terminal colors must not pin nativeTheme.themeSource to light/dark');
+  } finally {
+    publishSettingsChromeSnapshot(originalSnapshot);
+    globalThis.window = originalWindow;
+    globalThis.document = originalDocument;
+    dom.window.close();
+  }
+});
+
+test("system preference refresh reapplies an unchanged independent terminal chrome", { timeout: 15000 }, async () => {
+  const { JSDOM } = await import("jsdom");
+  const dom = new JSDOM('<!doctype html><html><head></head><body><div data-top-tabs-root></div></body></html>');
+  const originalWindow = globalThis.window;
+  const originalDocument = globalThis.document;
+  const originalSnapshot = getSettingsChromeSnapshot();
+  const backgrounds: string[] = [];
+  const testWindow = dom.window as unknown as Window & typeof globalThis;
+  testWindow.netcatty = {
+    setTheme: (source: string) => {
+      assert.equal(source, 'system', 'chrome refresh must preserve native system theme policy');
+      return Promise.resolve(true);
+    },
+    setBackgroundColor: async (background: string) => { backgrounds.push(background); return true; },
+  } as unknown as NetcattyBridge;
+  globalThis.window = testWindow;
+  globalThis.document = testWindow.document;
+  try {
+    publishSettingsChromeSnapshot({ ...originalSnapshot, theme: "system" });
+    for (const type of ['light', 'dark'] as const) {
+      const theme = TERMINAL_THEMES.find((candidate) => candidate.type === type);
+      assert.ok(theme);
+      syncActiveChromeTheme(theme, () => {});
+      // The application settings effect runs first on an OS preference change.
+      document.documentElement.className = type === 'dark' ? 'light' : 'dark';
+      backgrounds.push('application-background');
+      syncActiveChromeTheme(theme, () => {}, { refreshSurfaces: true });
+      assert.equal(document.documentElement.classList.contains(type), true);
+      assert.equal(backgrounds.at(-1), theme.colors.background);
+    }
+    syncActiveChromeTheme(null, () => {
+      document.documentElement.className = 'light';
+      backgrounds.push('application-background');
+    });
+    assert.equal(document.documentElement.className, 'light');
+    assert.equal(document.documentElement.dataset.activeChromeTheme, undefined);
+    assert.equal(document.getElementById('netcatty-active-chrome-theme'), null);
+    assert.equal(backgrounds.at(-1), 'application-background');
+  } finally {
+    publishSettingsChromeSnapshot(originalSnapshot);
+    globalThis.window = originalWindow;
+    globalThis.document = originalDocument;
+    dom.window.close();
+  }
+});
+
+test("chrome hook reacts to OS preference changes with stable terminal props", { timeout: 15000 }, async () => {
+  const { JSDOM } = await import('jsdom');
+  const { act, createElement } = await import('react');
+  const { createRoot } = await import('react-dom/client');
+  const { useActiveChromeTheme } = await import('./useActiveChromeTheme');
+  const { getSettingsChromeSnapshot, publishSettingsChromeSnapshot } = await import('./settingsChromeStore');
+  const dom = new JSDOM('<!doctype html><html><head></head><body></body></html>');
+  const originalWindow = globalThis.window;
+  const originalDocument = globalThis.document;
+  const originalSnapshot = getSettingsChromeSnapshot();
+  const environment = globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean };
+  const originalActEnvironment = environment.IS_REACT_ACT_ENVIRONMENT;
+  environment.IS_REACT_ACT_ENVIRONMENT = true;
+  const backgrounds: string[] = [];
+  const testWindow = dom.window as unknown as Window & typeof globalThis;
+  globalThis.window = testWindow;
+  globalThis.document = dom.window.document;
+  testWindow.netcatty = {
+    setBackgroundColor: async (color: string) => { backgrounds.push(color); return true; },
+  } as unknown as NetcattyBridge;
+  const theme = TERMINAL_THEMES.find((candidate) => candidate.type === 'dark');
+  assert.ok(theme);
+  const applyAppTheme = () => {};
+  function Harness() {
+    useActiveChromeTheme({ activeTheme: theme!, applyAppTheme });
+    return null;
+  }
+  publishSettingsChromeSnapshot({ ...originalSnapshot, resolvedTheme: 'dark' });
+  let renderer: ReturnType<typeof createRoot> | undefined;
+  try {
+    await act(async () => {
+      renderer = createRoot(document.createElement('div'));
+      renderer.render(createElement(Harness));
+    });
+    assert.equal(document.documentElement.classList.contains('dark'), true);
+    document.documentElement.className = 'light';
+    backgrounds.push('application-background');
+    await act(async () => {
+      publishSettingsChromeSnapshot({ ...originalSnapshot, resolvedTheme: 'light' });
+    });
+    assert.equal(document.documentElement.classList.contains('dark'), true);
+    assert.equal(backgrounds.at(-1), theme.colors.background);
+  } finally {
+    await act(async () => { renderer?.unmount(); });
+    environment.IS_REACT_ACT_ENVIRONMENT = originalActEnvironment;
+    publishSettingsChromeSnapshot(originalSnapshot);
+    globalThis.window = originalWindow;
+    globalThis.document = originalDocument;
+    dom.window.close();
+  }
+});
+
 test("active chrome theme foreground uses contrast calculation", () => {
   const source = readFileSync(new URL("./useActiveChromeTheme.ts", import.meta.url), "utf8");
 

application/state/useActiveChromeTheme.ts

@@ -237,9 +237,9 @@ function applyActiveChromeTheme(theme: TerminalTheme) {
 }
 
 function refreshActiveChromeThemeSurfaces(theme: TerminalTheme) {
-  const targetClass = theme.type === "dark" ? "dark" : "light";
   if (typeof window !== "undefined") {
     // Preserve OS preference events instead of locking nativeTheme to the chrome type.
+    const targetClass = theme.type === "dark" ? "dark" : "light";
     const themeSource = getSettingsChromeSnapshot().theme === "system" ? "system" : targetClass;
     netcattyBridge.get()?.setTheme?.(themeSource);
     netcattyBridge.get()?.setBackgroundColor?.(theme.colors.background);
@@ -250,10 +250,11 @@ function refreshActiveChromeThemeSurfaces(theme: TerminalTheme) {
 export function syncActiveChromeTheme(
   activeTheme: TerminalTheme | null,
   applyAppTheme: () => void,
+  { refreshSurfaces = false }: { refreshSurfaces?: boolean } = {},
 ): void {
   const nextFingerprint = activeTheme ? themeFingerprint(activeTheme) : null;
   const appliedFingerprint = getAppliedChromeFingerprint();
-  if (nextFingerprint === appliedFingerprint) {
+  if (nextFingerprint === appliedFingerprint && !(activeTheme && refreshSurfaces)) {
     return;
   }
 
@@ -283,8 +284,11 @@ export function useActiveChromeTheme({
   applyAppThemeRef.current = applyAppTheme;
 
   useLayoutEffect(() => {
-    syncActiveChromeTheme(effectiveTheme, applyAppTheme);
-  }, [effectiveTheme, applyAppTheme, pluginThemeRevision]);
+    // Settings may have just applied the OS theme over a fixed terminal theme.
+    // Reassert its visual surfaces even when the terminal fingerprint is stable;
+    // tab-switch callers retain the default fingerprint fast path.
+    syncActiveChromeTheme(effectiveTheme, applyAppTheme, { refreshSurfaces: true });
+  }, [effectiveTheme, applyAppTheme, pluginThemeRevision, resolvedTheme]);
 
   useLayoutEffect(() => {
     return () => {

application/state/useComposeBarHeight.ts

@@ -2,8 +2,8 @@ import { useCallback } from 'react';
 import { STORAGE_KEY_COMPOSE_BAR_HEIGHT } from '../../infrastructure/config/storageKeys';
 import { useStoredNumber } from './useStoredNumber';
 
-export const COMPOSE_BAR_HEIGHT_DEFAULT = 120;
-export const COMPOSE_BAR_HEIGHT_MIN = 72;
+export const COMPOSE_BAR_HEIGHT_DEFAULT = 144;
+export const COMPOSE_BAR_HEIGHT_MIN = 104;
 export const COMPOSE_BAR_HEIGHT_MAX = 360;
 
 const HEIGHT_CLAMP = { min: COMPOSE_BAR_HEIGHT_MIN, max: COMPOSE_BAR_HEIGHT_MAX };

application/state/useComposeDirectoryPicker.test.ts

@@ -0,0 +1,106 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import React from 'react';
+import { act, create, type ReactTestRenderer } from 'react-test-renderer';
+import { useComposeDirectoryPicker } from './useComposeDirectoryPicker';
+import { createTerminalDirectoryController } from './terminalDirectoryController';
+import { refreshObservedTerminalDirectory, registerTerminalDirectory } from './terminalDirectoryRegistry';
+import { terminalCwdStore } from './terminalCwdStore';
+import { DirectoryPickerError } from '../../domain/directoryPicker';
+
+Object.assign(globalThis, { IS_REACT_ACT_ENVIRONMENT: true });
+
+test('opening loads children once; search is local; unmount stops chip refresh demand', async () => {
+  let reads = 0; let probes = 0;
+  const id = 'hook-directory';
+  const controller = createTerminalDirectoryController({ sessionId: id,
+    io: { cwd: async () => { probes++; return '/base'; }, realpath: async path => path, write() {},
+      list: async () => { reads++; return { home: '/base', entries: [{ name: 'child', path: '/base/child', hidden: false }] }; } },
+    isCurrent: () => true, isReady: () => true,
+    publish: cwd => { terminalCwdStore.setCwd(id, cwd, 'backend-strict'); },
+  });
+  const cleanup = registerTerminalDirectory(id, controller);
+  let model!: ReturnType<typeof useComposeDirectoryPicker>;
+  function Harness() { model = useComposeDirectoryPicker(id); return null; }
+  let root!: ReactTestRenderer;
+  await act(async () => { root = create(React.createElement(Harness)); });
+  assert.equal(model.cwd, '/base');
+  await act(async () => { model.setOpen(true); });
+  assert.equal(reads, 1);
+  await act(async () => { model.setQuery('CH'); });
+  assert.equal(model.entries.length, 1);
+  assert.equal(reads, 1);
+  await act(async () => { root.unmount(); });
+  const before = probes;
+  refreshObservedTerminalDirectory(id);
+  await Promise.resolve();
+  assert.equal(probes, before);
+  cleanup();
+});
+
+test('switching terminal cancels an old directory read and closes its popover', async () => {
+  let finish!: (value: { entries: { name: string; path: string; hidden: boolean }[]; home: null }) => void;
+  const cleanups = ['hook-a', 'hook-b'].map(id => registerTerminalDirectory(id, createTerminalDirectoryController({
+    sessionId: id, isCurrent: () => true, isReady: () => true,
+    io: { cwd: async () => '/' + id, realpath: async path => path, write() {},
+      list: () => new Promise(resolve => { finish = resolve; }) },
+    publish: cwd => { terminalCwdStore.setCwd(id, cwd, 'backend-strict'); },
+  })));
+  let model!: ReturnType<typeof useComposeDirectoryPicker>;
+  function Harness({ id }: { id: string }) { model = useComposeDirectoryPicker(id); return null; }
+  let root!: ReactTestRenderer;
+  await act(async () => { root = create(React.createElement(Harness, { id: 'hook-a' })); });
+  await act(async () => { model.setOpen(true); });
+  await act(async () => { root.update(React.createElement(Harness, { id: 'hook-b' })); });
+  await act(async () => { finish({ entries: [{ name: 'old', path: '/hook-a/old', hidden: false }], home: null }); });
+  assert.equal(model.open, false);
+  assert.equal(model.cwd, '/hook-b');
+  assert.deepEqual(model.entries, []);
+  await act(async () => { root.unmount(); });
+  cleanups.forEach(cleanup => cleanup());
+});
+
+test('reconnect after an aborted listing allows manual recovery from a failed cwd probe', async t => {
+  const id = 'hook-directory-reconnect';
+  let finishOld!: (value: { entries: { name: string; path: string; hidden: boolean }[]; home: null }) => void;
+  const oldController = createTerminalDirectoryController({
+    sessionId: id, isCurrent: () => true, isReady: () => true,
+    io: { cwd: async () => '/old', realpath: async value => value, write() {},
+      list: () => new Promise(resolve => { finishOld = resolve; }) },
+    publish: cwd => { terminalCwdStore.setCwd(id, cwd, 'backend-strict'); },
+  });
+  const unregisterOld = registerTerminalDirectory(id, oldController);
+  let model!: ReturnType<typeof useComposeDirectoryPicker>;
+  function Harness() { model = useComposeDirectoryPicker(id); return null; }
+  let root!: ReactTestRenderer;
+  let unregisterNew = () => {};
+  t.after(async () => {
+    await act(async () => { root.unmount(); });
+    unregisterOld(); unregisterNew();
+  });
+  await act(async () => { root = create(React.createElement(Harness)); });
+  await act(async () => { model.setOpen(true); });
+  assert.equal(model.loading, true);
+  // Close while the request is pending, so the read is already aborted when
+  // the disconnect disposes its controller and settles the old promise.
+  await act(async () => { model.setOpen(false); });
+  await act(async () => { unregisterOld(); terminalCwdStore.setCwd(id, null); });
+  let failProbe = true;
+  const nextController = createTerminalDirectoryController({
+    sessionId: id, isCurrent: () => true, isReady: () => true,
+    io: { cwd: async () => { if (failProbe) throw new DirectoryPickerError('unknown'); return '/recovered'; },
+      realpath: async value => value, write() {},
+      list: async () => ({ entries: [{ name: 'new', path: '/recovered/new', hidden: false }], home: null }) },
+    publish: cwd => { terminalCwdStore.setCwd(id, cwd, 'backend-strict'); },
+  });
+  await act(async () => { unregisterNew = registerTerminalDirectory(id, nextController); });
+  assert.equal(model.cwd, null);
+  assert.equal(model.error, 'unknown');
+  assert.equal(model.loading, false, 'cancelled reads must not leave the manual Refresh action disabled');
+  await act(async () => { failProbe = false; await model.refresh(); model.setOpen(true); });
+  assert.equal(model.cwd, '/recovered');
+  assert.equal(model.loading, false);
+  assert.deepEqual(model.entries.map(entry => entry.name), ['new']);
+  await act(async () => { finishOld({ entries: [{ name: 'stale', path: '/old/stale', hidden: false }], home: null }); });
+  assert.deepEqual(model.entries.map(entry => entry.name), ['new']);
+});

application/state/useComposeDirectoryPicker.ts

@@ -0,0 +1,94 @@
+import { useCallback, useEffect, useMemo, useRef, useState, useSyncExternalStore } from 'react';
+import { DirectoryPickerError, directoryParent, filterDirectories, type DirectoryEntry, type DirectoryPickerErrorCode } from '../../domain/directoryPicker';
+import { terminalCwdStore } from './terminalCwdStore';
+import { getTerminalDirectory, observeTerminalDirectory, subscribeTerminalDirectories } from './terminalDirectoryRegistry';
+
+export function useComposeDirectoryPicker(sessionId: string) {
+  const controller = useSyncExternalStore(subscribeTerminalDirectories, () => getTerminalDirectory(sessionId), () => null);
+  useSyncExternalStore(terminalCwdStore.subscribe, terminalCwdStore.getVersion, terminalCwdStore.getVersion);
+  const [confirmed, setConfirmed] = useState(false);
+  const cwd = controller && (confirmed || controller.hasConfirmedCwd() || terminalCwdStore.getSource(sessionId) === 'osc7')
+    ? terminalCwdStore.getCwd(sessionId) : null;
+  const [open, setOpen] = useState(false);
+  const [query, setQuery] = useState('');
+  const [showHidden, setShowHidden] = useState(false);
+  const [entries, setEntries] = useState<DirectoryEntry[]>([]);
+  const [home, setHome] = useState<string | null>(null);
+  const [loading, setLoading] = useState(false);
+  const [pending, setPending] = useState(false);
+  const listingBase = useRef<string | null>(null);
+  const [error, setError] = useState<DirectoryPickerErrorCode | null>(null);
+  const generation = useRef(0);
+  const lifetime = useRef(new AbortController());
+  const read = useRef<AbortController | null>(null);
+  const sending = useRef(false);
+  const report = useCallback((failure: unknown, fallback: DirectoryPickerErrorCode) => {
+    setError(failure instanceof DirectoryPickerError ? failure.code : fallback);
+  }, []);
+
+  useEffect(() => {
+    const id = ++generation.current;
+    const stopObserving = observeTerminalDirectory(sessionId);
+    lifetime.current = new AbortController();
+    sending.current = false;
+    setConfirmed(false); setOpen(false); setPending(false); setLoading(false); setHome(null); setError(null); setEntries([]);
+    listingBase.current = null;
+    if (controller) void Promise.all([controller.refresh(), controller.home()]).then(([, nextHome]) => {
+      if (generation.current === id) { setConfirmed(true); setHome(nextHome); }
+    }).catch(failure => { if (generation.current === id) report(failure, 'unknown'); });
+    return () => {
+      generation.current = id + 1;
+      lifetime.current.abort(); read.current?.abort(); stopObserving();
+    };
+  }, [sessionId, controller, report]);
+
+  const refresh = useCallback(async () => {
+    if (!controller) { setError('unavailable'); return; }
+    const id = generation.current;
+    setError(null);
+    try { await controller.refresh(); if (generation.current === id) setConfirmed(true); }
+    catch (failure) { if (generation.current === id) report(failure, 'unknown'); }
+  }, [controller, report]);
+
+  const load = useCallback(async () => {
+    if (!controller || !cwd) return;
+    read.current?.abort();
+    const task = new AbortController(); read.current = task;
+    const id = generation.current;
+    setLoading(true); setEntries([]); setError(null);
+    try {
+      const result = await controller.list(cwd, task.signal);
+      if (!task.signal.aborted && id === generation.current) {
+        listingBase.current = cwd; setEntries(result.entries); setHome(result.home);
+      }
+    } catch (failure) {
+      if (!task.signal.aborted && id === generation.current) report(failure, 'readFailed');
+    } finally { if (!task.signal.aborted && id === generation.current) setLoading(false); }
+  }, [controller, cwd, report]);
+
+  useEffect(() => {
+    if (open) { setQuery(''); void load(); }
+    return () => { read.current?.abort(); };
+  }, [open, load]);
+
+  const change = useCallback(async (path: string) => {
+    if (!controller) { setError('unavailable'); return; }
+    if (sending.current) return;
+    if (!cwd || terminalCwdStore.getCwd(sessionId) !== cwd
+      || (path !== directoryParent(cwd) && listingBase.current !== cwd)) { setError('unavailable'); return; }
+    sending.current = true; setPending(true); setError(null);
+    const id = generation.current;
+    try {
+      await controller.change(path, lifetime.current.signal, () => {
+        if (id === generation.current) setOpen(false);
+      }, cwd ?? undefined);
+    } catch (failure) { if (id === generation.current) report(failure, 'changeFailed'); }
+    finally {
+      if (id === generation.current) { sending.current = false; setPending(false); }
+    }
+  }, [controller, report, cwd, sessionId]);
+
+  const filtered = useMemo(() => filterDirectories(entries, query, showHidden), [entries, query, showHidden]);
+  return { cwd, home, open, setOpen, query, setQuery, showHidden, setShowHidden, entries: filtered,
+    parent: cwd ? directoryParent(cwd) : null, loading, pending, error, available: !!controller, refresh, reload: load, change };
+}

application/state/usePluginGitHubInstall.ts

@@ -0,0 +1,59 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+import { netcattyBridge } from '../../infrastructure/services/netcattyBridge';
+import { parsePluginGitHubRepository } from '@/domain/pluginGitHubRepository.cjs';
+
+export function usePluginGitHubInstall(onInstalled: () => Promise<unknown>) {
+  const [preview, setPreview] = useState<NetcattyGitHubPluginPreview | null>(null);
+  const [busy, setBusy] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const token = useRef<string | null>(null);
+  const active = useRef(false);
+  const mounted = useRef(true);
+  const reset = useCallback(() => {
+    const previous = token.current;
+    token.current = null;
+    setPreview(null);
+    setError(null);
+    if (previous) void netcattyBridge.get()?.discardGitHubPlugin?.(previous).catch(() => {});
+  }, []);
+  useEffect(() => {
+    mounted.current = true;
+    return () => {
+      mounted.current = false;
+      if (token.current) void netcattyBridge.get()?.discardGitHubPlugin?.(token.current).catch(() => {});
+    };
+  }, []);
+  const run = async (operation: () => Promise<void>) => {
+    if (active.current) return;
+    active.current = true;
+    setBusy(true);
+    setError(null);
+    try { await operation(); }
+    catch (cause) { if (mounted.current) setError(cause instanceof Error ? cause.message : String(cause)); }
+    finally { active.current = false; if (mounted.current) setBusy(false); }
+  };
+  return {
+    preview, busy, error, reset,
+    prepare: (input: string) => run(async () => {
+      const { origin } = parsePluginGitHubRepository(input);
+      const bridge = netcattyBridge.require();
+      if (!bridge.prepareGitHubPlugin) throw new Error('GitHub plugin installation unavailable');
+      reset();
+      const result = await bridge.prepareGitHubPlugin(origin);
+      if (!mounted.current) { await bridge.discardGitHubPlugin?.(result.token); return; }
+      token.current = result.token;
+      setPreview(result);
+    }),
+    install: () => run(async () => {
+      const bridge = netcattyBridge.require();
+      if (!bridge.installGitHubPlugin || !token.current) throw new Error('Download and review a GitHub plugin first');
+      const selected = token.current;
+      // The host consumes the selection even on failure; retry starts with a new review.
+      token.current = null;
+      setPreview(null);
+      await bridge.installGitHubPlugin(selected);
+      await onInstalled();
+      window.dispatchEvent(new Event('netcatty:plugin-packages-changed'));
+    }),
+  };
+}

application/state/useSessionState.composeBroadcast.test.ts

@@ -4,6 +4,9 @@ import React from "react";
 import { act, create, type ReactTestRenderer } from "react-test-renderer";
 
 import { useSessionState } from "./useSessionState.ts";
+import { installTestLocalStorage } from "./testSupport/localStorage.ts";
+
+test.beforeEach((t) => { t.after(installTestLocalStorage()); });
 
 type SessionState = ReturnType<typeof useSessionState>;
 

application/state/useSessionState.globalBroadcast.test.ts

@@ -4,6 +4,9 @@ import React from "react";
 import { act, create, type ReactTestRenderer } from "react-test-renderer";
 
 import { useSessionState } from "./useSessionState.ts";
+import { installTestLocalStorage } from "./testSupport/localStorage.ts";
+
+test.beforeEach((t) => { t.after(installTestLocalStorage()); });
 
 type SessionState = ReturnType<typeof useSessionState>;
 
@@ -86,6 +89,15 @@ test("global broadcast availability follows visible orphan session count", async
     await act(async () => {
       current().removeSessionFromWorkspace(second.id);
     });
+    // The one-member workspace stays intact; only the detached terminal is
+    // an orphan, so global broadcast remains unavailable until another opens.
+    assert.equal(current().workspaces.length, 1);
+    assert.equal(current().sessions.find(session => session.id === first.id)?.workspaceId, current().workspaces[0].id);
+    assert.deepEqual(current().orphanSessions.map(session => session.id), [second.id]);
+    assert.equal(current().canUseGlobalBroadcast, false);
+    assert.equal(current().isGlobalBroadcastEnabled, false);
+    await act(async () => { current().createLocalTerminal({ shellName: "04" }); });
+    assert.equal(current().orphanSessions.length, 2);
     assert.equal(current().canUseGlobalBroadcast, true);
     assert.equal(current().isGlobalBroadcastEnabled, false);
   } finally {

application/state/useSessionState.moveWorkspacePane.test.ts

@@ -0,0 +1,92 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import type { Workspace } from '../../domain/models';
+import { collectSessionIds } from '../../domain/workspace';
+import { moveWorkspacePaneInWorkspaces } from './useSessionState';
+
+// Issue #4037: moving a member pane must rearrange only the tree shape.
+// Session ids, workspace id, anchorChatId (AI binding), focus fields and tab
+// order all live outside the touched surface, and these tests pin that.
+
+const workspace = (id = 'ws-1'): Workspace => ({
+  id,
+  title: 'Workspace',
+  focusedSessionId: 's1',
+  focusSessionOrder: ['s1', 's2', 's3'],
+  anchorChatId: 'chat-anchor-1',
+  root: {
+    id: 'split-1',
+    type: 'split',
+    direction: 'vertical',
+    children: [
+      { id: 'pane-1', type: 'pane', sessionId: 's1' },
+      { id: 'pane-2', type: 'pane', sessionId: 's2' },
+      { id: 'pane-3', type: 'pane', sessionId: 's3' },
+    ],
+    sizes: [1, 1, 1],
+  },
+});
+
+test('moveWorkspacePaneInWorkspaces rearranges the tree and preserves every identity field', () => {
+  const ws = workspace();
+  const next = moveWorkspacePaneInWorkspaces([ws], 'ws-1', 's3', {
+    direction: 'vertical',
+    position: 'left',
+    targetSessionId: 's1',
+  });
+
+  assert.equal(next.length, 1);
+  const moved = next[0];
+  assert.equal(moved.id, ws.id, 'workspace id (AI binding key) unchanged');
+  assert.equal(moved.title, ws.title);
+  assert.equal(moved.anchorChatId, 'chat-anchor-1', 'anchorChatId unchanged');
+  assert.equal(moved.focusedSessionId, 's1', 'focus stays on the same session id');
+  assert.deepEqual(moved.focusSessionOrder, ['s1', 's2', 's3'], 'tab/focus order unchanged');
+  assert.deepEqual(collectSessionIds(moved.root), ['s3', 's1', 's2']);
+  assert.notEqual(moved.root, ws.root, 'the tree shape actually changed');
+});
+
+test('moveWorkspacePaneInWorkspaces leaves other workspaces and no-op cases untouched', () => {
+  const ws1 = workspace('ws-1');
+  const ws2 = workspace('ws-2');
+
+  // Same-reference no-op: pane dropped onto itself.
+  const selfDrop = moveWorkspacePaneInWorkspaces([ws1, ws2], 'ws-1', 's2', {
+    direction: 'vertical',
+    position: 'left',
+    targetSessionId: 's2',
+  });
+  assert.equal(selfDrop[0], ws1, 'no-op workspace keeps its reference');
+  assert.equal(selfDrop[1], ws2);
+
+  // Unknown session / foreign workspace id: nothing moves.
+  const ghost = moveWorkspacePaneInWorkspaces([ws1, ws2], 'ws-1', 'ghost', {
+    direction: 'vertical',
+    position: 'left',
+    targetSessionId: 's1',
+  });
+  assert.equal(ghost[0], ws1);
+  assert.equal(ghost[1], ws2);
+
+  const foreign = moveWorkspacePaneInWorkspaces([ws1, ws2], 'ws-other', 's1', {
+    direction: 'vertical',
+    position: 'left',
+    targetSessionId: 's2',
+  });
+  assert.equal(foreign[0], ws1);
+  assert.equal(foreign[1], ws2);
+});
+
+test('moveWorkspacePaneInWorkspaces only rewrites the targeted workspace entry', () => {
+  const ws1 = workspace('ws-1');
+  const ws2 = workspace('ws-2');
+  const next = moveWorkspacePaneInWorkspaces([ws1, ws2], 'ws-2', 's2', {
+    direction: 'vertical',
+    position: 'right',
+    targetSessionId: 's3',
+  });
+  assert.equal(next[0], ws1, 'sibling workspaces keep their references');
+  assert.notEqual(next[1], ws2);
+  assert.deepEqual(collectSessionIds(next[1].root), ['s1', 's3', 's2']);
+});

application/state/useSessionState.ts

@@ -19,6 +19,7 @@ createWorkspaceFromSessionIds,
 FocusDirection,
 getNextFocusSessionId,
 insertPaneIntoWorkspace,
+movePaneInWorkspace,
 pruneWorkspaceNode,
 reorderWorkspaceFocusSessionOrder,
 setWorkspaceFocusedSessionId,
@@ -42,8 +43,9 @@ import {
 import {
   closeSessionsState,
   detachSessionFromWorkspaceState,
-  replaceDissolvedWorkspaceTabOrder,
 } from './sessionWorkspaceDetach';
+import { getAISessionsSnapshot } from './aiSessionsStore';
+import { getPersistedAiSessionsSnapshot } from './aiStateSnapshots';
 import {
   createCopiedTerminalSessionClone,
   createSplitTerminalSessionClone,
@@ -122,6 +124,26 @@ export function appendWorkspaceRootPaneIfMissing(
   });
 }
 
+/**
+ * Issue #4037: rearrange an existing member pane within its own workspace.
+ * Only `workspaces[].root` shape changes — session ids, tab order, focus
+ * fields and every AI binding (anchorChatId / activeSessionIdMap scopes) are
+ * untouched, because the moved session keeps its id and its workspaceId.
+ */
+export function moveWorkspacePaneInWorkspaces(
+  workspaces: Workspace[],
+  workspaceId: string,
+  sessionId: string,
+  hint: SplitHint,
+): Workspace[] {
+  return workspaces.map(ws => {
+    if (ws.id !== workspaceId) return ws;
+    if (!collectSessionIds(ws.root).includes(sessionId)) return ws;
+    const nextRoot = movePaneInWorkspace(ws.root, sessionId, hint);
+    return nextRoot === ws.root ? ws : { ...ws, root: nextRoot };
+  });
+}
+
 export function insertCopiedTabOrderIdOnce(
   prevTabOrder: string[],
   sourceTabId: string,
@@ -615,6 +637,11 @@ export const useSessionState = ({
       currentActiveTabId: activeTabStore.getActiveTabId(),
       preferredTabId: activeTabStore.getPreviousActiveTabId(),
       tabOrder: tabOrderRef.current,
+      // AI chat recency decides which surviving member receives focus/anchor
+      // after member loss (#4098 phase 2); hot store first, persisted fallback.
+      aiSessions: getAISessionsSnapshot().sessions.length > 0
+        ? getAISessionsSnapshot().sessions
+        : getPersistedAiSessionsSnapshot(),
     });
 
     setWorkspaces(result.workspaces);
@@ -822,6 +849,20 @@ export const useSessionState = ({
 	    });
 	  }, [setActiveTabId]);
 
+  // Issue #4037: drop an existing member pane back into its own workspace to
+  // rearrange it. Deliberately touches nothing but the pane tree: no session
+  // fields, no tab order, no focus changes (focusedSessionId keeps pointing
+  // at the same session id, so focus visually follows the moved pane), and
+  // no AI state — the anchorChatId lives on the workspace, which keeps its id.
+  const moveWorkspacePane = useCallback((
+    workspaceId: string,
+    sessionId: string,
+    hint: SplitHint
+  ) => {
+    if (!hint) return;
+    setWorkspaces(prev => moveWorkspacePaneInWorkspaces(prev, workspaceId, sessionId, hint));
+  }, []);
+
   // Merge two tabs into one workspace. When one of them already belongs to a
   // workspace, that workspace (and its id) is reused instead of dissolving
   // and recreating: the id is what workspace-scoped AI chats bind to, so
@@ -1106,6 +1147,25 @@ export const useSessionState = ({
     setWorkspaces(prev => setWorkspaceFocusedSessionId(prev, workspaceId, sessionId));
   }, []);
 
+  // Issue #4098 phase 2: pin the AI chat a workspace scope is anchored to.
+  // Written by the AI side panel when a chat becomes active in the workspace
+  // scope; consumed by the non-positional fallbacks and persisted to the
+  // session restore snapshot.
+  const setWorkspaceAnchorChat = useCallback((workspaceId: string, chatId: string | null) => {
+    setWorkspaces(prev => {
+      const index = prev.findIndex(ws => ws.id === workspaceId);
+      if (index < 0) return prev;
+      if (prev[index].anchorChatId === (chatId ?? undefined)) return prev;
+      const next = prev.slice();
+      next[index] = chatId
+        ? { ...prev[index], anchorChatId: chatId }
+        : Object.fromEntries(
+            Object.entries(prev[index]).filter(([key]) => key !== 'anchorChatId'),
+          ) as Workspace;
+      return next;
+    });
+  }, []);
+
   const reorderWorkspaceSessions = useCallback((
     workspaceId: string,
     draggedSessionId: string,
@@ -1435,18 +1495,16 @@ export const useSessionState = ({
       sessions: sessionsRef.current,
       workspaces: workspacesRef.current,
       sessionId,
+      aiSessions: getAISessionsSnapshot().sessions.length > 0
+        ? getAISessionsSnapshot().sessions
+        : getPersistedAiSessionsSnapshot(),
     });
     if (!result.changed) return;
 
     setWorkspaces(result.workspaces);
     setSessions(result.sessions);
     setTabOrder((prevTabOrder) => {
-      const replacedOrder = replaceDissolvedWorkspaceTabOrder(
-        prevTabOrder,
-        result.dissolvedWorkspaceId,
-        result.replacementTabIds,
-      );
-      if (!tabInsertionTarget) return replacedOrder;
+      if (!tabInsertionTarget) return prevTabOrder;
 
       const allTabIds = [
         ...result.sessions.filter((s) => !s.workspaceId).map((s) => s.id),
@@ -1455,7 +1513,7 @@ export const useSessionState = ({
         ...(tabInsertionTarget.additionalTabIds ?? []),
       ];
       return reorderWorkTabIds(
-        replacedOrder,
+        prevTabOrder,
         allTabIds,
         sessionId,
         tabInsertionTarget.tabId,
@@ -1515,6 +1573,7 @@ export const useSessionState = ({
     createWorkspaceFromTargets,
     createWorkspaceFromSessions,
     addSessionToWorkspace,
+    moveWorkspacePane,
     removeSessionFromWorkspace,
     appendHostToWorkspace,
     appendHostToWorkspaceConfirmed,
@@ -1523,6 +1582,7 @@ export const useSessionState = ({
     splitSession,
     toggleWorkspaceViewMode,
     setWorkspaceFocusedSession,
+    setWorkspaceAnchorChat,
     reorderWorkspaceSessions,
     moveFocusInWorkspace,
     runSnippet,

application/state/useSessionStateMergedWorkspaceTitle.test.ts

@@ -4,6 +4,10 @@ import React from "react";
 import { act, create, type ReactTestRenderer } from "react-test-renderer";
 
 import { useSessionState } from "./useSessionState.ts";
+import { installTestLocalStorage } from "./testSupport/localStorage.ts";
+import { collectSessionIds } from "../../domain/workspace.ts";
+
+test.beforeEach((t) => { t.after(installTestLocalStorage()); });
 
 type SessionState = ReturnType<typeof useSessionState>;
 
@@ -121,6 +125,15 @@ test("merged tab titles follow the workspace lifecycle until the user renames it
   assert.equal(workspace(workspaceId).title, "Pinned");
   assert.equal(workspace(workspaceId).generatedTitle, false);
 
+  await act(async () => { current().closeSession(firstSessionId); });
+  assert.equal(workspace(workspaceId).title, "Pinned");
+  assert.deepEqual(collectSessionIds(workspace(workspaceId).root), [secondSessionId]);
+  assert.equal(current().sessions.find(session => session.id === secondSessionId)?.workspaceId, workspaceId);
+  await act(async () => { current().closeSession(secondSessionId); });
+  assert.equal(workspace(workspaceId).title, "Pinned");
+  assert.equal(workspace(workspaceId).generatedTitle, false);
+  assert.deepEqual(collectSessionIds(workspace(workspaceId).root), []);
+
   let leftBaseSessionId = "";
   let leftJoiningSessionId = "";
   await act(async () => {

application/state/useSettingsState.ts

@@ -1231,6 +1231,15 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     return () => mql.removeEventListener('change', handler);
   }, []);
 
+  // Listen for system theme changes from main process (fallback when matchMedia doesn't fire)
+  useEffect(() => {
+    const bridge = netcattyBridge.get();
+    if (!bridge?.onSystemThemeChanged) return;
+    return bridge.onSystemThemeChanged((payload) => {
+      setSystemPreference(payload.isDark ? 'dark' : 'light');
+    });
+  }, []);
+
   useLayoutEffect(() => {
     localStorageAdapter.writeString(STORAGE_KEY_UI_LANGUAGE, uiLanguage);
     document.documentElement.lang = uiLanguage;

application/state/useTerminalDirectorySession.test.ts

@@ -0,0 +1,95 @@
+import assert from 'node:assert/strict';
+import test, { type TestContext } from 'node:test';
+import React from 'react';
+import { act, create, type ReactTestRenderer } from 'react-test-renderer';
+import type { Host } from '../../domain/models';
+import { getTerminalDirectory, observeTerminalDirectory } from './terminalDirectoryRegistry';
+import { useTerminalDirectorySession } from './useTerminalDirectorySession';
+import { useComposeDirectoryPicker } from './useComposeDirectoryPicker';
+
+type SessionProps = Parameters<typeof useTerminalDirectorySession>[0];
+
+Object.assign(globalThis, { IS_REACT_ACT_ENVIRONMENT: true });
+
+function installBridge(t: TestContext, getAppInfo?: NetcattyBridge['getAppInfo']) {
+  const previous = Object.getOwnPropertyDescriptor(globalThis, 'window');
+  let probes = 0; let lists = 0;
+  Object.defineProperty(globalThis, 'window', { configurable: true, value: { netcatty: {
+    getAppInfo,
+    getSessionPwd: async () => { probes++; return { success: true, cwd: '/actual' }; },
+    listLocalDir: async () => { lists++; return []; },
+  } } });
+  t.after(() => {
+    if (previous) Object.defineProperty(globalThis, 'window', previous);
+    else Reflect.deleteProperty(globalThis, 'window');
+  });
+  return { counts: () => ({ probes, lists }) };
+}
+
+const options = (id: string, protocol = 'local', shellType = 'posix'): SessionProps => ({
+  sessionId: id, status: 'connected',
+  host: { id, label: 'Test', hostname: 'host', username: 'me', protocol } as Host,
+  shellType, getBackendId: () => id, isReady: () => true, publish() {},
+});
+
+for (const wrapper of ['wsl-Ubuntu', 'git-bash', 'cygwin']) {
+  test(`Windows ${wrapper} reports directory navigation unavailable and performs no reads`, async t => {
+    const bridge = installBridge(t, async () => ({ name: 'Netcatty', version: 'test', platform: 'win32' }));
+    const id = 'windows-' + wrapper;
+    let model!: ReturnType<typeof useComposeDirectoryPicker>;
+    function Harness() {
+      const props = options(id);
+      props.host = { ...props.host, localShell: wrapper };
+      useTerminalDirectorySession(props);
+      model = useComposeDirectoryPicker(id);
+      return null;
+    }
+    let root!: ReactTestRenderer;
+    await act(async () => { root = create(React.createElement(Harness)); });
+    t.after(async () => { await act(async () => { root.unmount(); }); });
+    assert.equal(getTerminalDirectory(id), null);
+    assert.equal(model.available, false);
+    await act(async () => { model.setOpen(true); await model.refresh(); });
+    assert.equal(model.error, 'unavailable');
+    assert.deepEqual(bridge.counts(), { probes: 0, lists: 0 });
+  });
+}
+
+for (const platform of ['linux', 'darwin']) {
+  test(`local POSIX directory controller registers on ${platform}`, async t => {
+    installBridge(t, async () => ({ name: 'Netcatty', version: 'test', platform }));
+    const id = 'local-' + platform;
+    function Harness() { useTerminalDirectorySession(options(id)); return null; }
+    let root!: ReactTestRenderer;
+    await act(async () => { root = create(React.createElement(Harness)); });
+    t.after(async () => { await act(async () => { root.unmount(); }); });
+    assert.ok(getTerminalDirectory(id));
+  });
+}
+
+test('Windows SSH sessions do not inherit the local cwd platform limitation', async t => {
+  let platformQueries = 0;
+  installBridge(t, async () => { platformQueries++; return { name: 'Netcatty', version: 'test', platform: 'win32' }; });
+  const id = 'windows-ssh';
+  function Harness() { useTerminalDirectorySession(options(id, 'ssh')); return null; }
+  let root!: ReactTestRenderer;
+  await act(async () => { root = create(React.createElement(Harness)); });
+  t.after(async () => { await act(async () => { root.unmount(); }); });
+  assert.ok(getTerminalDirectory(id));
+  assert.equal(platformQueries, 0);
+});
+
+test('a late platform query cannot register a disconnected terminal', async t => {
+  let finish!: (info: { name: string; version: string; platform: string }) => void;
+  installBridge(t, () => new Promise(resolve => { finish = resolve; }));
+  const id = 'disconnected-during-platform-query';
+  const stopObserving = observeTerminalDirectory(id);
+  t.after(stopObserving);
+  function Harness({ status }: { status: string }) { useTerminalDirectorySession({ ...options(id), status }); return null; }
+  let root!: ReactTestRenderer;
+  await act(async () => { root = create(React.createElement(Harness, { status: 'connected' })); });
+  await act(async () => { root.update(React.createElement(Harness, { status: 'disconnected' })); });
+  await act(async () => { finish({ name: 'Netcatty', version: 'test', platform: 'linux' }); });
+  assert.equal(getTerminalDirectory(id), null);
+  await act(async () => { root.unmount(); });
+});

application/state/useTerminalDirectorySession.ts

@@ -0,0 +1,56 @@
+import { useEffect, useRef } from 'react';
+import type { Host } from '../../domain/models';
+import { classifyDistroId, hostRestrictsExtraSshChannels } from '../../domain/host';
+import { netcattyBridge } from '../../infrastructure/services/netcattyBridge';
+import { createTerminalDirectoryIO } from '../../infrastructure/services/terminalDirectory';
+import { createTerminalDirectoryController } from './terminalDirectoryController';
+import { registerTerminalDirectory } from './terminalDirectoryRegistry';
+
+export function useTerminalDirectorySession(options: {
+  sessionId: string;
+  status: string;
+  host: Host;
+  shellType?: string;
+  getBackendId: () => string | null;
+  isReady: () => boolean;
+  publish: (cwd: string) => void;
+}) {
+  const live = useRef(options);
+  live.current = options;
+  const { sessionId, status, shellType, host } = options;
+  const local = host.protocol === 'local';
+  const supported = (local || ((host.protocol ?? 'ssh') === 'ssh' && !host.moshEnabled && !host.etEnabled))
+    && shellType !== 'powershell' && shellType !== 'cmd'
+    && host.deviceType !== 'network' && classifyDistroId(host.distro) !== 'network-device'
+    && !hostRestrictsExtraSshChannels(host);
+  useEffect(() => {
+    const bridge = netcattyBridge.get();
+    const backendId = live.current.getBackendId();
+    if (!bridge || !backendId || status !== 'connected' || !supported) return;
+    let active = true;
+    const isCurrent = () => active && live.current.status === 'connected' && live.current.getBackendId() === backendId;
+    let unregister = () => {};
+    const register = () => {
+      if (!isCurrent()) return;
+      const controller = createTerminalDirectoryController({
+        sessionId,
+        io: createTerminalDirectoryIO(bridge, backendId, {
+          local, hostname: host.hostname, username: host.username || 'root', port: host.port,
+          encoding: host.sftpEncoding,
+        }, isCurrent),
+        isCurrent,
+        isReady: () => live.current.isReady(),
+        publish: cwd => live.current.publish(cwd),
+      });
+      unregister = registerTerminalDirectory(sessionId, controller);
+    };
+    if (local) {
+      // POSIX wrappers on Windows still use win32 PTYs. Neither their cwd nor
+      // their path namespace is supported by readLocalSessionCwd/local FS.
+      void bridge.getAppInfo?.().then(info => {
+        if (info.platform === 'darwin' || info.platform === 'linux') register();
+      }).catch(() => {});
+    } else register();
+    return () => { active = false; unregister(); };
+  }, [sessionId, status, supported, local, host.hostname, host.username, host.port, host.sftpEncoding, shellType]);
+}

application/syncPayload.aiSessions.test.ts

@@ -8,6 +8,8 @@ import React from 'react';
 import { act, create, type ReactTestRenderer } from 'react-test-renderer';
 import { getAgentRuntime } from '../infrastructure/ai/harness/globalAgentRuntime';
 import { useAIChatStreaming, type UseAIChatStreamingReturn } from './state/useAIChatStreaming';
+import { installFakeIndexedDb } from './state/testSupport/fakeIndexedDb';
+import { idbPutSessions, openAiSessionsIdb } from './state/aiSessionIdbStorage';
 
 installBrowserLockFixture();
 
@@ -43,7 +45,47 @@ function save(sessions: AISession[], enabled = true) {
   storage.set(keys.STORAGE_KEY_AI_SESSIONS, JSON.stringify(sessions));
   storage.set(keys.STORAGE_KEY_CLOUD_SYNC_AI_SESSIONS, JSON.stringify({ enabled }));
 }
-test.beforeEach(() => { storage.clear(); save([], false); });
+test.beforeEach(() => {
+  storage.clear();
+  save([], false);
+  snapshots.__resetIdbPersistenceForTests();
+});
+test.afterEach(() => {
+  snapshots.__resetIdbPersistenceForTests();
+});
+
+// Issue #4125 review P1①: a sync round that runs before the boot hydration
+// has settled must not collect (and persist) the stale legacy store — it
+// would overwrite newer IndexedDB records with pre-migration data.
+test('a sync round before boot hydration skips chat collection and never overwrites IndexedDB with stale legacy data', async () => {
+  const idb = installFakeIndexedDb();
+  try {
+    snapshots.__resetIdbPersistenceForTests();
+    snapshots.__resetAiSessionsHydrationForTests(); // boot load still pending
+    const newer = { ...session(), title: 'Newer IndexedDB copy', updatedAt: 9 };
+    await idbPutSessions(await openAiSessionsIdb(), [newer]);
+    // Stale pre-migration copy left in the read-only legacy key.
+    storage.set(keys.STORAGE_KEY_AI_SESSIONS, JSON.stringify([{ ...session(), title: 'Stale legacy copy', updatedAt: 1 }]));
+    storage.set(keys.STORAGE_KEY_CLOUD_SYNC_AI_SESSIONS, JSON.stringify({ enabled: true }));
+    snapshots.setLatestAISessionsSnapshot(null as unknown as AISession[]);
+    // Pre-hydration collection skips the round entirely.
+    assert.equal(collectAiSessionsForSync(), undefined);
+    await snapshots.__flushIdbWritesForTests();
+    assert.equal(
+      idb.db.dumpStore('sessions').find((s) => (s as AISession).id === 'chat')?.title,
+      'Newer IndexedDB copy',
+    );
+    // After hydration the collector returns the live snapshot again.
+    snapshots.markAiSessionsHydrationComplete();
+    const hydrated = [newer];
+    snapshots.seedLastPersistedSessions(hydrated);
+    snapshots.setLatestAISessionsSnapshot(hydrated);
+    assert.equal(collectAiSessionsForSync()?.[0].title, 'Newer IndexedDB copy');
+  } finally {
+    idb.restore();
+    snapshots.__resetIdbPersistenceForTests();
+  }
+});
 
 test('actual manual upload and auto collector honor consent and explicit empty', async () => {
   save([session()], false);
@@ -74,23 +116,16 @@ test('sync persistence survives restart beyond the local-only history limits', (
   assert.equal(afterRestart[0].messages.length, 201);
   save(many, false);
   assert.equal(snapshots.writeSessionsForStorage(many), true);
-  const localOnly = JSON.parse(storage.get(keys.STORAGE_KEY_AI_SESSIONS)!);
-  assert.equal(localOnly.length, 50);
+  // Issue #4123: the persisted set now lives in IndexedDB (per-record
+  // writes); the legacy localStorage key is a read-only fallback. The
+  // session-count cap rose to 1000, so all 51 chats survive retention —
+  // only the per-session message cap (200) still trims.
+  const localOnly = snapshots.getPersistedAiSessionsSnapshot();
+  assert.equal(localOnly.length, 51);
   assert.equal(localOnly[0].messages.length, 200);
 });
 
-test('sync collection after restart includes overflow before clearing it', () => {
-  const primary = session();
-  const overflow = { ...session(), id: 'overflow-chat', updatedAt: 1 };
-  save([primary], true);
-  storage.set(keys.STORAGE_KEY_AI_SESSIONS_OVERFLOW, JSON.stringify([overflow]));
-  snapshots.setLatestAISessionsSnapshot(null as unknown as AISession[]);
-  assert.deepEqual(collectAiSessionsForSync()?.map(value => value.id), [primary.id, overflow.id]);
-  assert.equal(storage.has(keys.STORAGE_KEY_AI_SESSIONS_OVERFLOW), false);
-  assert.deepEqual(JSON.parse(storage.get(keys.STORAGE_KEY_AI_SESSIONS)!).map((value: AISession) => value.id), [primary.id, overflow.id]);
-});
-
-test('failed history persistence refuses upload without pruning the cloud representation', async () => {
+test('legacy localStorage quota failures no longer block sync upload', async () => {
   save([session()]);
   const original = globalThis.localStorage.setItem;
   globalThis.localStorage.setItem = (key, value) => {
@@ -99,8 +134,12 @@ test('failed history persistence refuses upload without pruning the cloud repres
   };
   snapshots.setLatestAISessionsSnapshot([{ ...session(), title: 'Unsaved change' }]);
   try {
-    await assert.rejects(buildCloudSyncPayload(vault, [], { collectPluginSidecars: () => undefined }), /persist|save/i);
-    assert.equal(JSON.parse(storage.get(keys.STORAGE_KEY_AI_SESSIONS)!)[0].title, 'Chat');
+    // Persistence moved to IndexedDB (issue #4123), so the legacy key's
+    // quota can no longer fail the collect step; the in-memory snapshot is
+    // the source of truth for the upload.
+    const cloud = await buildCloudSyncPayload(vault, [], { collectPluginSidecars: () => undefined });
+    assert.equal(cloud.aiSessions?.[0].title, 'Unsaved change');
+    assert.equal(JSON.stringify(cloud).includes('cHJpdmF0ZQ=='), false);
     const backup = buildLocalVaultPayload(vault);
     assert.equal(backup.aiSessions?.[0].title, 'Unsaved change');
     assert.equal(backup.aiSessions?.[0].messages[0].attachments?.[0].base64Data, 'cHJpdmF0ZQ==');
@@ -164,7 +203,7 @@ test('download publishes immediately and keeps local attachment bytes on a newer
   assert.equal(current.messages[0].content, 'Updated');
   assert.equal(current.messages[0].attachments?.[0].base64Data, 'cHJpdmF0ZQ==');
   assert.equal(snapshots.latestAISessionsSnapshot?.[0], current);
-  assert.equal(JSON.parse(storage.get(keys.STORAGE_KEY_AI_SESSIONS)!)[0].messages[0].content, 'Updated');
+  assert.equal(snapshots.getPersistedAiSessionsSnapshot()[0].messages[0].content, 'Updated');
 });
 
 test('restoring an old backup without chat leaves current chats alone', async () => {
@@ -174,7 +213,7 @@ test('restoring an old backup without chat leaves current chats alone', async ()
     prepareConvergentRestore: async () => async () => {},
   });
   assert.deepEqual(snapshots.latestAISessionsSnapshot, [local]);
-  assert.deepEqual(JSON.parse(storage.get(keys.STORAGE_KEY_AI_SESSIONS)!), [local]);
+  assert.deepEqual(snapshots.getPersistedAiSessionsSnapshot(), [local]);
 });
 
 test('authoritative cloud session removal stays removed in the next upload', async () => {
@@ -202,6 +241,9 @@ test('replacement stops active turns and waits for finalizers before persisting
       const local = { ...session(), messages: [...session().messages,
         { id: 'reply', role: 'assistant' as const, content: 'Partial', timestamp: 2, executionStatus: 'running' as const }] };
       save([local]);
+      // Seed the per-record diff baseline so the only 'persist' marker in
+      // this scenario is the final replacement write (issue #4123).
+      snapshots.seedLastPersistedSessions([local]);
       hook!.abortControllersRef.current.set('chat', controller);
       await act(async () => { hook!.setStreamingForScope('chat', true); });
       Object.assign(window, { netcatty: {
@@ -216,15 +258,24 @@ test('replacement stops active turns and waits for finalizers before persisting
           { ...local.messages[1], content: 'Settled', executionStatus: 'cancelled' }] }]);
         order.push('settled');
       });
-      globalThis.localStorage.setItem = (key, value) => { if (key === keys.STORAGE_KEY_AI_SESSIONS) order.push('persist'); original(key, value); };
+      // Issue #4123: session persistence is an IndexedDB commit now; the
+      // 'persist' marker fires when the record lands in the store.
+      globalThis.localStorage.setItem = original;
+      const idb = installFakeIndexedDb({ onOperation: (store, _op) => {
+        // Both puts and deletes are persistence commits for the sessions store.
+        if (store === 'sessions') order.push('persist');
+      } });
       const incoming = { ...session(), updatedAt: 3, messages: [...session().messages,
         { id: 'remote', role: 'user' as const, content: 'Remote', timestamp: 3 }] };
       await applyLocalVaultPayload(remotePayload(remove ? [] : [incoming]), { importVaultData: () => undefined }, {
         prepareConvergentRestore: async () => async () => {},
       });
+      await snapshots.__flushIdbWritesForTests();
+      idb.restore();
+      snapshots.__resetIdbPersistenceForTests();
       assert.ok(order.indexOf('cancel') < order.indexOf('settled'));
       assert.ok(order.indexOf('settled') < order.indexOf('persist'));
-      assert.ok(order.indexOf('persist') < order.indexOf('cleanup'));
+      assert.ok(order.includes('cleanup'));
       assert.equal(hook!.abortControllersRef.current.has('chat'), false);
       if (remove) assert.deepEqual(getAISessionsSnapshot().sessions, []);
       else assert.equal(getAISessionsSnapshot().sessions[0].messages.at(-1)?.content, 'Remote');
@@ -268,7 +319,7 @@ test('cloud sync preserves an active trimmed conversation and its native thread'
       assert.equal(controller.signal.aborted, false);
       assert.deepEqual(calls, []);
       assert.deepEqual(getAISessionsSnapshot().sessions, [local]);
-      assert.equal(JSON.parse(storage.get(keys.STORAGE_KEY_AI_SESSIONS)!)[0].externalSessionId, 'native-thread');
+      assert.equal(snapshots.getPersistedAiSessionsSnapshot()[0].externalSessionId, 'native-thread');
     }
   } finally {
     hook!.abortControllersRef.current.delete('chat');
@@ -299,7 +350,7 @@ test('cloud downloads respect local chat opt-in while still applying vault data'
   await applySyncPayload(downloaded, { importVaultData: () => { vaultImports++; } });
   assert.equal(vaultImports, 1);
   assert.deepEqual(snapshots.latestAISessionsSnapshot, []);
-  assert.deepEqual(JSON.parse(storage.get(keys.STORAGE_KEY_AI_SESSIONS)!), []);
+  assert.deepEqual(snapshots.getPersistedAiSessionsSnapshot(), []);
   save([], true);
   await applySyncPayload(downloaded, { importVaultData: () => { vaultImports++; } });
   assert.equal(vaultImports, 2);

application/syncPayload.ts

@@ -50,8 +50,9 @@ import { decryptField, encryptField } from '../infrastructure/persistence/secure
 import { sanitizeQuickMessages } from '../infrastructure/ai/quickMessages';
 import { emitAIStateChanged } from './state/aiStateEvents';
 import {
+  isAiSessionsHydrationComplete,
   latestAISessionsSnapshot,
-  readSessionsFromStorage,
+  getPersistedAiSessionsSnapshot,
   setLatestAISessionsSnapshot,
   writeSessionsForStorage,
   cleanupSdkAgentSessions,
@@ -1065,6 +1066,12 @@ function pruneOrphanPerAgentBindings(): void {
 export function collectAiSessionsForSync(): SyncPayload['aiSessions'] {
   const enabled = localStorageAdapter.read<{ enabled?: boolean }>(STORAGE_KEY_CLOUD_SYNC_AI_SESSIONS);
   if (enabled?.enabled !== true) return undefined;
+  // Issue #4125 review P1①: never collect before the boot hydration has
+  // settled. A pre-hydration collect falls back to the stale legacy
+  // localStorage store and the writeSessionsForStorage() call below would
+  // overwrite newer IndexedDB records with pre-migration data. Skip this
+  // sync round; the next auto-sync picks up the hydrated store.
+  if (!isAiSessionsHydrationComplete()) return undefined;
   const sessions = collectLocalAiSessions();
   if (!writeSessionsForStorage(sessions)) {
     throw new Error('Unable to persist chat history for cloud sync');
@@ -1074,7 +1081,7 @@ export function collectAiSessionsForSync(): SyncPayload['aiSessions'] {
 
 function collectLocalAiSessions(): NonNullable<SyncPayload['aiSessions']> {
   return latestAISessionsSnapshot
-    ?? readSessionsFromStorage();
+    ?? getPersistedAiSessionsSnapshot();
 }
 
 /** Build the portable payload; device-local data is added by the backup builder. */

build/installer.nsh

@@ -22,9 +22,39 @@
   WriteRegStr SHCTX "Software\Classes\Directory\Background\shell\Netcatty" "MUIVerb" "Open in Netcatty"
   WriteRegStr SHCTX "Software\Classes\Directory\Background\shell\Netcatty" "Icon" "$INSTDIR\${APP_EXECUTABLE_FILENAME},0"
   WriteRegStr SHCTX "Software\Classes\Directory\Background\shell\Netcatty\command" "" '"$INSTDIR\${APP_EXECUTABLE_FILENAME}" -- --open-terminal-path="%V."'
+
+  ; #4204: Windows Default Apps requires Capabilities/RegisteredApplications
+  ; to list URL handlers; Electron's bare scheme keys are not sufficient.
+  WriteRegStr SHCTX "Software\Classes\Netcatty.SSH" "" "URL:ssh Protocol"
+  WriteRegStr SHCTX "Software\Classes\Netcatty.SSH" "URL Protocol" ""
+  WriteRegStr SHCTX "Software\Classes\Netcatty.SSH\DefaultIcon" "" '"$INSTDIR\${APP_EXECUTABLE_FILENAME}",0'
+  WriteRegStr SHCTX "Software\Classes\Netcatty.SSH\shell\open\command" "" '"$INSTDIR\${APP_EXECUTABLE_FILENAME}" "%1"'
+
+  WriteRegStr SHCTX "Software\Classes\Netcatty.Telnet" "" "URL:telnet Protocol"
+  WriteRegStr SHCTX "Software\Classes\Netcatty.Telnet" "URL Protocol" ""
+  WriteRegStr SHCTX "Software\Classes\Netcatty.Telnet\DefaultIcon" "" '"$INSTDIR\${APP_EXECUTABLE_FILENAME}",0'
+  WriteRegStr SHCTX "Software\Classes\Netcatty.Telnet\shell\open\command" "" '"$INSTDIR\${APP_EXECUTABLE_FILENAME}" "%1"'
+
+  WriteRegStr SHCTX "Software\Classes\Netcatty.JMS" "" "URL:jms Protocol"
+  WriteRegStr SHCTX "Software\Classes\Netcatty.JMS" "URL Protocol" ""
+  WriteRegStr SHCTX "Software\Classes\Netcatty.JMS\DefaultIcon" "" '"$INSTDIR\${APP_EXECUTABLE_FILENAME}",0'
+  WriteRegStr SHCTX "Software\Classes\Netcatty.JMS\shell\open\command" "" '"$INSTDIR\${APP_EXECUTABLE_FILENAME}" "%1"'
+
+  WriteRegStr SHCTX "Software\Netcatty\Capabilities" "ApplicationName" "Netcatty"
+  WriteRegStr SHCTX "Software\Netcatty\Capabilities" "ApplicationDescription" "Open SSH, Telnet and JMS links in Netcatty."
+  WriteRegStr SHCTX "Software\Netcatty\Capabilities" "ApplicationIcon" '"$INSTDIR\${APP_EXECUTABLE_FILENAME}",0'
+  WriteRegStr SHCTX "Software\Netcatty\Capabilities\URLAssociations" "ssh" "Netcatty.SSH"
+  WriteRegStr SHCTX "Software\Netcatty\Capabilities\URLAssociations" "telnet" "Netcatty.Telnet"
+  WriteRegStr SHCTX "Software\Netcatty\Capabilities\URLAssociations" "jms" "Netcatty.JMS"
+  WriteRegStr SHCTX "Software\RegisteredApplications" "Netcatty" "Software\Netcatty\Capabilities"
 !macroend
 
 !macro customUnInstall
   DeleteRegKey SHCTX "Software\Classes\Directory\shell\Netcatty"
   DeleteRegKey SHCTX "Software\Classes\Directory\Background\shell\Netcatty"
+  DeleteRegKey SHCTX "Software\Classes\Netcatty.SSH"
+  DeleteRegKey SHCTX "Software\Classes\Netcatty.Telnet"
+  DeleteRegKey SHCTX "Software\Classes\Netcatty.JMS"
+  DeleteRegKey SHCTX "Software\Netcatty\Capabilities"
+  DeleteRegValue SHCTX "Software\RegisteredApplications" "Netcatty"
 !macroend

components/AIChatSidePanel.tsx

@@ -50,6 +50,7 @@ import {
   tryBeginSendForKey,
 } from './ai/draftSendGate';
 import { draftsByScopeEqualIgnoringComposerText, selectDraftForAgentSwitch } from '../application/state/aiDraftState';
+import { latestAIActiveSessionMapSnapshot, latestAISessionsSnapshot } from '../application/state/aiStateSnapshots';
 import { sanitizeContextWindow } from '../infrastructure/ai/contextCompaction';
 import {
   buildPromptWithTerminalSelectionAttachments,
@@ -316,6 +317,7 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
   scopeHostIds,
   scopeLabel,
   focusedSessionId,
+  onSetWorkspaceAnchorChat,
   workspaces = [],
   terminalSessions = [],
   liveScopeTargetIds,
@@ -444,9 +446,16 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
     preferredTerminalId: focusedSessionId,
     visibleSessionIds: visibleHistorySessionIds,
   });
+  // Issue #4098 phase 2: this workspace's anchored chat — used by the panel
+  // view resolver before any positional fallback could apply.
+  const workspaceAnchorChatId = scopeType === 'workspace'
+    ? workspaces.find((workspace) => workspace.id === scopeTargetId)?.anchorChatId
+    : undefined;
+  // getScopedHistorySessions orders by scope match first, recency second.
+  const preferredHistorySessionId = historySessions[0]?.id ?? null;
   const normalizedPanelView = useMemo<AIPanelView>(
-    () => resolveDisplayedPanelView(explicitPanelView, currentDraft != null, historySessions, persistedSessionId, scopeType),
-    [explicitPanelView, currentDraft, historySessions, persistedSessionId, scopeType],
+    () => resolveDisplayedPanelView(explicitPanelView, currentDraft != null, historySessions, persistedSessionId, scopeType, workspaceAnchorChatId, preferredHistorySessionId),
+    [explicitPanelView, currentDraft, historySessions, persistedSessionId, scopeType, workspaceAnchorChatId, preferredHistorySessionId],
   );
   const activeSession = useMemo(
     () => resolveDisplayedSession(normalizedPanelView, historySessions),
@@ -641,6 +650,21 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
     }, { initialDelayMs: 250 });
   }, [isVisible, terminalSessions, activeSessionId]);
 
+  // Workspace maintenance can retarget an inherited chat earlier in this same
+  // passive-effect flush. Before clearing a selection, recheck its membership
+  // against the synchronous snapshot instead of this render's old history.
+  const isSessionVisibleInCurrentScope = useCallback((sessionId: string) => (
+    getScopedHistorySessions(
+      latestAISessionsSnapshot ?? sessions,
+      scopeType,
+      scopeTargetId,
+      scopeHostIds,
+      activeTerminalSessionIds,
+      workspaceMemberTerminalIds,
+      latestAIActiveSessionMapSnapshot ?? activeSessionIdMap,
+    ).some((session) => session.id === sessionId)
+  ), [sessions, scopeType, scopeTargetId, scopeHostIds, activeTerminalSessionIds, workspaceMemberTerminalIds, activeSessionIdMap]);
+
   useEffect(() => {
     if (!isVisible) return;
     // Predicate must match normalizePanelView's list (scoped history), not the
@@ -648,16 +672,23 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
     if (!shouldForceDraftViewSync(
       explicitPanelView,
       normalizedPanelView,
-      (sessionId) => historySessions.some((session) => session.id === sessionId),
+      isSessionVisibleInCurrentScope,
     )) {
       return;
     }
     showDraftView(scopeKey);
-  }, [isVisible, normalizedPanelView, explicitPanelView, scopeKey, historySessions, showDraftView]);
+  }, [isVisible, normalizedPanelView, explicitPanelView, scopeKey, isSessionVisibleInCurrentScope, showDraftView]);
 
   useEffect(() => {
     if (!activeSession) return;
 
+    // Issue #4098 phase 2: a chat becoming active in the workspace scope pins
+    // the workspace's anchorChatId so member loss / restart resolve by id,
+    // never by position.
+    if (scopeType === 'workspace' && scopeTargetId && isVisible) {
+      onSetWorkspaceAnchorChat?.(scopeTargetId, activeSession.id);
+    }
+
     if (isVisible && activeSessionIdMap[scopeKey] !== activeSession.id) {
       setActiveSessionId(activeSession.id);
     }
@@ -665,18 +696,24 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
     activeSession,
     activeSessionIdMap,
     scopeKey,
+    scopeType,
+    scopeTargetId,
     isVisible,
+    onSetWorkspaceAnchorChat,
     setActiveSessionId,
   ]);
 
   useEffect(() => {
     if (!isVisible) return;
     if (normalizedPanelView.mode !== 'draft') return;
-    // Keep ownership while an explicit session is still displayable in this
-    // scope (normalize has not demoted it). Out-of-scope / missing ids clear.
+    // Keep a selection that maintenance just made displayable, but always
+    // honor an explicit New Chat draft. Out-of-scope / missing ids still clear.
+    const selectedSessionId = explicitPanelView?.mode === 'session'
+      ? explicitPanelView.sessionId : persistedSessionId;
     if (
-      explicitPanelView?.mode === 'session'
-      && historySessions.some((session) => session.id === explicitPanelView.sessionId)
+      explicitPanelView?.mode !== 'draft'
+      && selectedSessionId
+      && isSessionVisibleInCurrentScope(selectedSessionId)
     ) {
       return;
     }
@@ -686,7 +723,7 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
     isVisible,
     normalizedPanelView.mode,
     explicitPanelView,
-    historySessions,
+    isSessionVisibleInCurrentScope,
     persistedSessionId,
     setActiveSessionId,
   ]);
@@ -1788,6 +1825,8 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
         try {
           const existingExternalSessionId = currentSession?.externalSessionId;
           await sendToExternalAgent(sessionId, assistantMsgId, modelPrompt, agentConfig, abortController, modelAttachments, {
+            scopeType,
+            scopeTargetId,
             existingSessionId: existingExternalSessionId,
             updateExternalSessionId: updateSessionExternalSessionId,
             historyMessages: buildExternalAgentHistoryMessagesForBridge(currentSession?.messages ?? [], existingExternalSessionId),

components/AIChatSidePanel.types.ts

@@ -109,8 +109,10 @@ export interface AIChatSidePanelProps {
   scopeLabel?: string;
   /** Workspace focused pane; preferred when inheriting AI chat after merge. */
   focusedSessionId?: string;
-  /** Live workspaces, used to resolve workspace titles for `/chats`. */
-  workspaces?: Array<{ id: string; title: string }>;
+  /** Issue #4098 phase 2: pin the AI chat a workspace scope is anchored to. */
+  onSetWorkspaceAnchorChat?: (workspaceId: string, chatId: string | null) => void;
+  /** Live workspaces (with their anchor chat), used for scope titles and anchor resolution. */
+  workspaces?: Array<{ id: string; title: string; anchorChatId?: string }>;
   /** All currently live terminal (and workspace) scope target ids. */
   liveScopeTargetIds?: Set<string>;
 

components/CloudSyncSettings.tsx

@@ -35,6 +35,7 @@ import {
 import {
     initializePreparedConvergentMigration,
     prepareConvergentSyncMigration,
+    resolvePreparedConvergentMigrationConflict,
     type PreparedConvergentMigration,
 } from '../application/convergentSyncMigration';
 import type { ShrinkFinding } from '../domain/syncGuards';
@@ -358,6 +359,15 @@ const SyncDashboard: React.FC<SyncDashboardProps> = ({
         setConvergentBusy(true);
         setConvergentError(null);
         try {
+            if (preparedConvergentMigration && !sync.convergentSyncConfig.initialized) {
+                const prepared = resolvePreparedConvergentMigrationConflict(
+                    preparedConvergentMigration, addressKey, candidateDot,
+                );
+                setPreparedConvergentMigration(prepared);
+                setConvergentPreview(prepared.plan.preview);
+                toast.success(t('cloudSync.convergent.conflict.resolved'));
+                return;
+            }
             const { results } = await sync.resolveConvergentConflict(
                 addressKey,
                 candidateDot,
@@ -371,7 +381,7 @@ const SyncDashboard: React.FC<SyncDashboardProps> = ({
         } finally {
             setConvergentBusy(false);
         }
-    }, [onApplyConvergentPayload, sync, t]);
+    }, [onApplyConvergentPayload, preparedConvergentMigration, sync, t]);
 
     const handleDowngradeConvergent = useCallback(async () => {
         if (!window.confirm(t('cloudSync.convergent.downgrade.confirm'))) return;

components/HostDetailsAdvancedSections.tsx

@@ -49,11 +49,13 @@ export const HostDetailsAdvancedSections: React.FC<HostDetailsAdvancedSectionsPr
   showAlgorithmOverrides,
   setShowAlgorithmOverrides,
   chainedHosts,
+  hostChainInherited = false,
   setActiveSubPanel,
   clearHostChain,
   proxySummaryType,
   proxySummaryLabel,
   proxySummaryTooltip,
+  proxyInherited = false,
   clearProxyConfig,
 }) => {
   const inheritedDeviceType = effectiveGroupDefaults?.deviceType;
@@ -641,9 +643,16 @@ export const HostDetailsAdvancedSections: React.FC<HostDetailsAdvancedSectionsPr
           title={t("hostDetails.jumpHosts")}
           action={
             chainedHosts.length > 0 ? (
-              <Badge variant="secondary" className="text-xs">
-                {t("hostDetails.jumpHosts.hops", { count: chainedHosts.length })}
-              </Badge>
+              <div className="flex items-center gap-1">
+                {hostChainInherited && (
+                  <Badge variant="outline" className="text-xs text-muted-foreground">
+                    {t("vault.groups.details.inherited")}
+                  </Badge>
+                )}
+                <Badge variant="secondary" className="text-xs">
+                  {t("hostDetails.jumpHosts.hops", { count: chainedHosts.length })}
+                </Badge>
+              </div>
             ) : (
               <Badge variant="outline" className="text-xs text-muted-foreground">
                 {t("hostDetails.jumpHosts.direct")}
@@ -664,8 +673,10 @@ export const HostDetailsAdvancedSections: React.FC<HostDetailsAdvancedSectionsPr
                   />
                   <span className="text-xs text-muted-foreground">
                     {t("hostDetails.jumpHosts.hops", { count: chainedHosts.length })}
+                    {hostChainInherited ? ` · ${t("vault.groups.details.inherited")}` : ""}
                   </span>
                 </div>
+                {!hostChainInherited && (
                 <X
                   size={14}
                   className="text-muted-foreground hover:text-destructive flex-shrink-0"
@@ -674,6 +685,7 @@ export const HostDetailsAdvancedSections: React.FC<HostDetailsAdvancedSectionsPr
                     clearHostChain();
                   }}
                 />
+                )}
               </div>
               <div className="w-full space-y-1 pl-5">
                 {chainedHosts.slice(0, 5).map((h, idx) => (
@@ -735,7 +747,7 @@ export const HostDetailsAdvancedSections: React.FC<HostDetailsAdvancedSectionsPr
                 <X size={14} />
               </Button>
             </div>
-          ) : form.proxyConfig?.host || form.proxyConfig?.command || form.proxyProfileId ? (
+          ) : form.proxyConfig?.host || form.proxyConfig?.command || form.proxyProfileId || proxyInherited ? (
             <div className="w-full min-w-0 grid grid-cols-[minmax(0,1fr)_auto] items-center gap-1">
               <button
                 type="button"
@@ -750,6 +762,7 @@ export const HostDetailsAdvancedSections: React.FC<HostDetailsAdvancedSectionsPr
                     <TooltipTrigger asChild>
                       <span className="block min-w-0 overflow-hidden text-ellipsis whitespace-nowrap text-sm">
                         {proxySummaryLabel}
+                        {proxyInherited ? ` · ${t("vault.groups.details.inherited")}` : ""}
                       </span>
                     </TooltipTrigger>
                     <TooltipContent side="bottom" align="start" className="max-w-xs break-all">
@@ -758,6 +771,7 @@ export const HostDetailsAdvancedSections: React.FC<HostDetailsAdvancedSectionsPr
                   </Tooltip>
                 </TooltipProvider>
               </button>
+              {!proxyInherited && (
               <Button
                 type="button"
                 variant="ghost"
@@ -768,6 +782,7 @@ export const HostDetailsAdvancedSections: React.FC<HostDetailsAdvancedSectionsPr
               >
                 <X size={14} />
               </Button>
+              )}
             </div>
           ) : (
             <Button

components/HostDetailsPanel.helpers.ts

@@ -1,4 +1,5 @@
 import type { GroupConfig } from "../domain/models";
+import { applyGroupDefaults } from "../domain/groupConfig";
 import {
   findProxyProfile,
   hasIncompleteProxyIdentity,
@@ -157,3 +158,69 @@ export const prepareProxyConfigForSave = (params: {
     normalizedProxyConfig: normalizeManualProxyConfig(params.proxyConfig),
   };
 };
+
+
+export const EMPTY_CUSTOM_PROXY_DRAFT: ProxyConfig = { type: "http", host: "", port: 8080 };
+
+export const resolveDisplayProxyProfileId = (
+  form: Pick<Host, "directProxy" | "proxyProfileId" | "proxyConfig">,
+  inheritedProfileId?: string,
+): string | undefined => {
+  if (form.directProxy || form.proxyConfig !== undefined) return form.proxyProfileId;
+  return form.proxyProfileId ?? inheritedProfileId;
+};
+
+export const nextFormAfterSelectProxyProfile = (
+  prev: Host,
+  profileId: string | undefined,
+  groupDefaults?: Partial<GroupConfig>,
+): Host => {
+  const { proxyConfig: _proxyConfig, proxyProfileId: _proxyProfileId, directProxy: _directProxy, ...rest } = prev;
+  if (!profileId) {
+    const inheritedConfig = !prev.directProxy
+      && prev.proxyProfileId === undefined
+      && prev.proxyConfig === undefined
+      && groupDefaults
+      ? applyGroupDefaults(prev, groupDefaults).proxyConfig
+      : undefined;
+    return {
+      ...rest,
+      proxyConfig: prev.proxyConfig ?? inheritedConfig ?? EMPTY_CUSTOM_PROXY_DRAFT,
+    } as Host;
+  }
+  return { ...rest, proxyProfileId: profileId } as Host;
+};
+
+export const resolveFormHostChainIds = (
+  host: Host,
+  groupDefaults?: Partial<GroupConfig>,
+): string[] => {
+  if (host.hostChain !== undefined) return host.hostChain.hostIds || [];
+  if (!groupDefaults) return [];
+  return applyGroupDefaults(host, groupDefaults).hostChain?.hostIds || [];
+};
+
+export const nextFormAfterClearHostChain = (
+  prev: Host,
+  groupDefaults?: Partial<GroupConfig>,
+): Host => {
+  const groupWouldRestore = Boolean(
+    groupDefaults
+    && applyGroupDefaults({ ...prev, hostChain: undefined }, groupDefaults).hostChain?.hostIds?.length,
+  );
+  if (prev.hostChain === undefined || groupWouldRestore) {
+    return { ...prev, hostChain: { hostIds: [] } };
+  }
+  const { hostChain: _hostChain, ...rest } = prev;
+  return rest as Host;
+};
+
+export const nextFormAfterRemoveHostFromChain = (
+  prev: Host,
+  index: number,
+  groupDefaults?: Partial<GroupConfig>,
+): Host => {
+  const ids = resolveFormHostChainIds(prev, groupDefaults).filter((_, i) => i !== index);
+  if (ids.length > 0) return { ...prev, hostChain: { hostIds: ids } };
+  return nextFormAfterClearHostChain(prev, groupDefaults);
+};

components/HostDetailsPanel.proxyProfile.test.tsx

@@ -6,12 +6,17 @@ import { renderToStaticMarkup } from "react-dom/server";
 import { I18nProvider } from "../application/i18n/I18nProvider.tsx";
 import type { Host, Identity } from "../types.ts";
 import HostDetailsPanel, { parseOptionalPortInput } from "./HostDetailsPanel.tsx";
+import { applyGroupDefaults } from "../domain/groupConfig.ts";
 import {
   prepareProxyConfigForSave,
   prepareTelnetCredentialsForSave,
   resolvePrimaryProtocolSavePort,
   resolvePrimaryProtocolSwitchPort,
   validateProxyConfigForSave,
+  nextFormAfterSelectProxyProfile,
+  nextFormAfterClearHostChain,
+  nextFormAfterRemoveHostFromChain,
+  resolveDisplayProxyProfileId,
 } from "./HostDetailsPanel.helpers.ts";
 import { TooltipProvider } from "./ui/tooltip.tsx";
 
@@ -549,3 +554,198 @@ test("HostDetailsPanel expands notes when the host already has notes", () => {
     "expected notes to render after connection settings",
   );
 });
+
+const networkSshHost: Host = {
+  ...hostWithMissingProxyProfile,
+  proxyProfileId: undefined,
+  group: "network",
+};
+
+const jumpHost: Host = {
+  id: "jump-1",
+  label: "Bastion",
+  hostname: "bastion.example.com",
+  username: "root",
+  tags: [],
+  os: "linux",
+  port: 22,
+  protocol: "ssh",
+  authMethod: "password",
+  createdAt: 1,
+};
+
+const hostOwnedJump: Host = {
+  ...jumpHost,
+  id: "jump-host",
+  label: "Edge",
+  hostname: "edge.example.com",
+};
+
+const renderHostDetailsWithGroup = (
+  initialData: Host,
+  groupConfig: Record<string, unknown>,
+  extraHosts: Host[] = [],
+) =>
+  renderToStaticMarkup(
+    React.createElement(
+      I18nProvider,
+      { locale: "en" },
+      React.createElement(
+        TooltipProvider,
+        null,
+        React.createElement(HostDetailsPanel, {
+          initialData,
+          availableKeys: [],
+          identities: [],
+          proxyProfiles: [],
+          groups: ["network"],
+          managedSources: [],
+          allTags: [],
+          allHosts: extraHosts,
+          terminalThemeId: "default",
+          terminalFontSize: 14,
+          groupConfigs: [{ path: "network", ...groupConfig }],
+          onSave: () => {},
+          onCancel: () => {},
+        }),
+      ),
+    ),
+  );
+
+test("HostDetailsPanel displays inherited group HTTP proxy", () => {
+  const markup = renderHostDetailsWithGroup(networkSshHost, {
+    proxyConfig: { type: "http", host: "group-proxy.example.com", port: 8080 },
+  });
+
+  assert.match(markup, /group-proxy\.example\.com/);
+  assert.match(markup, /Inherited from group/);
+});
+
+test("HostDetailsPanel host proxy override wins over the group proxy", () => {
+  const markup = renderHostDetailsWithGroup({
+    ...networkSshHost,
+    proxyConfig: { type: "http", host: "host-proxy.example.com", port: 9090 },
+  }, {
+    proxyConfig: { type: "http", host: "group-proxy.example.com", port: 8080 },
+  });
+
+  assert.match(markup, /host-proxy\.example\.com/);
+  assert.doesNotMatch(markup, /group-proxy\.example\.com/);
+  assert.doesNotMatch(markup, /Inherited from group/);
+});
+
+test("HostDetailsPanel direct proxy hides inherited group proxy", () => {
+  const markup = renderHostDetailsWithGroup({
+    ...networkSshHost,
+    directProxy: true,
+  }, {
+    proxyConfig: { type: "http", host: "group-proxy.example.com", port: 8080 },
+  });
+
+  assert.match(markup, /Direct \(no proxy\)/);
+  assert.doesNotMatch(markup, /group-proxy\.example\.com/);
+});
+
+test("HostDetailsPanel displays inherited group jump hosts", () => {
+  const markup = renderHostDetailsWithGroup(networkSshHost, {
+    hostChain: { hostIds: ["jump-1"] },
+  }, [jumpHost]);
+
+  assert.match(markup, /bastion\.example\.com/);
+  assert.match(markup, /Inherited from group/);
+});
+
+test("HostDetailsPanel host jump-host override wins over the group chain", () => {
+  const markup = renderHostDetailsWithGroup({
+    ...networkSshHost,
+    hostChain: { hostIds: ["jump-host"] },
+  }, {
+    hostChain: { hostIds: ["jump-1"] },
+  }, [jumpHost, hostOwnedJump]);
+
+  assert.match(markup, /edge\.example\.com/);
+  assert.doesNotMatch(markup, /bastion\.example\.com/);
+  assert.doesNotMatch(markup, /Inherited from group/);
+});
+
+
+test("selecting Custom while inheriting a saved proxy keeps a custom draft instead of the profile", () => {
+  const group = { proxyProfileId: "office-proxy" };
+  const next = nextFormAfterSelectProxyProfile(networkSshHost, undefined, group);
+
+  assert.equal(next.proxyProfileId, undefined);
+  assert.equal(next.directProxy, undefined);
+  assert.deepEqual(next.proxyConfig, { type: "http", host: "", port: 8080 });
+  assert.equal(resolveDisplayProxyProfileId(next, "office-proxy"), undefined);
+  assert.equal(applyGroupDefaults(next, group).proxyProfileId, undefined);
+});
+
+test("removing the last hop of a multi-hop inherited chain keeps an empty override", () => {
+  const group = { hostChain: { hostIds: ["jump-1", "jump-host"] } };
+  const afterFirst = nextFormAfterRemoveHostFromChain(networkSshHost, 0, group);
+  assert.deepEqual(afterFirst.hostChain, { hostIds: ["jump-host"] });
+
+  const afterLast = nextFormAfterRemoveHostFromChain(afterFirst, 0, group);
+  assert.deepEqual(afterLast.hostChain, { hostIds: [] });
+  assert.deepEqual(applyGroupDefaults(afterLast, group).hostChain, { hostIds: [] });
+});
+
+test("clearing an inherited-only chain keeps an empty override instead of restoring group hops", () => {
+  const group = { hostChain: { hostIds: ["jump-1", "jump-host"] } };
+  const cleared = nextFormAfterClearHostChain(networkSshHost, group);
+  assert.deepEqual(cleared.hostChain, { hostIds: [] });
+  assert.deepEqual(applyGroupDefaults(cleared, group).hostChain, { hostIds: [] });
+});
+
+test("HostDetailsPanel custom proxy draft hides the inherited saved proxy", () => {
+  const markup = renderToStaticMarkup(
+    React.createElement(
+      I18nProvider,
+      { locale: "en" },
+      React.createElement(
+        TooltipProvider,
+        null,
+        React.createElement(HostDetailsPanel, {
+          initialData: {
+            ...networkSshHost,
+            proxyConfig: { type: "http", host: "", port: 8080 },
+          },
+          availableKeys: [],
+          identities: [],
+          proxyProfiles: [{
+            id: "office-proxy",
+            label: "Office Proxy",
+            config: { type: "http", host: "office-proxy.example.com", port: 8080 },
+            createdAt: 1,
+          }],
+          groups: ["network"],
+          managedSources: [],
+          allTags: [],
+          allHosts: [],
+          terminalThemeId: "default",
+          terminalFontSize: 14,
+          groupConfigs: [{ path: "network", proxyProfileId: "office-proxy" }],
+          onSave: () => {},
+          onCancel: () => {},
+        }),
+      ),
+    ),
+  );
+
+  assert.doesNotMatch(markup, /Office Proxy/);
+  assert.doesNotMatch(markup, /office-proxy\.example\.com/);
+  assert.doesNotMatch(markup, /Inherited from group/);
+});
+
+test("HostDetailsPanel empty jump-host override hides the inherited group chain", () => {
+  const markup = renderHostDetailsWithGroup({
+    ...networkSshHost,
+    hostChain: { hostIds: [] },
+  }, {
+    hostChain: { hostIds: ["jump-1", "jump-host"] },
+  }, [jumpHost, hostOwnedJump]);
+
+  assert.doesNotMatch(markup, /bastion\.example\.com/);
+  assert.doesNotMatch(markup, /edge\.example\.com/);
+  assert.doesNotMatch(markup, /Inherited from group/);
+});

components/HostDetailsPanel.tsx

@@ -55,6 +55,11 @@ import {
   resolvePrimaryProtocolSwitchPort,
   prepareTelnetCredentialsForSave,
   prepareProxyConfigForSave,
+  nextFormAfterSelectProxyProfile,
+  nextFormAfterClearHostChain,
+  nextFormAfterRemoveHostFromChain,
+  resolveFormHostChainIds,
+  resolveDisplayProxyProfileId,
 } from "./HostDetailsPanel.helpers";
 export { parseOptionalPortInput } from "./HostDetailsPanel.helpers";
 import { TerminalEncodingSelect } from "./TerminalEncodingSelect";
@@ -424,24 +429,34 @@ const HostDetailsPanel: React.FC<HostDetailsPanelPropsWithResize> = ({
   );
 
   const effectiveFormDistro = getEffectiveHostDistro(form);
+  const hasHostProxyOverride = form.directProxy === true
+    || form.proxyProfileId !== undefined
+    || form.proxyConfig !== undefined;
+  const displayProxyProfileId = resolveDisplayProxyProfileId(form, effectiveAuthHost.proxyProfileId);
+  const displayProxyConfig = form.directProxy
+    ? undefined
+    : (form.proxyConfig ?? effectiveAuthHost.proxyConfig);
   const selectedProxyProfile = useMemo(
-    () => proxyProfiles.find((profile) => profile.id === form.proxyProfileId),
-    [form.proxyProfileId, proxyProfiles],
+    () => proxyProfiles.find((profile) => profile.id === displayProxyProfileId),
+    [displayProxyProfileId, proxyProfiles],
   );
-  const hasMissingProxyProfile = Boolean(form.proxyProfileId && !selectedProxyProfile);
+  const hasMissingProxyProfile = Boolean(displayProxyProfileId && !selectedProxyProfile);
+  const proxyInherited = !hasHostProxyOverride && Boolean(
+    displayProxyProfileId || displayProxyConfig?.host || displayProxyConfig?.command,
+  ) && Boolean(effectiveGroupDefaults?.proxyProfileId || effectiveGroupDefaults?.proxyConfig);
   const proxySummaryType = hasMissingProxyProfile
     ? t("hostDetails.proxyPanel.missing")
-    : formatProxyConfigType(selectedProxyProfile?.config || form.proxyConfig) || "HTTP";
+    : formatProxyConfigType(selectedProxyProfile?.config || displayProxyConfig) || "HTTP";
   const proxySummaryLabel = hasMissingProxyProfile
     ? t("hostDetails.proxyPanel.missingSaved")
     : selectedProxyProfile
       ? selectedProxyProfile.label
-      : formatProxyConfigEndpoint(form.proxyConfig);
+      : formatProxyConfigEndpoint(displayProxyConfig);
   const proxySummaryTooltip = hasMissingProxyProfile
     ? t("hostDetails.proxyPanel.missingSaved")
     : selectedProxyProfile
       ? `${selectedProxyProfile.label} - ${formatProxyConfigEndpoint(selectedProxyProfile.config)}`
-      : `${formatProxyConfigType(form.proxyConfig)} ${formatProxyConfigEndpoint(form.proxyConfig)}`;
+      : `${formatProxyConfigType(displayProxyConfig)} ${formatProxyConfigEndpoint(displayProxyConfig)}`;
 
   const handleDistroModeChange = useCallback((mode: "auto" | "manual") => {
     setForm((prev) => ({
@@ -458,13 +473,19 @@ const HostDetailsPanel: React.FC<HostDetailsPanelPropsWithResize> = ({
     (field: keyof ProxyConfig, value: ProxyConfig[keyof ProxyConfig]) => {
       setForm((prev) => {
         const { proxyProfileId: _proxyProfileId, directProxy: _directProxy, ...rest } = prev;
+        const inheritedConfig = !prev.directProxy
+          && prev.proxyProfileId === undefined
+          && prev.proxyConfig === undefined
+          && effectiveGroupDefaults
+          ? applyGroupDefaults(prev, effectiveGroupDefaults).proxyConfig
+          : undefined;
         return {
           ...rest,
-          proxyConfig: updateProxyConfigField(prev.proxyConfig, field, value),
+          proxyConfig: updateProxyConfigField(prev.proxyConfig ?? inheritedConfig, field, value),
         } as Host;
       });
     },
-    [],
+    [effectiveGroupDefaults],
   );
 
   const clearProxyConfig = useCallback(() => {
@@ -475,12 +496,8 @@ const HostDetailsPanel: React.FC<HostDetailsPanelPropsWithResize> = ({
   }, []);
 
   const selectProxyProfile = useCallback((profileId: string | undefined) => {
-    setForm((prev) => {
-      const { proxyConfig: _proxyConfig, proxyProfileId: _proxyProfileId, directProxy: _directProxy, ...rest } = prev;
-      if (!profileId) return rest as Host;
-      return { ...rest, proxyProfileId: profileId } as Host;
-    });
-  }, []);
+    setForm((prev) => nextFormAfterSelectProxyProfile(prev, profileId, effectiveGroupDefaults));
+  }, [effectiveGroupDefaults]);
 
   const selectDirectProxy = useCallback(() => {
     setForm((prev) => {
@@ -493,24 +510,18 @@ const HostDetailsPanel: React.FC<HostDetailsPanelPropsWithResize> = ({
     setForm((prev) => ({
       ...prev,
       hostChain: {
-        hostIds: [...(prev.hostChain?.hostIds || []), hostId],
+        hostIds: [...resolveFormHostChainIds(prev, effectiveGroupDefaults), hostId],
       },
     }));
   };
 
   const removeHostFromChain = (index: number) => {
-    setForm((prev) => {
-      const ids = (prev.hostChain?.hostIds || []).filter((_, i) => i !== index);
-      return { ...prev, hostChain: ids.length > 0 ? { hostIds: ids } : undefined };
-    });
+    setForm((prev) => nextFormAfterRemoveHostFromChain(prev, index, effectiveGroupDefaults));
   };
 
   const clearHostChain = useCallback(() => {
-    setForm((prev) => {
-      const { hostChain: _hostChain, ...rest } = prev;
-      return rest as Host;
-    });
-  }, []);
+    setForm((prev) => nextFormAfterClearHostChain(prev, effectiveGroupDefaults));
+  }, [effectiveGroupDefaults]);
 
   const [newEnvName, setNewEnvName] = useState("");
   const [newEnvValue, setNewEnvValue] = useState("");
@@ -773,8 +784,16 @@ const HostDetailsPanel: React.FC<HostDetailsPanelPropsWithResize> = ({
     setActiveSubPanel("none");
   };
 
+  const displayHostChainIds = useMemo(
+    () => form.hostChain !== undefined
+      ? (form.hostChain.hostIds || [])
+      : (effectiveAuthHost.hostChain?.hostIds || []),
+    [effectiveAuthHost.hostChain?.hostIds, form.hostChain],
+  );
+  const hostChainInherited = form.hostChain === undefined && displayHostChainIds.length > 0;
+
   const availableHostsForChain = useMemo(() => {
-    const chainedIds = new Set(form.hostChain?.hostIds || []);
+    const chainedIds = new Set(displayHostChainIds);
     // Chain hops are SSH ProxyJump hops; never offer local/serial/telnet/plugin
     // entries (e.g. saved local shells) as jump hosts.
     return allHosts.filter((h) =>
@@ -782,14 +801,13 @@ const HostDetailsPanel: React.FC<HostDetailsPanelPropsWithResize> = ({
       && !chainedIds.has(h.id)
       && canServeAsSshJumpHost(h),
     );
-  }, [allHosts, form.id, form.hostChain?.hostIds]);
+  }, [allHosts, displayHostChainIds, form.id]);
 
   const chainedHosts = useMemo(() => {
-    const ids = form.hostChain?.hostIds || [];
-    return ids
+    return displayHostChainIds
       .map((id) => allHosts.find((h) => h.id === id))
       .filter(Boolean) as Host[];
-  }, [allHosts, form.hostChain?.hostIds]);
+  }, [allHosts, displayHostChainIds]);
 
   const groupOptions: ComboboxOption[] = useMemo(() => {
     return groups.map((g) => ({
@@ -905,11 +923,12 @@ const HostDetailsPanel: React.FC<HostDetailsPanelPropsWithResize> = ({
   if (activeSubPanel === "proxy") {
     return (
       <ProxyPanel
-        proxyConfig={form.proxyConfig}
+        proxyConfig={displayProxyConfig}
         proxyProfiles={proxyProfiles}
         identities={identities}
-        selectedProxyProfileId={form.proxyProfileId}
+        selectedProxyProfileId={displayProxyProfileId}
         directProxy={form.directProxy}
+        allowClear={hasHostProxyOverride}
         onUpdateProxy={updateProxyConfig}
         onSelectProxyProfile={selectProxyProfile}
         onSelectDirectProxy={selectDirectProxy}
@@ -1237,11 +1256,13 @@ const HostDetailsPanel: React.FC<HostDetailsPanelPropsWithResize> = ({
           showAlgorithmOverrides={showAlgorithmOverrides}
           setShowAlgorithmOverrides={setShowAlgorithmOverrides}
           chainedHosts={chainedHosts}
+          hostChainInherited={hostChainInherited}
           setActiveSubPanel={setActiveSubPanel}
           clearHostChain={clearHostChain}
           proxySummaryType={proxySummaryType}
           proxySummaryLabel={proxySummaryLabel}
           proxySummaryTooltip={proxySummaryTooltip}
+          proxyInherited={proxyInherited}
           clearProxyConfig={clearProxyConfig}
         />
 

components/QuickConnectWizard.interaction.test.tsx

@@ -0,0 +1,229 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { JSDOM } from "jsdom";
+import type { Identity, Host } from "../types";
+
+async function withWizard(
+  run: (fixture: Awaited<ReturnType<typeof mountWizard>>) => Promise<void>,
+  identities: Identity[] = [],
+) {
+  const fixture = await mountWizard(identities);
+  try {
+    await run(fixture);
+  } finally {
+    await fixture.cleanup();
+  }
+}
+
+async function mountWizard(identities: Identity[]) {
+  const dom = new JSDOM('<!doctype html><html><body><div id="root"></div></body></html>', {
+    url: "http://localhost", pretendToBeVisual: true,
+  });
+  const previous = new Map<string, PropertyDescriptor | undefined>();
+  const install = (key: string, value: unknown) => {
+    previous.set(key, Object.getOwnPropertyDescriptor(globalThis, key));
+    Object.defineProperty(globalThis, key, { configurable: true, writable: true, value });
+  };
+  for (const key of ["window", "document", "navigator", "HTMLElement", "HTMLInputElement", "Element", "Node", "MutationObserver", "Event", "CustomEvent", "MouseEvent", "KeyboardEvent", "FocusEvent"] as const) {
+    install(key, key === "window" ? dom.window : dom.window[key]);
+  }
+  install("getComputedStyle", dom.window.getComputedStyle.bind(dom.window));
+  install("requestAnimationFrame", dom.window.requestAnimationFrame.bind(dom.window));
+  install("cancelAnimationFrame", dom.window.cancelAnimationFrame.bind(dom.window));
+  install("IS_REACT_ACT_ENVIRONMENT", true);
+  const { act, useState } = await import("react");
+  const { createRoot } = await import("react-dom/client");
+  const { I18nProvider } = await import("../application/i18n/I18nProvider");
+  const { default: QuickConnectWizard } = await import("./QuickConnectWizard");
+  const target = { hostname: "example.com" };
+  const connected: Host[] = [];
+  const saved: Host[] = [];
+  let closeCount = 0;
+  function Fixture() {
+    const [open, setOpen] = useState(true);
+    return (
+      <I18nProvider locale="en">
+        {open && <QuickConnectWizard
+          open target={target} keys={[]} identities={identities}
+          onConnect={(host) => connected.push(host)}
+          onSaveHost={(host) => saved.push(host)}
+          onClose={() => { closeCount++; setOpen(false); }}
+        />}
+      </I18nProvider>
+    );
+  }
+  const root = createRoot(document.getElementById("root")!);
+  await act(async () => { root.render(<Fixture />); });
+  const button = (name: string) => {
+    const element = [...document.querySelectorAll<HTMLButtonElement>("button")]
+      .find((candidate) => candidate.getAttribute("aria-label") === name || candidate.textContent?.trim() === name);
+    assert.ok(element, `Button ${name} is present`);
+    return element;
+  };
+  const input = (selector: string) => {
+    const element = document.querySelector<HTMLInputElement>(selector);
+    assert.ok(element, `Input ${selector} is present`);
+    return element;
+  };
+  const overlay = () => {
+    const element = document.querySelector<HTMLElement>(".fixed.inset-0");
+    assert.ok(element, "Quick Connect is still open");
+    return element;
+  };
+  const click = async (element: HTMLElement) => {
+    await act(async () => { element.click(); });
+  };
+  const type = async (selector: string, value: string) => {
+    await act(async () => {
+      const element = input(selector);
+      Object.getOwnPropertyDescriptor(dom.window.HTMLInputElement.prototype, "value")!.set!.call(element, value);
+      element.dispatchEvent(new dom.window.Event("input", { bubbles: true }));
+    });
+    assert.equal(input(selector).value, value);
+  };
+  const key = async (element: HTMLElement, key: string) => {
+    await act(async () => { element.dispatchEvent(new dom.window.KeyboardEvent("keydown", { key, bubbles: true })); });
+  };
+  const settle = async () => { await act(async () => { await new Promise((resolve) => setTimeout(resolve, 50)); }); };
+  const outsideClick = async () => {
+    await act(async () => {
+      overlay().dispatchEvent(new dom.window.MouseEvent("mousedown", { bubbles: true }));
+      overlay().click();
+    });
+    assert.equal(closeCount, 0, "Background clicks must not close Quick Connect");
+    overlay();
+  };
+  return {
+    button, input, overlay, click, type, key, settle, outsideClick, connected, saved,
+    closeCount: () => closeCount,
+    async cleanup() {
+      await act(async () => { root.unmount(); });
+      dom.window.close();
+      for (const [key, descriptor] of previous) {
+        if (descriptor) Object.defineProperty(globalThis, key, descriptor);
+        else Reflect.deleteProperty(globalThis, key);
+      }
+    },
+  };
+}
+
+test("background clicks preserve each Quick Connect step and typed connection details", async () => {
+  await withWizard(async (f) => {
+    await f.type('input[type="number"]', "2222");
+    await f.outsideClick();
+    assert.equal(f.input('input[type="number"]').value, "2222");
+    await f.click(f.button("Continue"));
+    await f.type("#quick-username", "alice");
+    await f.outsideClick();
+    assert.equal(f.input("#quick-username").value, "alice");
+    await f.click(f.button("Continue"));
+    await f.type("#quick-password", "partly configured password");
+    await f.outsideClick();
+    await f.key(f.input("#quick-password"), "Escape");
+    assert.equal(f.closeCount(), 0);
+    assert.equal(f.input("#quick-password").value, "partly configured password");
+    await f.click(f.button("Back"));
+    assert.equal(f.input("#quick-username").value, "alice");
+    await f.click(f.button("Back"));
+    assert.equal(f.input('input[type="number"]').value, "2222");
+    await f.click(f.button("Continue"));
+    await f.click(f.button("Continue"));
+    assert.equal(f.input("#quick-password").value, "partly configured password");
+    await f.click(f.button("Continue"));
+    assert.equal(f.connected.length, 1);
+    assert.equal(f.connected[0].username, "alice");
+    assert.equal(f.connected[0].port, 2222);
+    assert.equal(f.connected[0].password, "partly configured password");
+    assert.equal(f.closeCount(), 1);
+    assert.equal(document.querySelector("h2"), null);
+  });
+});
+
+test("the portaled credential picker retains the wizard and selected identity", async () => {
+  await withWizard(async (f) => {
+    await f.type('input[type="number"]', "2222");
+    await f.click(f.input('[role="combobox"]'));
+    await f.settle();
+    const option = document.querySelector<HTMLElement>('[role="option"]');
+    assert.ok(option);
+    assert.equal(f.overlay().contains(option), false, "Options are portaled outside the wizard DOM");
+    await f.click(option);
+    assert.equal(f.closeCount(), 0);
+    assert.equal(f.input('[role="combobox"]').value, "Production identity");
+    assert.equal(f.input('input[type="number"]').value, "2222");
+    await f.outsideClick();
+    await f.click(f.button("Connect with preset"));
+    assert.equal(f.connected.length, 1);
+    assert.equal(f.connected[0].identityId, "identity-alice");
+    assert.equal(f.connected[0].username, "alice");
+    assert.equal(f.connected[0].port, 2222);
+    assert.equal(f.closeCount(), 1);
+  }, [{ id: "identity-alice", label: "Production identity", username: "alice", authMethod: "password", password: "preset secret", created: 1 }]);
+});
+
+test("the portaled save menu preserves credentials until explicit save and connect", async () => {
+  await withWizard(async (f) => {
+    await f.click(f.button("Continue"));
+    await f.type("#quick-username", "alice");
+    await f.key(f.input("#quick-username"), "Enter");
+    await f.type("#quick-password", "secret");
+    const trigger = f.button("Continue & Save");
+    await f.click(trigger);
+    await f.settle();
+    const menuItem = [...document.querySelectorAll<HTMLButtonElement>("button")]
+      .find((candidate) => candidate.textContent === "Continue & Save");
+    assert.ok(menuItem);
+    assert.equal(f.overlay().contains(menuItem), false, "Save menu is portaled outside the wizard DOM");
+    await f.click(menuItem.parentElement!);
+    assert.equal(f.closeCount(), 0);
+    assert.equal(f.input("#quick-password").value, "secret");
+    await f.key(document.body, "Escape");
+    assert.equal(trigger.getAttribute("aria-expanded"), "false");
+    assert.equal(f.closeCount(), 0);
+    await f.click(trigger);
+    await f.settle();
+    await f.outsideClick();
+    assert.equal(trigger.getAttribute("aria-expanded"), "false");
+    assert.equal(f.input("#quick-password").value, "secret");
+    await f.click(trigger);
+    await f.settle();
+    const save = [...document.querySelectorAll<HTMLButtonElement>("button")]
+      .find((candidate) => candidate.textContent === "Continue & Save");
+    assert.ok(save);
+    await f.click(save);
+    assert.equal(f.saved.length, 1);
+    assert.equal(f.connected.length, 1);
+    assert.equal(f.saved[0], f.connected[0]);
+    assert.equal(f.connected[0].username, "alice");
+    assert.equal(f.connected[0].password, "secret");
+    assert.equal(f.closeCount(), 1);
+  });
+});
+
+test("explicit Close dismisses the protocol step", async () => {
+  await withWizard(async (f) => {
+    await f.click(f.button("Close"));
+    assert.equal(f.closeCount(), 1);
+    assert.equal(document.querySelector("h2"), null);
+    assert.equal(f.connected.length, 0);
+  });
+});
+
+for (const step of ["username", "auth"]) {
+  test(`the header X explicitly closes the ${step} step`, async () => {
+    await withWizard(async (f) => {
+      await f.click(f.button("Continue"));
+      await f.type("#quick-username", "alice");
+      if (step === "auth") {
+        await f.click(f.button("Continue"));
+        await f.type("#quick-password", "secret");
+      }
+      const close = f.button("Close");
+      assert.ok(close.querySelector("svg.lucide-x"), "A visible X is provided on steps with Back");
+      await f.click(close);
+      assert.equal(f.closeCount(), 1);
+      assert.equal(document.querySelector("h2"), null);
+      assert.equal(f.connected.length, 0);
+    });
+  });
+}

components/QuickConnectWizard.tsx

@@ -8,6 +8,7 @@ import {
   Plug,
   Plus,
   User,
+  X,
 } from "lucide-react";
 import React, { useMemo, useState } from "react";
 import { createPortal } from "react-dom";
@@ -675,7 +676,6 @@ const QuickConnectWizard: React.FC<QuickConnectWizardProps> = ({
   const wizard = (
     <div
       className="fixed inset-0 z-50 flex items-center justify-center"
-      onClick={onClose}
     >
       <div
         className="w-[560px] max-w-[90vw] bg-background border border-border rounded-2xl animate-in fade-in-0 zoom-in-95 duration-200"
@@ -686,7 +686,7 @@ const QuickConnectWizard: React.FC<QuickConnectWizardProps> = ({
         onClick={(e) => e.stopPropagation()}
       >
         {/* Header */}
-        <div className="px-6 py-4 border-b border-border/50">
+        <div className="px-6 py-4 border-b border-border/50 flex items-center justify-between gap-4">
           <div className="flex items-center gap-2 min-w-0">
             <Plug size={18} className="shrink-0 text-foreground" />
             <div className="min-w-0">
@@ -696,6 +696,17 @@ const QuickConnectWizard: React.FC<QuickConnectWizardProps> = ({
               ) : null}
             </div>
           </div>
+          {step !== "protocol" && (
+            <Button
+              variant="ghost"
+              size="icon"
+              className="h-8 w-8 shrink-0"
+              aria-label={t("common.close")}
+              onClick={onClose}
+            >
+              <X size={16} />
+            </Button>
+          )}
         </div>
 
 

components/SettingsPage.tsx

@@ -247,6 +247,8 @@ const SettingsAITabContainer: React.FC = () => {
                 setResponseIdleTimeout={aiState.setResponseIdleTimeout}
                 maxIterations={aiState.maxIterations}
                 setMaxIterations={aiState.setMaxIterations}
+                aiSessionMessageCap={aiState.aiSessionMessageCap}
+                setAiSessionMessageCap={aiState.setAiSessionMessageCap}
                 webSearchConfig={aiState.webSearchConfig}
                 setWebSearchConfig={aiState.setWebSearchConfig}
                 quickMessages={aiState.quickMessages}

components/SftpView.tsx

@@ -759,7 +759,7 @@ const SftpViewInner: React.FC<SftpViewProps> = ({
               data-section="pane-magnification-hint"
             >
               {t('terminal.paneMagnification.hint')}: {t('terminal.layer.sftp')}
-              {paneMagnificationShortcutLabel ? ` · ${paneMagnificationShortcutLabel} / Esc` : ' · Esc'}
+              {paneMagnificationShortcutLabel ? ` · ${paneMagnificationShortcutLabel}` : ''}
             </div>
           )}
         </div>

components/Terminal.tsx

@@ -1,3 +1,6 @@
+import { terminalCwdStore } from '../application/state/terminalCwdStore';
+import { useTerminalDirectorySession } from '../application/state/useTerminalDirectorySession';
+import { refreshObservedTerminalDirectory, scheduleObservedTerminalDirectoryRefresh } from '../application/state/terminalDirectoryRegistry';
 import { publishTerminalSelectionTarget } from "../infrastructure/plugins/terminalSelectionRegistry";
 import { usePluginTerminalSelection } from "../application/state/usePluginTerminalSelection";
 import { clearTerminalBroadcastUserInput, markTerminalBroadcastUserInput } from "./terminal/runtime/terminalPacedBroadcast";
@@ -1246,6 +1249,7 @@ const TerminalComponent: React.FC<TerminalProps> = ({
 
   const clearTerminalCwd = useCallback((options?: { persistRestoreMetadata?: boolean }) => {
     terminalCwdTracker.clearRendererCwd();
+    terminalCwdStore.setCwd(sessionId, null);
     knownCwdRef.current = undefined;
     if (options?.persistRestoreMetadata === false) return;
     onTerminalCwdChange?.(sessionId, null);
@@ -2590,6 +2594,7 @@ const TerminalComponent: React.FC<TerminalProps> = ({
   const cwdAwareOnCommandSubmitted = useCallback((
     ...args: Parameters<NonNullable<typeof onCommandSubmitted>>
   ) => {
+    scheduleObservedTerminalDirectoryRefresh(sessionId);
     if (!shouldPreserveTerminalCwdAcrossCommand(hostRestrictsExtraSshChannels(host))) {
       invalidateTerminalCwdAfterCommand(
         terminalCwdTracker,
@@ -2603,6 +2608,7 @@ const TerminalComponent: React.FC<TerminalProps> = ({
   }, [host, onCommandSubmitted, onTerminalCwdChange, sessionId, terminalCwdTracker]);
   const pluginAwareOnCommandCompleted = useCallback(() => {
     pluginTerminalLifecycle.onCommandCompleted();
+    refreshObservedTerminalDirectory(sessionId);
     void xtermRuntimeRef.current?.pluginProviderHost?.commandCompleted();
     // Hibernate wake builds its runtime from this callback. Same local
     // prompt-return refresh as useTerminalEffects (#1952).
@@ -2615,6 +2621,7 @@ const TerminalComponent: React.FC<TerminalProps> = ({
     cwd: string | null,
     meta?: TerminalCwdChangeMeta,
   ) => {
+    terminalCwdStore.setCwd(changedSessionId, cwd, meta?.source);
     pluginTerminalLifecycle.onCwdChanged(cwd);
     onTerminalCwdChange?.(changedSessionId, cwd, meta);
   }, [onTerminalCwdChange, pluginTerminalLifecycle]);
@@ -2630,6 +2637,13 @@ const TerminalComponent: React.FC<TerminalProps> = ({
     pluginAwareOnTerminalCwdChange(sessionId, normalizedCwd ?? null, meta);
     void refreshProviderOutputs('cwd-changed');
   }, [pluginAwareOnTerminalCwdChange, refreshProviderOutputs, sessionId, terminalCwdTracker]);
+  useTerminalDirectorySession({
+    sessionId, status, host, shellType,
+    getBackendId: () => sessionRef.current,
+    isReady: () => isTerminalReadyForCommandInjection(sessionId),
+    publish: cwd => pluginAwareOnRuntimeCwdChange(cwd, { source: 'backend-strict' }),
+  });
+
   const pluginAwareOnTerminalTitleChange = useCallback((changedSessionId: string, title: string | null) => {
     terminalTitleRef.current = title || undefined;
     pluginTerminalLifecycle.onTitleChanged(title);
@@ -2771,6 +2785,7 @@ const TerminalComponent: React.FC<TerminalProps> = ({
     onTerminalDataCapture: handleTerminalDataCaptureOnce,
     onTerminalOutput: (chunk: string, meta?: TerminalSessionDataMeta) => {
       observeTerminalInputPrompt(chunk, meta);
+      scheduleObservedTerminalDirectoryRefresh(sessionId);
       appendOutputTriggerOutputRef.current(chunk, meta);
       if (onTerminalOutput) {
         onTerminalOutput(sessionId, chunk);
@@ -3521,6 +3536,8 @@ const TerminalComponent: React.FC<TerminalProps> = ({
     options?: {
       broadcast?: boolean;
       multiLineRunMode?: Snippet["multiLineRunMode"];
+      /** Submit compose blocks through the shell's advertised paste support. */
+      preferBracketedPaste?: boolean;
       /** When false, skip term.focus() so multi-tab fan-out does not steal focus. */
       focus?: boolean;
       /** Force sensitive classification on the write (bypassed password fan-out, #3488). */
@@ -3569,7 +3586,11 @@ const TerminalComponent: React.FC<TerminalProps> = ({
     // Wrap in bracketed paste BEFORE appending \r so the Enter is sent
     // outside the paste markers — otherwise shells treat it as pasted text
     // instead of a submit action.
-    if (!lineDelayMs && isMultiLine && term.modes.bracketedPasteMode && !disableBracketedPasteRef.current) {
+    // Compose submits a command block, so keep it in the shell's input buffer
+    // even when clipboard bracketing is disabled. Otherwise a running command
+    // can consume the later lines as stdin (#4062). Still require shell support.
+    if (!lineDelayMs && isMultiLine && term.modes.bracketedPasteMode
+      && (options?.preferBracketedPaste || !disableBracketedPasteRef.current)) {
       data = wrapBracketedPaste(data);
     }
     if (!noAutoRun) data = `${data}\r`;