fix(terminal): withdraw unreleased archive command shortcut

Neutralize bash PS0 around agent PTY wrapper reads, then restore. Skipped Codex P2 on __NCMCP_PS0 collision as edge-case thrash.

Fixes #3485

.github/workflows/ai-automation.yml

@@ -1202,8 +1202,7 @@ jobs:
           persist-credentials: false
 
       - name: Freeze trusted helper
-        run: cp scripts/ai-automation.cjs "$RUNNER_TEMP/ai-automation.cjs"
-          chmod 0444 "$RUNNER_TEMP/ai-automation.cjs"
+        run: *freeze_ai_helper
 
       - name: Install Claude Code CLI
         run: |

application/AppHandlers.connect.test.ts

@@ -7,6 +7,7 @@ import {
   handleKeyboardInteractiveSubmitImpl,
   handleTrayPanelConnectRequestImpl,
 } from './app/AppHandlers.ts';
+import { resolveShellSetting } from '../lib/useDiscoveredShells.ts';
 import type { Host } from '../types';
 
 const baseHost: Host = {
@@ -398,3 +399,69 @@ test('keyboard-interactive submit keeps the prompt and password unchanged when d
   assert.equal(hosts[0].password, 'old-password');
   assert.deepEqual(errors, ['Request not found']);
 });
+
+test('local host without explicit shell resolves the configured Settings shell', () => {
+  const connectedHosts: Host[] = [];
+  const localHost: Host = { ...baseHost, id: 'local-1', hostname: 'localhost', protocol: 'local' };
+  const discoveredShells = [
+    { id: 'wsl-ubuntu', name: 'Ubuntu (WSL)', command: 'wsl.exe', args: ['-d', 'Ubuntu'] },
+  ];
+
+  handleConnectToHostImpl(
+    () => ({
+      addConnectionLog: () => {},
+      connectToHost: (host: Host) => {
+        connectedHosts.push(host);
+        return 'local-session';
+      },
+      discoveredShells,
+      identities: [],
+      keys: [],
+      resolveEffectiveHost: (host: Host) => host,
+      resolveHostAuth: () => ({ username: '' }),
+      resolveShellSetting,
+      systemInfoRef: { current: { username: 'local-user', hostname: 'local-host' } },
+      terminalSettings: { localShell: 'wsl-ubuntu' },
+    }) as never,
+    localHost,
+  );
+
+  assert.equal(connectedHosts.length, 1);
+  assert.equal(connectedHosts[0].localShell, 'wsl.exe');
+  assert.deepEqual(connectedHosts[0].localShellArgs, ['-d', 'Ubuntu']);
+  assert.equal(connectedHosts[0].localShellName, 'Ubuntu (WSL)');
+});
+
+test('local host with an explicit shell keeps it (no Settings fallback)', () => {
+  const connectedHosts: Host[] = [];
+  const localHost: Host = {
+    ...baseHost,
+    id: 'local-2',
+    hostname: 'localhost',
+    protocol: 'local',
+    localShell: 'pwsh',
+  };
+
+  handleConnectToHostImpl(
+    () => ({
+      addConnectionLog: () => {},
+      connectToHost: (host: Host) => {
+        connectedHosts.push(host);
+        return 'local-session-2';
+      },
+      discoveredShells: [],
+      identities: [],
+      keys: [],
+      resolveEffectiveHost: (host: Host) => host,
+      resolveHostAuth: () => ({ username: '' }),
+      resolveShellSetting,
+      systemInfoRef: { current: { username: 'local-user', hostname: 'local-host' } },
+      terminalSettings: { localShell: 'wsl-ubuntu' },
+    }) as never,
+    localHost,
+  );
+
+  assert.equal(connectedHosts.length, 1);
+  assert.equal(connectedHosts[0].localShell, 'pwsh');
+  assert.equal(connectedHosts[0].localShellName, undefined);
+});

application/app/AppHandlers.ts

@@ -4,6 +4,7 @@ import type { Host, HostProtocol, TerminalSession } from '../../types';
 import type { PassphraseRequest } from '../../components/PassphraseModal';
 import type { TerminalPopupPayload } from '../../domain/systemManager/types';
 import { getEffectiveHostDistro, classifyDistroId, hostRestrictsExtraSshChannels, shouldProbeSessionCwd } from '../../domain/host';
+import { resolveHostDefaultLocalShell } from '../../domain/localShellHost';
 import { getAvailablePaneMagnificationController } from '../../domain/paneMagnification';
 import { sanitizeHostIconFields } from '../../domain/hostIcon';
 import { resolveEffectiveTerminalProtocol } from '../../domain/terminalProtocol';
@@ -204,7 +205,10 @@ export function handleTrayPanelConnectImpl(getCtx: AppContextGetter, hostId: str
       hostId: host.id,
       hostLabel: host.label,
       hostname: host.hostname,
-      username: resolvedAuth.username || 'root',
+      // Local-shell vault hosts carry no SSH credentials, so log the system
+      // user like local terminals do (see handleConnectToHostImpl) instead of
+      // 'root' or an inherited group SSH username.
+      username: protocol === 'local' ? username : (resolvedAuth.username || 'root'),
       protocol,
       ...getLogHostVisualSnapshot(effectiveHost),
       startTime: Date.now(),
@@ -1104,11 +1108,15 @@ export function handleCreateLocalTerminalImpl(
 }
 
 export function handleConnectToHostImpl(getCtx: AppContextGetter, host: Host, hidden = false) {
-  const { addConnectionLog, connectToHost, identities, keys, resolveEffectiveHost, resolveHostAuth, systemInfoRef } = getCtx();
+  const { addConnectionLog, connectToHost, discoveredShells, identities, keys, resolveEffectiveHost, resolveHostAuth, resolveShellSetting, systemInfoRef, terminalSettings } = getCtx();
 {
     const { username, hostname: localHost } = systemInfoRef.current;
 
-    const effectiveHost = resolveEffectiveHost(host);
+    const effectiveHost = resolveHostDefaultLocalShell(resolveEffectiveHost(host), {
+      discoveredShells,
+      resolveShellSetting,
+      terminalSettings,
+    });
 
     // Handle serial hosts separately
     if (effectiveHost.protocol === 'serial') {
@@ -1138,7 +1146,10 @@ export function handleConnectToHostImpl(getCtx: AppContextGetter, host: Host, hi
       hostId: host.id,
       hostLabel: host.label,
       hostname: host.hostname,
-      username: resolvedAuth.username || 'root',
+      // Local-shell vault hosts carry no SSH credentials, so log the system
+      // user like local terminals do (see handleCreateLocalTerminalImpl)
+      // instead of 'root' or an inherited group SSH username.
+      username: protocol === 'local' ? username : (resolvedAuth.username || 'root'),
       protocol,
       ...getLogHostVisualSnapshot(effectiveHost),
       startTime: Date.now(),
@@ -1186,8 +1197,13 @@ export function hasMultipleProtocolsImpl(getCtx: AppContextGetter, host: Host) {
     // Gates the protocol picker (legacy name kept for its existing wiring).
     // Only prompt when Telnet is available but isn't the host's default protocol;
     // SSH-only, SSH+Mosh and Telnet-default all connect directly.
+    // SSH-only guard, matching VaultView's handleHostConnect: local-shell and
+    // serial hosts must always launch their own transport, never offer
+    // SSH/Telnet pickers driven by an inherited group Telnet flag. Hosts
+    // without an explicit protocol are legacy SSH entries.
     const effective = resolveEffectiveHost(host);
-    return Boolean(effective.telnetEnabled) && effective.protocol !== 'telnet';
+    const effectiveProtocol = effective.protocol ?? 'ssh';
+    return effectiveProtocol === 'ssh' && Boolean(effective.telnetEnabled);
   }
 }
 

application/app/AppHostEditorLayer.test.ts

@@ -34,6 +34,17 @@ test('serial targets use the serial editor', () => {
   );
 });
 
+test('local targets use the local shell editor', () => {
+  assert.equal(
+    resolveWorkSurfaceHostEditorKind({
+      mode: 'edit',
+      openedHost: host({ protocol: 'local' }),
+      requestId: 3,
+    }),
+    'local',
+  );
+});
+
 test('new and ssh targets use the standard editor', () => {
   assert.equal(
     resolveWorkSurfaceHostEditorKind({ mode: 'new', defaultGroup: null, requestId: 1 }),
@@ -71,8 +82,8 @@ test('editor overlay leaves the work surface interactive outside the panel', ()
 
   assert.match(source, /pointer-events-none absolute inset-0 z-40/);
   assert.match(source, /\[&>\*\]:pointer-events-auto/);
-  assert.equal((source.match(/className="pointer-events-auto"/g) ?? []).length, 2);
-  assert.equal((source.match(/layout="overlay"/g) ?? []).length, 2);
+  assert.equal((source.match(/className="pointer-events-auto"/g) ?? []).length, 3);
+  assert.equal((source.match(/layout="overlay"/g) ?? []).length, 3);
 });
 
 test('editor host panels share vault resize width persistence', () => {
@@ -81,7 +92,7 @@ test('editor host panels share vault resize width persistence', () => {
   assert.match(source, /STORAGE_KEY_VAULT_HOST_PANEL_WIDTH/);
   assert.match(source, /resizable:\s*true/);
   assert.match(source, /\{\.\.\.hostPanelResizeProps\}/);
-  assert.equal((source.match(/\{\.\.\.hostPanelResizeProps\}/g) ?? []).length, 2);
+  assert.equal((source.match(/\{\.\.\.hostPanelResizeProps\}/g) ?? []).length, 3);
 });
 
 test('editor stays mounted while another app surface is active', () => {

application/app/AppHostEditorLayer.tsx

@@ -5,6 +5,7 @@ import type { EditorTabChrome } from '../state/editorTabStore';
 import type { LogView } from '../state/logViewState';
 import { useI18n } from '../i18n/I18nProvider';
 import HostDetailsPanel from '../../components/HostDetailsPanel';
+import LocalShellHostDetailsPanel from '../../components/LocalShellHostDetailsPanel';
 import SerialHostDetailsPanel from '../../components/SerialHostDetailsPanel';
 import { PortalContainerProvider } from '../../components/ui/portal-container';
 import { resolveGroupDefaults } from '../../domain/groupConfig';
@@ -22,14 +23,16 @@ import type {
 } from '../../types';
 import { useWorkSurfaceVisible } from './AppHostEditorSurface';
 
-export type WorkSurfaceHostEditorKind = 'standard' | 'serial';
+export type WorkSurfaceHostEditorKind = 'standard' | 'serial' | 'local';
 
 export function resolveWorkSurfaceHostEditorKind(
   target: WorkSurfaceHostEditorTarget,
 ): WorkSurfaceHostEditorKind {
   return target.mode === 'edit' && target.openedHost.protocol === 'serial'
     ? 'serial'
-    : 'standard';
+    : target.mode === 'edit' && target.openedHost.protocol === 'local'
+      ? 'local'
+      : 'standard';
 }
 
 function addGroupAndAncestors(groups: Set<string>, path: string | null | undefined) {
@@ -160,7 +163,18 @@ export const AppHostEditorLayer: React.FC<AppHostEditorLayerProps> = ({
       style={getAppHostEditorLayerStyle(surfaceVisible)}
     >
       <PortalContainerProvider container={portalContainer}>
-        {target.mode === 'edit' && target.openedHost.protocol === 'serial' ? (
+        {target.mode === 'edit' && target.openedHost.protocol === 'local' ? (
+          <LocalShellHostDetailsPanel
+            key={editorKey}
+            initialData={target.openedHost}
+            groups={groups}
+            onSave={onSave}
+            onCancel={onCancel}
+            layout="overlay"
+            className="pointer-events-auto"
+            {...hostPanelResizeProps}
+          />
+        ) : target.mode === 'edit' && target.openedHost.protocol === 'serial' ? (
           <SerialHostDetailsPanel
             key={editorKey}
             initialData={target.openedHost}

application/app/AppSideEffects.localShell.test.ts

@@ -0,0 +1,35 @@
+import assert from 'node:assert/strict';
+import { readFileSync } from 'node:fs';
+import test from 'node:test';
+import ts from 'typescript';
+import { createLocalShellHost, resolveHostDefaultLocalShell } from '../../domain/localShellHost';
+import { createHostTerminalSession } from '../state/sessionFactories';
+
+// Exercise the production application callback, including its async command
+// resolution boundary, before the state hook snapshots the shell type.
+const source = readFileSync(new URL('./AppSideEffects.tsx', import.meta.url), 'utf8');
+const callback = source.match(/const handleRunSnippet = useCallback\(([\s\S]*?)\n {2}\);/)?.[1];
+assert.ok(callback);
+const compiled = ts.transpile(`const run = useCallback(${callback});`, { target: ts.ScriptTarget.ES2022 });
+
+for (const script of [false, true]) {
+  test(`saved default local shell is resolved before ${script ? 'script' : 'snippet'} sessions are created`, async () => {
+    let session: ReturnType<typeof createHostTerminalSession> | undefined;
+    const run = new Function('useCallback', 'isScriptSnippet', 'runSnippet', 'resolveSnippetCommand', 'resolveEffectiveHost', `${compiled} return run;`)(
+      (value: unknown) => value,
+      () => script,
+      (_snippet: unknown, hosts: ReturnType<typeof createLocalShellHost>[]) => {
+        session = createHostTerminalSession('snippet-local', hosts[0]);
+      },
+      async () => 'echo hello',
+      (host: ReturnType<typeof createLocalShellHost>) => resolveHostDefaultLocalShell(host, {
+        terminalSettings: { localShell: 'cmd' },
+        resolveShellSetting: () => ({ command: 'cmd.exe' }),
+      }),
+    );
+    await run({ id: 'snippet-1' }, [createLocalShellHost({ os: 'windows' })]);
+    assert.equal(session?.protocol, 'local');
+    assert.equal(session?.localShell, 'cmd.exe');
+    assert.equal(session?.shellType, 'cmd');
+  });
+}

application/app/AppSideEffects.tsx

@@ -38,6 +38,7 @@ import {
 import { isTerminalBootEpochCurrent } from '../../domain/terminalBootEpoch';
 import { useI18n } from '../i18n/I18nProvider';
 import { matchesKeyBinding } from '../../domain/models';
+import { resolveHostDefaultLocalShell } from '../../domain/localShellHost';
 import { resolveGroupDefaults, applyGroupDefaults } from '../../domain/groupConfig';
 import { upsertKnownHost } from '../../domain/knownHosts';
 import { materializeHostProxyProfile } from '../../domain/proxyProfiles';
@@ -53,6 +54,7 @@ import {
 } from '../../domain/terminalAppearance';
 import { selectConnectionLogForTerminalDataCapture } from '../../domain/connectionLog';
 import { collectSessionIds } from '../../domain/workspace';
+import { useHostOpenSessionReuse } from '../state/useHostOpenSessionReuse';
 import type { PaneMagnificationController } from '../../domain/paneMagnification';
 import { resolveCloseIntent } from '../state/resolveCloseIntent';
 import { resolveSnippetsShortcutIntent } from '../state/resolveSnippetsShortcutIntent';
@@ -269,22 +271,6 @@ export function AppSideEffects() {
     renameSessionInline,
   } = sessionState;
 
-  // Presentation-field thrash stays off Host bags (Hosts use retainStable);
-  // AppSideEffects only needs host/session maps for glue handlers and effects.
-  const handleRunSnippet = useCallback(
-    async (snippet: Snippet, targetHosts: Host[]) => {
-      if (targetHosts.length === 0) return;
-      if (isScriptSnippet(snippet)) {
-        runSnippet(snippet, targetHosts);
-        return;
-      }
-      const command = await resolveSnippetCommand(snippet);
-      if (command === null) return;
-      runSnippet(snippet, targetHosts, command);
-    },
-    [runSnippet],
-  );
-
   // Presence-only list: keystrokes must not rebuild App domains / TopTabs structure.
   const editorTabs = useEditorTabChromeList();
 
@@ -1366,8 +1352,32 @@ export function AppSideEffects() {
           { validProxyProfileIds: proxyProfileIdSet },
         )
       : applyGroupDefaults(host, {}, { validProxyProfileIds: proxyProfileIdSet });
-    return materializeHostProxyProfile(withGroupDefaults, proxyProfiles);
-  }, [groupConfigs, proxyProfileIdSet, proxyProfiles]);
+    const effectiveHost = materializeHostProxyProfile(withGroupDefaults, proxyProfiles);
+    // Local-shell vault hosts saved with "System default shell" carry no
+    // localShell; resolve the Settings → Terminal shell here at the shared
+    // effective-host boundary so every launch path (connect, tray/dock open,
+    // workspace creation/append, tunnels) uses the configured shell instead
+    // of silently falling back to the backend OS default shell.
+    return resolveHostDefaultLocalShell(effectiveHost, {
+      discoveredShells,
+      resolveShellSetting,
+      terminalSettings,
+    });
+  }, [groupConfigs, proxyProfileIdSet, proxyProfiles, discoveredShells, terminalSettings]);
+
+  const handleRunSnippet = useCallback(
+    async (snippet: Snippet, targetHosts: Host[]) => {
+      if (targetHosts.length === 0) return;
+      if (isScriptSnippet(snippet)) {
+        runSnippet(snippet, targetHosts.map(resolveEffectiveHost));
+        return;
+      }
+      const command = await resolveSnippetCommand(snippet);
+      if (command === null) return;
+      runSnippet(snippet, targetHosts.map(resolveEffectiveHost), command);
+    },
+    [runSnippet, resolveEffectiveHost],
+  );
 
   const createWorkspaceWithEffectiveHosts = useCallback((name: string, selectedHosts: Host[]) => {
     createWorkspaceWithHosts(name, selectedHosts.map(resolveEffectiveHost));
@@ -1398,14 +1408,17 @@ export function AppSideEffects() {
     return handleConnectToHostImpl(() => ({
       addConnectionLog,
       connectToHost,
+      discoveredShells,
       host,
       identities,
       keys,
       resolveEffectiveHost: effectiveHostResolver,
       resolveHostAuth,
+      resolveShellSetting,
       systemInfoRef,
+      terminalSettings,
     }), host, hidden);
-  }, [addConnectionLog, connectToHost, resolveEffectiveHost, identities, keys]);
+  }, [addConnectionLog, connectToHost, resolveEffectiveHost, identities, keys, discoveredShells, terminalSettings]);
 
   const handleConnectToHostWithTabName = useCallback((host: Host, tabName?: string) => {
     const sessionId = handleConnectToHost(host);
@@ -1432,6 +1445,10 @@ export function AppSideEffects() {
     return { ok: true as const, sessionId, host };
   }, [handleConnectToHost]);
 
+  const findExistingSessionForHostForVaultAgent = useHostOpenSessionReuse({
+    sessions, hosts, keys, identities, resolveEffectiveHost,
+  });
+
   const closeSessionForVaultAgent = useCallback((sessionId: string) => {
     if (!sessions.some((session) => session.id === sessionId)) {
       return { ok: false as const, error: `Session "${sessionId}" was not found.` };
@@ -1474,6 +1491,7 @@ export function AppSideEffects() {
     stopTunnel,
     stopRuleTunnels,
     openHost: openHostForVaultAgent,
+    findExistingSessionForHost: findExistingSessionForHostForVaultAgent,
     closeSession: closeSessionForVaultAgent,
     getScriptSessionMeta: (sessionId) => sessions.find((session) => session.id === sessionId),
   });

application/app/AppView.tsx

@@ -37,6 +37,7 @@ import { useExternalMcpToggleState } from '../state/useExternalMcpToggleState';
 import { selectPluginThemeTokens } from '../state/pluginContributionEnvironment';
 import { netcattyBridge } from '../../infrastructure/services/netcattyBridge';
 import { resolveEffectiveTerminalHost } from '../../domain/terminalHostResolution';
+import { useDefaultLocalShellContext } from '../../lib/useDiscoveredShells';
 import { getAvailablePaneMagnificationController } from '../../domain/paneMagnification';
 import { pluginViewTabStore, usePluginViewTabs } from '../state/pluginViewTabStore';
 import { buildPluginSettingScopeCatalog } from '../state/usePluginSettingScopeCatalog';
@@ -354,14 +355,16 @@ function AppViewInner({ domains }: AppViewProps) {
     [proxyProfiles],
   );
 
+  const defaultLocalShell = useDefaultLocalShellContext(terminalSettings);
   const resolveWorkspaceAppendHost = useCallback((host: typeof hosts[number]) => (
     resolveEffectiveTerminalHost({
       host,
       groupConfigs,
       proxyProfiles,
       validProxyProfileIds,
+      defaultLocalShell,
     })
-  ), [groupConfigs, proxyProfiles, validProxyProfileIds]);
+  ), [groupConfigs, proxyProfiles, validProxyProfileIds, defaultLocalShell]);
 
   const handleAppendHostToWorkspace = useCallback((workspaceId: string, hostId: string) => {
     const host = hosts.find((entry) => entry.id === hostId);

application/i18n/locales/en/ai.ts

@@ -522,13 +522,21 @@ export const enAiMessages: Messages = {
   'ai.chat.hoursAgo': '{n}h ago',
   'ai.chat.daysAgo': '{n}d ago',
   'ai.chat.newChat': 'New Chat',
+  'ai.chat.undoLastTurn': 'Undo last turn',
+  'ai.chat.undoLastTurnNotice': "Original chat kept. Commands and file changes are not undone. Return to the original chat for saved full outputs and existing background tasks.",
   'ai.chat.allSessions': 'All Sessions',
   'ai.chat.loadEarlierMessages': 'Load earlier messages ({n} more)',
   'ai.chat.jumpNav': 'Jump to message',
   'ai.chat.jumpUntitled': '(empty message)',
   'ai.chat.usedTools': 'Tools used: {n}',
   'ai.chat.loadMoreSessions': 'Load more sessions ({n} more)',
+  'ai.chat.searchSessions': 'Search titles and recent content…',
+  'ai.chat.clearSessionSearch': 'Clear session search',
+  'ai.chat.searchSessionsHint': 'Searches titles, prioritizing newer messages and entries. For long messages and tool outputs, only a limited portion at the beginning is searched. This is not full-text search.',
+  'ai.chat.noMatchingSessions': 'No matches in titles or recent retained content',
   'ai.chat.noSessions': 'No previous sessions',
+  'ai.chat.forkFromHere': 'Fork from here',
+  'ai.chat.forkCreated': 'Branched into a new chat — the original stays in history.',
   'ai.chat.retryHint': 'You can retry by sending your message again.',
   'ai.chat.approvalTimeout': 'Tool approval timed out after 5 minutes. You can retry by sending your message again.',
   'ai.chat.menuHosts': 'Hosts',

application/i18n/locales/en/core.ts

@@ -1123,6 +1123,7 @@ Highlight the focused split pane:
   'vault.tree.expandAll': 'Expand All',
   'vault.tree.collapseAll': 'Collapse All',
   'vault.hosts.newHost': 'New Host',
+  'vault.hosts.newLocalShell': 'Local Shell (CMD)',
   'vault.hosts.newGroup': 'New Group',
   'vault.hosts.import': 'Import',
   'vault.hosts.export': 'Export',
@@ -1148,6 +1149,9 @@ Highlight the focused split pane:
   'vault.hosts.deleteMultiple.success': 'Deleted {count} hosts',
   'vault.hosts.connectSelected': 'Connect ({count})',
   'vault.hosts.connectMultiple.success': 'Connecting {count} hosts',
+  'vault.hosts.moveSelected': 'Move to group ({count})',
+  'vault.hosts.moveSelected.description': 'Move the selected hosts to an existing group, or leave them ungrouped. Selected groups are not moved.',
+  'vault.hosts.moveMultiple.success': 'Moved {count} hosts to {group}',
   'vault.hosts.moveToGroup.success': 'Moved {host} to {group}',
   'vault.hosts.errors.nameRequired': 'Host name is required.',
   'vault.hosts.empty.title': 'Set up your hosts',

application/i18n/locales/en/vault.ts

@@ -1018,6 +1018,21 @@ export const enVaultMessages: Messages = {
   'hostDetails.addTag': 'Add a tag...',
   'hostDetails.createTag': 'Create tag',
   'hostDetails.createGroup': 'Create group',
+  // Local shell (CMD) host entries
+  'localShell.subtitle': 'Local Shell',
+  'localShell.panel.title': 'New Local Shell',
+  'localShell.panel.title.edit': 'Edit Local Shell',
+  'localShell.field.label': 'Name',
+  'localShell.field.labelPlaceholder': 'e.g. Project A · CMD',
+  'localShell.field.shell': 'Shell',
+  'localShell.field.shellDefault': 'System default shell',
+  'localShell.field.shellDefaultDesc': 'Leave empty to use the default local shell configured in Settings → Terminal.',
+  'localShell.field.shellEmpty': 'No shells found',
+  'localShell.field.shellResolved': 'Runs {command}',
+  'localShell.field.startDir': 'Start directory',
+  'localShell.field.startDirPlaceholder': 'Inherit global start directory (home if unset)',
+  'localShell.saveAndConnect': 'Save & Connect',
+
   'hostDetails.plugin.title': 'Plugin connection',
   'hostDetails.plugin.provider.placeholder': 'Select a connection provider',
   'hostDetails.plugin.provider.empty': 'No connection providers are installed',

application/i18n/locales/es/ai.ts

@@ -513,13 +513,21 @@ export const esAiMessages: Messages = {
   'ai.chat.hoursAgo': 'hace {n} h',
   'ai.chat.daysAgo': 'hace {n} d',
   'ai.chat.newChat': 'Nuevo chat',
+  'ai.chat.undoLastTurn': 'Deshacer el último turno',
+  'ai.chat.undoLastTurnNotice': "Se conserva el chat original. Los comandos y cambios de archivos no se deshacen. Consulta allí las salidas completas guardadas y las tareas en segundo plano existentes.",
   'ai.chat.allSessions': 'Todas las sesiones',
   'ai.chat.loadEarlierMessages': 'Cargar mensajes anteriores ({n} más)',
   'ai.chat.jumpNav': 'Ir al mensaje',
   'ai.chat.jumpUntitled': '(mensaje vacío)',
   'ai.chat.usedTools': 'Herramientas usadas: {n}',
   'ai.chat.loadMoreSessions': 'Cargar más sesiones ({n} más)',
+  'ai.chat.searchSessions': 'Buscar títulos y contenido reciente…',
+  'ai.chat.clearSessionSearch': 'Borrar la búsqueda de sesiones',
+  'ai.chat.searchSessionsHint': 'Busca en los títulos y da prioridad a los mensajes y entradas más recientes. De los mensajes largos y las salidas de herramientas, solo se busca una parte limitada del comienzo. No es una búsqueda de texto completo.',
+  'ai.chat.noMatchingSessions': 'Sin coincidencias en títulos ni contenido reciente conservado',
   'ai.chat.noSessions': 'No hay sesiones anteriores',
+  'ai.chat.forkFromHere': 'Bifurcar desde aquí',
+  'ai.chat.forkCreated': 'Conversación bifurcada en un chat nuevo; el original permanece en el historial.',
   'ai.chat.retryHint': 'Puedes reintentar enviando tu mensaje de nuevo.',
   'ai.chat.approvalTimeout': 'La aprobación de la herramienta expiró después de 5 minutos. Puedes reintentar enviando tu mensaje de nuevo.',
   'ai.chat.menuHosts': 'Hosts',

application/i18n/locales/es/core.ts

@@ -1081,6 +1081,7 @@ Resalta el panel dividido enfocado:
   'vault.tree.expandAll': 'Expandir todo',
   'vault.tree.collapseAll': 'Contraer todo',
   'vault.hosts.newHost': 'Nuevo host',
+  'vault.hosts.newLocalShell': 'Shell local (CMD)',
   'vault.hosts.newGroup': 'Nuevo grupo',
   'vault.hosts.import': 'Importar',
   'vault.hosts.export': 'Exportar',
@@ -1106,6 +1107,9 @@ Resalta el panel dividido enfocado:
   'vault.hosts.deleteMultiple.success': 'Se eliminaron {count} hosts',
   'vault.hosts.connectSelected': 'Conectar ({count})',
   'vault.hosts.connectMultiple.success': 'Conectando {count} hosts',
+  'vault.hosts.moveSelected': 'Mover al grupo ({count})',
+  'vault.hosts.moveSelected.description': 'Mueve los hosts seleccionados a un grupo existente o los deja sin grupo. Los grupos seleccionados no se mueven.',
+  'vault.hosts.moveMultiple.success': 'Se movieron {count} hosts a {group}',
   'vault.hosts.moveToGroup.success': 'Se movió {host} a {group}',
   'vault.hosts.errors.nameRequired': 'Se requiere el nombre del host.',
   'vault.hosts.empty.title': 'Configura tus hosts',

application/i18n/locales/es/vault.ts

@@ -1008,6 +1008,21 @@ export const esVaultMessages: Messages = {
   'hostDetails.addTag': 'Agregar una etiqueta...',
   'hostDetails.createTag': 'Crear etiqueta',
   'hostDetails.createGroup': 'Crear grupo',
+  // Entradas de shell local (CMD) en la bóveda
+  'localShell.subtitle': 'Shell local',
+  'localShell.panel.title': 'Nueva shell local',
+  'localShell.panel.title.edit': 'Editar shell local',
+  'localShell.field.label': 'Nombre',
+  'localShell.field.labelPlaceholder': 'p. ej. Proyecto A · CMD',
+  'localShell.field.shell': 'Shell',
+  'localShell.field.shellDefault': 'Shell predeterminada del sistema',
+  'localShell.field.shellDefaultDesc': 'Si se deja vacío, se usa la shell local predeterminada configurada en Ajustes → Terminal.',
+  'localShell.field.shellEmpty': 'No se encontraron shells',
+  'localShell.field.shellResolved': 'Ejecuta {command}',
+  'localShell.field.startDir': 'Directorio de inicio',
+  'localShell.field.startDirPlaceholder': 'Heredar directorio inicial global (personal si no se configura)',
+  'localShell.saveAndConnect': 'Guardar y conectar',
+
   'hostDetails.plugin.title': 'Conexión de plugin',
   'hostDetails.plugin.provider.placeholder': 'Selecciona un proveedor de conexión',
   'hostDetails.plugin.provider.empty': 'No hay proveedores de conexión instalados',

application/i18n/locales/ru/ai.ts

@@ -469,13 +469,21 @@ export const ruAiMessages: Messages = {
   'ai.chat.hoursAgo': '{n}ч назад',
   'ai.chat.daysAgo': '{n}д назад',
   'ai.chat.newChat': 'Новый чат',
+  'ai.chat.undoLastTurn': 'Отменить последний ход',
+  'ai.chat.undoLastTurnNotice': "Исходный чат сохранён. Команды и изменения файлов не отменяются. Полные сохранённые результаты и фоновые задачи доступны в исходном чате.",
   'ai.chat.allSessions': 'Все сессии',
   'ai.chat.loadEarlierMessages': 'Загрузить более ранние сообщения (ещё {n})',
   'ai.chat.jumpNav': 'Перейти к сообщению',
   'ai.chat.jumpUntitled': '(пустое сообщение)',
   'ai.chat.usedTools': 'Использовано инструментов: {n}',
   'ai.chat.loadMoreSessions': 'Загрузить больше сессий (ещё {n})',
+  'ai.chat.searchSessions': 'Поиск по заголовкам и недавнему содержимому…',
+  'ai.chat.clearSessionSearch': 'Очистить поиск сессий',
+  'ai.chat.searchSessionsHint': 'Поиск по заголовкам с приоритетом более новых сообщений и записей. В длинных сообщениях и результатах инструментов поиск охватывает только ограниченную начальную часть. Это не полнотекстовый поиск.',
+  'ai.chat.noMatchingSessions': 'Нет совпадений в заголовках и недавнем сохранённом содержимом',
   'ai.chat.noSessions': 'Предыдущих сессий нет',
+  'ai.chat.forkFromHere': 'Ветвление отсюда',
+  'ai.chat.forkCreated': 'Разговор перенесён в новый чат; оригинал остаётся в истории.',
   'ai.chat.retryHint': 'Вы можете повторить попытку, отправив сообщение ещё раз.',
   'ai.chat.approvalTimeout': 'Время ожидания одобрения инструмента истекло через 5 минут. Вы можете повторить попытку, отправив сообщение ещё раз.',
   'ai.chat.menuHosts': 'Хосты',

application/i18n/locales/ru/vault.ts

@@ -102,6 +102,7 @@ export const ruVaultMessages: Messages = {
   'vault.tree.expandAll': 'Развернуть все',
   'vault.tree.collapseAll': 'Свернуть все',
   'vault.hosts.newHost': 'Новый хост',
+  'vault.hosts.newLocalShell': 'Локальная оболочка (CMD)',
   'vault.hosts.newGroup': 'Новая группа',
   'vault.hosts.import': 'Импорт',
   'vault.hosts.export': 'Экспорт',
@@ -127,6 +128,9 @@ export const ruVaultMessages: Messages = {
   'vault.hosts.deleteMultiple.success': 'Удалено хостов: {count}',
   'vault.hosts.connectSelected': 'Подключить ({count})',
   'vault.hosts.connectMultiple.success': 'Подключение хостов: {count}',
+  'vault.hosts.moveSelected': 'Переместить в группу ({count})',
+  'vault.hosts.moveSelected.description': 'Переместить выбранные хосты в существующую группу или оставить без группы. Выбранные группы не перемещаются.',
+  'vault.hosts.moveMultiple.success': 'Перемещено {count} хостов в {group}',
   'vault.hosts.moveToGroup.success': 'Хост {host} перемещён в {group}',
   'vault.hosts.empty.title': 'Настройте свои хосты',
   'vault.hosts.empty.desc': 'Сохраняйте хосты, чтобы быстро подключаться к серверам, виртуальным машинам и контейнерам.',
@@ -1051,6 +1055,21 @@ export const ruVaultMessages: Messages = {
   'hostDetails.addTag': 'Добавить тег...',
   'hostDetails.createTag': 'Создать тег',
   'hostDetails.createGroup': 'Создать группу',
+  // Записи локальной оболочки (CMD) в хранилище
+  'localShell.subtitle': 'Локальная оболочка',
+  'localShell.panel.title': 'Новая локальная оболочка',
+  'localShell.panel.title.edit': 'Изменить локальную оболочку',
+  'localShell.field.label': 'Название',
+  'localShell.field.labelPlaceholder': 'напр. Проект A · CMD',
+  'localShell.field.shell': 'Оболочка',
+  'localShell.field.shellDefault': 'Системная оболочка по умолчанию',
+  'localShell.field.shellDefaultDesc': 'Если оставить пустым, используется локальная оболочка по умолчанию из Настройки → Терминал.',
+  'localShell.field.shellEmpty': 'Оболочки не найдены',
+  'localShell.field.shellResolved': 'Запускает {command}',
+  'localShell.field.startDir': 'Начальный каталог',
+  'localShell.field.startDirPlaceholder': 'Использовать общий начальный каталог (иначе домашний)',
+  'localShell.saveAndConnect': 'Сохранить и открыть',
+
   'hostDetails.plugin.title': 'Подключение плагина',
   'hostDetails.plugin.provider.placeholder': 'Выберите провайдер подключения',
   'hostDetails.plugin.provider.empty': 'Провайдеры подключения не установлены',

application/i18n/locales/undoLastTurnLocales.test.ts

@@ -0,0 +1,20 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import en from './en.ts';
+import ru from './ru.ts';
+import es from './es.ts';
+import zhCN from './zh-CN.ts';
+import zhTW from './zh-TW.ts';
+
+const UNDO_KEYS = [
+  'ai.chat.undoLastTurn',
+  'ai.chat.undoLastTurnNotice',
+] as const;
+
+test('Undo-last-turn UI is localized in every supported locale', () => {
+  for (const [name, messages] of Object.entries({ en, es, 'zh-CN': zhCN, 'zh-TW': zhTW, ru })) {
+    const missing = UNDO_KEYS.filter(key => !messages[key]);
+    assert.deepEqual(missing, [], `${name} is missing undo-last-turn labels`);
+  }
+});

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

@@ -522,13 +522,21 @@ export const zhCNAiMessages: Messages = {
   'ai.chat.hoursAgo': '{n}小时前',
   'ai.chat.daysAgo': '{n}天前',
   'ai.chat.newChat': '新对话',
+  'ai.chat.undoLastTurn': '撤销上一轮',
+  'ai.chat.undoLastTurnNotice': "原对话已保留。已执行的命令和文件修改不会撤销；之前保存的完整输出和后台任务，请回原对话查看。",
   'ai.chat.allSessions': '所有会话',
   'ai.chat.loadEarlierMessages': '加载更早的消息（还有 {n} 条）',
   'ai.chat.jumpNav': '跳转到消息',
   'ai.chat.jumpUntitled': '（空消息）',
   'ai.chat.usedTools': '已使用 {n} 个工具',
   'ai.chat.loadMoreSessions': '加载更多会话（还有 {n} 条）',
+  'ai.chat.searchSessions': '搜索标题和近期内容…',
+  'ai.chat.clearSessionSearch': '清空会话搜索',
+  'ai.chat.searchSessionsHint': '搜索标题，并优先搜索较新的消息和条目；超长消息及工具输出仅搜索开头的有限部分。这不是全文搜索。',
+  'ai.chat.noMatchingSessions': '标题和近期保留的内容中没有匹配结果',
   'ai.chat.noSessions': '没有历史会话',
+  'ai.chat.forkFromHere': '从此处分叉',
+  'ai.chat.forkCreated': '已分叉到新对话，原对话保留在历史中。',
   'ai.chat.retryHint': '你可以重新发送消息来重试。',
   'ai.chat.approvalTimeout': '工具审批已超时（5 分钟）。你可以重新发送消息来重试。',
   'ai.chat.menuHosts': '主机',

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

@@ -740,6 +740,7 @@ export const zhCNCoreMessages: Messages = {
   'vault.tree.expandAll': '展开全部',
   'vault.tree.collapseAll': '折叠全部',
   'vault.hosts.newHost': '新建主机',
+  'vault.hosts.newLocalShell': '本地终端 (CMD)',
   'vault.hosts.newGroup': '新建分组',
   'vault.hosts.import': '导入',
   'vault.hosts.export': '导出',
@@ -765,6 +766,9 @@ export const zhCNCoreMessages: Messages = {
   'vault.hosts.deleteMultiple.success': '已删除 {count} 个主机',
   'vault.hosts.connectSelected': '连接 ({count})',
   'vault.hosts.connectMultiple.success': '正在连接 {count} 个主机',
+  'vault.hosts.moveSelected': '移动到分组 ({count})',
+  'vault.hosts.moveSelected.description': '将选中的主机移动到现有分组，也可移出分组。选中的分组本身不会移动。',
+  'vault.hosts.moveMultiple.success': '已将 {count} 个主机移动到 {group}',
   'vault.hosts.moveToGroup.success': '已将 {host} 移动到 {group}',
   'vault.hosts.errors.nameRequired': '主机名称不能为空。',
   'vault.hosts.empty.title': '设置你的主机',

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

@@ -390,6 +390,21 @@ export const zhCNVaultMessages: Messages = {
   'hostDetails.addTag': '添加标签...',
   'hostDetails.createTag': '创建标签',
   'hostDetails.createGroup': '创建分组',
+  // 本地终端（CMD）主机条目
+  'localShell.subtitle': '本地终端',
+  'localShell.panel.title': '新建本地终端',
+  'localShell.panel.title.edit': '编辑本地终端',
+  'localShell.field.label': '名称',
+  'localShell.field.labelPlaceholder': '例如：项目 A · CMD',
+  'localShell.field.shell': 'Shell',
+  'localShell.field.shellDefault': '系统默认 Shell',
+  'localShell.field.shellDefaultDesc': '留空则使用设置 → 终端中配置的默认本地 Shell。',
+  'localShell.field.shellEmpty': '未发现可用 Shell',
+  'localShell.field.shellResolved': '启动 {command}',
+  'localShell.field.startDir': '启动目录',
+  'localShell.field.startDirPlaceholder': '继承全局起始目录（未设置时为主目录）',
+  'localShell.saveAndConnect': '保存并打开',
+
   'hostDetails.plugin.title': '插件连接',
   'hostDetails.plugin.provider.placeholder': '选择连接提供程序',
   'hostDetails.plugin.provider.empty': '未安装连接提供程序',

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

@@ -512,13 +512,21 @@ export const zhTWAiMessages: Messages = {
   'ai.chat.hoursAgo': '{n}小時前',
   'ai.chat.daysAgo': '{n}天前',
   'ai.chat.newChat': '新對話',
+  'ai.chat.undoLastTurn': '復原上一輪',
+  'ai.chat.undoLastTurnNotice': "原對話已保留。已執行的命令和檔案修改不會復原；之前儲存的完整輸出和背景工作，請回原對話查看。",
   'ai.chat.allSessions': '所有工作階段',
   'ai.chat.loadEarlierMessages': '載入更早的訊息（還有 {n} 條）',
   'ai.chat.jumpNav': '跳轉到訊息',
   'ai.chat.jumpUntitled': '（空訊息）',
   'ai.chat.usedTools': '已使用 {n} 個工具',
   'ai.chat.loadMoreSessions': '載入更多工作階段（還有 {n} 條）',
+  'ai.chat.searchSessions': '搜尋標題和近期內容…',
+  'ai.chat.clearSessionSearch': '清空會話搜尋',
+  'ai.chat.searchSessionsHint': '搜尋標題，並優先搜尋較新的訊息與項目；超長訊息與工具輸出僅搜尋開頭的有限部分。這不是全文搜尋。',
+  'ai.chat.noMatchingSessions': '標題和近期保留的內容中沒有符合的結果',
   'ai.chat.noSessions': '沒有歷史工作階段',
+  'ai.chat.forkFromHere': '從此處分叉',
+  'ai.chat.forkCreated': '已分叉到新對話，原對話保留在歷史中。',
   'ai.chat.retryHint': '你可以重新發送訊息來重試。',
   'ai.chat.approvalTimeout': '工具核准已超時（5 分鐘）。你可以重新發送訊息來重試。',
   'ai.chat.menuHosts': '主機',

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

@@ -742,6 +742,7 @@ export const zhTWCoreMessages: Messages = {
   'vault.tree.expandAll': '展開全部',
   'vault.tree.collapseAll': '摺疊全部',
   'vault.hosts.newHost': '新增主機',
+  'vault.hosts.newLocalShell': '本地終端 (CMD)',
   'vault.hosts.newGroup': '新增群組',
   'vault.hosts.import': '匯入',
   'vault.hosts.export': '匯出',
@@ -767,6 +768,9 @@ export const zhTWCoreMessages: Messages = {
   'vault.hosts.deleteMultiple.success': '已刪除 {count} 個主機',
   'vault.hosts.connectSelected': '連線 ({count})',
   'vault.hosts.connectMultiple.success': '正在連線 {count} 個主機',
+  'vault.hosts.moveSelected': '移動到群組 ({count})',
+  'vault.hosts.moveSelected.description': '將選取的主機移動到現有群組，也可移出群組。選取的群組本身不會移動。',
+  'vault.hosts.moveMultiple.success': '已將 {count} 個主機移動到 {group}',
   'vault.hosts.moveToGroup.success': '已將 {host} 移動到 {group}',
   'vault.hosts.errors.nameRequired': '主機名稱不能為空。',
   'vault.hosts.empty.title': '設定你的主機',

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

@@ -390,6 +390,21 @@ export const zhTWVaultMessages: Messages = {
   'hostDetails.addTag': '新增標籤...',
   'hostDetails.createTag': '建立標籤',
   'hostDetails.createGroup': '建立群組',
+  // 本地終端（CMD）主機項目
+  'localShell.subtitle': '本地終端',
+  'localShell.panel.title': '新增本地終端',
+  'localShell.panel.title.edit': '編輯本地終端',
+  'localShell.field.label': '名稱',
+  'localShell.field.labelPlaceholder': '例如：專案 A · CMD',
+  'localShell.field.shell': 'Shell',
+  'localShell.field.shellDefault': '系統預設 Shell',
+  'localShell.field.shellDefaultDesc': '留空則使用設定 → 終端中設定的預設本地 Shell。',
+  'localShell.field.shellEmpty': '未找到可用的 Shell',
+  'localShell.field.shellResolved': '啟動 {command}',
+  'localShell.field.startDir': '啟動目錄',
+  'localShell.field.startDirPlaceholder': '繼承全域起始目錄（未設定時為主目錄）',
+  'localShell.saveAndConnect': '儲存並開啟',
+
   'hostDetails.plugin.title': '外掛程式連線',
   'hostDetails.plugin.provider.placeholder': '選擇連線提供者',
   'hostDetails.plugin.provider.empty': '尚未安裝連線提供者',

application/state/aiStateSnapshots.test.ts

@@ -466,6 +466,115 @@ test('writeSessionsForStorage reduces several small sessions to fit a sub-512 KB
   }
 });
 
+test('serializeSessionsForStorage truncates slightly-over-cap tool results to strictly smaller sizes', async () => {
+  const { serializeSessionsForStorage } = await import('./aiStateSnapshots');
+  // Just over the 8 KiB cap: the truncation marker must not make the degraded
+  // copy larger than the original, or the ladder could evict a session whose
+  // unmodified JSON would have fit the budget.
+  for (const oversize of [8193, 8266, 20000]) {
+    const session = makeSession('near-cap', 1, [{
+      id: 'tool-message',
+      role: 'tool',
+      content: '',
+      timestamp: 1,
+      toolResults: [{ toolCallId: 'call-1', content: 'z'.repeat(oversize) }],
+    }]);
+    const fullJson = JSON.stringify([session]);
+    const result = serializeSessionsForStorage([session], fullJson.length - 10);
+    const content = result.sessions[0].messages[0].toolResults?.[0].content ?? '';
+    assert.ok(content.length <= 8 * 1024, `cap respected for ${oversize}`);
+    assert.ok(
+      JSON.stringify(result.sessions).length < fullJson.length,
+      `degraded copy smaller than original for ${oversize}`,
+    );
+    assert.ok(content.includes('truncated'));
+  }
+});
+
+test('serializeSessionsForStorage sheds oversized tool output before dropping visible sessions', async () => {
+  const { serializeSessionsForStorage } = await import('./aiStateSnapshots');
+  const newest = makeSession('newest', 2, [{
+    id: 'new-message',
+    role: 'assistant',
+    content: 'still-open chat',
+    timestamp: 2,
+  }]);
+  const toolBulk = makeSession('tool-bulk', 1, [{
+    id: 'tool-message',
+    role: 'tool',
+    content: '',
+    timestamp: 1,
+    toolResults: [{ toolCallId: 'call-1', content: 'z'.repeat(400 * 1024) }],
+  }]);
+
+  const result = serializeSessionsForStorage([toolBulk, newest], 100 * 1024);
+
+  // The bloated tool result must not evict the other visible chat.
+  assert.deepEqual(result.sessions.map(session => session.id), ['newest', 'tool-bulk']);
+  assert.ok(result.json.length <= 100 * 1024);
+  const persistedToolContent = result.sessions[1].messages[0].toolResults?.[0].content;
+  assert.ok(persistedToolContent);
+  assert.ok(persistedToolContent.length <= 9 * 1024);
+  assert.ok(persistedToolContent.includes('truncated'));
+  assert.ok(persistedToolContent.startsWith('zzz'));
+  assert.equal(result.sessions[0].messages[0].content, 'still-open chat');
+});
+
+test('writeSessionsForStorage keeps every chat by shedding tool output under quota pressure', async () => {
+  const { writeSessionsForStorage } = await import('./aiStateSnapshots');
+  let stored: string | undefined;
+  const previousLocalStorage = globalThis.localStorage;
+  Object.defineProperty(globalThis, 'localStorage', {
+    configurable: true,
+    value: {
+      getItem: () => null,
+      setItem: (_key: string, value: string) => {
+        if (value.length > 300 * 1024) {
+          throw new DOMException('quota exceeded', 'QuotaExceededError');
+        }
+        stored = value;
+      },
+      removeItem: () => {},
+    },
+  });
+
+  try {
+    const sessions = Array.from({ length: 10 }, (_, index) => makeSession(
+      `session-${index}`,
+      10 - index,
+      [{
+        id: `message-${index}`,
+        role: 'tool' as const,
+        content: '',
+        timestamp: index,
+        toolResults: [{ toolCallId: `call-${index}`, content: 'z'.repeat(40 * 1024) }],
+      }],
+    ));
+
+    assert.equal(writeSessionsForStorage(sessions), true);
+    assert.ok(stored);
+    assert.ok(stored.length <= 300 * 1024);
+    const persisted = JSON.parse(stored) as AISession[];
+    assert.deepEqual(
+      persisted.map(session => session.id),
+      sessions.map(session => session.id),
+    );
+    // Degradation sheds only as many messages as the budget demands, so at
+    // least one chat keeps its full tool output while the persisted set stays
+    // complete. Assert completion first; truncation second.
+    const shedContents = persisted.map(
+      session => session.messages[0].toolResults?.[0].content ?? '',
+    );
+    assert.ok(shedContents.some(content => content.includes('truncated')));
+    assert.ok(shedContents.some(content => content.startsWith('zzz') && !content.includes('truncated')));
+  } finally {
+    Object.defineProperty(globalThis, 'localStorage', {
+      configurable: true,
+      value: previousLocalStorage,
+    });
+  }
+});
+
 test('writeSessionsForStorage makes a final attempt with only the newest session', async () => {
   const { writeSessionsForStorage } = await import('./aiStateSnapshots');
   const writes: string[] = [];

application/state/aiStateSnapshots.ts

@@ -195,12 +195,40 @@ const RETRY_SESSIONS_JSON_BYTES = [
   128 * 1024,
 ] as const;
 
+/**
+ * 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.
+ */
+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; ${omitted} characters of tool output omitted`;
+  }
+  return `${content.slice(0, half)}${marker}${content.slice(content.length - half)}`;
+}
+
 /**
  * Remove `reasoningEncryptedContent` ciphertext from a message's persisted
- * continuation. The ciphertext exists so stateless Responses turns can replay
- * prior reasoning items; it is also by far the largest per-message payload.
- * When storage pressure forces it, dropping the ciphertext keeps the visible
- * conversation intact at the cost of reasoning replay for affected messages.
+ * 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,
@@ -218,7 +246,7 @@ function stripReasoningEncryptedContent(
   return Object.keys(stripped).length ? stripped : undefined;
 }
 
-function stripEncryptedReasoningFromMessage(message: AISession['messages'][number]) {
+function stripReasoningCiphertextFromMessage(message: AISession['messages'][number]) {
   const continuation = message.providerContinuation;
   if (!continuation?.reasoningParts) return message;
   let changed = false;
@@ -239,6 +267,22 @@ function stripEncryptedReasoningFromMessage(message: AISession['messages'][numbe
   };
 }
 
+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 => {
@@ -259,7 +303,7 @@ function stripCompactedEncryptedReasoningFromSession(session: AISession): AISess
   let changed = false;
   const messages = session.messages.map((message, index) => {
     if (index >= compactedMessageCount) return message;
-    const stripped = stripEncryptedReasoningFromMessage(message);
+    const stripped = stripReasoningCiphertextFromMessage(message);
     if (stripped !== message) changed = true;
     return stripped;
   });
@@ -310,6 +354,11 @@ export function pruneSessionsForStorage(sessions: AISession[]): AISession[] {
  * 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[],
@@ -321,13 +370,13 @@ export function serializeSessionsForStorage(
     // before deciding whether the newest session deserves full protection;
     // otherwise dead metadata can evict other visible conversations.
     const session = stripCompactedEncryptedReasoningFromSession(rawSession);
-    const ciphertextMessages = session.messages.flatMap((message, index) => {
-      const strippedMessage = stripEncryptedReasoningFromMessage(message);
-      if (strippedMessage === message) return [];
+    const degradableMessages = session.messages.flatMap((message, index) => {
+      const degradedMessage = stripEncryptedReasoningFromMessage(message);
+      if (degradedMessage === message) return [];
       return [{
         index,
-        strippedMessage,
-        jsonLengthDelta: JSON.stringify(strippedMessage).length - JSON.stringify(message).length,
+        degradedMessage,
+        jsonLengthDelta: JSON.stringify(degradedMessage).length - JSON.stringify(message).length,
       }];
     });
     const strippedSession = stripEncryptedReasoningFromSession(session);
@@ -339,7 +388,7 @@ export function serializeSessionsForStorage(
       strippedJson: strippedSession === session
         ? json
         : JSON.stringify(strippedSession),
-      ciphertextMessages,
+      degradableMessages,
     };
   });
 
@@ -364,11 +413,12 @@ export function serializeSessionsForStorage(
     minimalLength -= removed.strippedJson.length + 1;
   }
 
-  // Then keep full continuation data for the retained sessions and remove
-  // replay-only ciphertext from the oldest retained sessions only as needed,
-  // never touching the protected newest session. Within one session, remove
-  // 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.
+  // 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;
@@ -378,27 +428,27 @@ export function serializeSessionsForStorage(
     index -= 1
   ) {
     const current = serialized[index];
-    let strippedMessageCount = 0;
-    while (jsonLength > budgetBytes && strippedMessageCount < current.ciphertextMessages.length) {
-      jsonLength += current.ciphertextMessages[strippedMessageCount].jsonLengthDelta;
-      strippedMessageCount += 1;
+    let degradedMessageCount = 0;
+    while (jsonLength > budgetBytes && degradedMessageCount < current.degradableMessages.length) {
+      jsonLength += current.degradableMessages[degradedMessageCount].jsonLengthDelta;
+      degradedMessageCount += 1;
     }
-    if (strippedMessageCount > 0) {
-      const strippedMessagesByIndex = new Map(
-        current.ciphertextMessages
-          .slice(0, strippedMessageCount)
-          .map(entry => [entry.index, entry.strippedMessage] as const),
+    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) => (
-          strippedMessagesByIndex.get(messageIndex) ?? message
+          degradedMessagesByIndex.get(messageIndex) ?? message
         )),
       };
       const nextJson = JSON.stringify(nextSession);
       const projectedJsonLength = current.json.length
-        + current.ciphertextMessages
-          .slice(0, strippedMessageCount)
+        + current.degradableMessages
+          .slice(0, degradedMessageCount)
           .reduce((total, entry) => total + entry.jsonLengthDelta, 0);
       jsonLength += nextJson.length - projectedJsonLength;
       serialized[index] = {

application/state/resolveTerminalSessionExitIntent.test.ts

@@ -8,10 +8,20 @@ import {
   shouldRevealTerminalPopupOnExit,
 } from "./resolveTerminalSessionExitIntent.ts";
 
-test("normal backend exited events close the session tab", () => {
+test("backend exited events close the session tab only when auto-close is enabled", () => {
+  assert.deepEqual(
+    resolveTerminalSessionExitIntent({ reason: "exited", exitCode: 0 }, true),
+    { kind: "closeSession" },
+  );
+});
+
+test("omitted auto-close setting keeps the session tab on a clean exit", () => {
+  // The fallback for callers that have not loaded the terminal setting yet:
+  // keep the tab so a jump host / bastion reaping a session (a clean exit)
+  // never silently deletes the user's scrollback.
   assert.deepEqual(
     resolveTerminalSessionExitIntent({ reason: "exited", exitCode: 0 }),
-    { kind: "closeSession" },
+    { kind: "markDisconnected" },
   );
 });
 
@@ -57,11 +67,19 @@ test("backend closed events keep the tab and mark it disconnected", () => {
   );
 });
 
+test("administrative exit-signal disconnects keep the tab", () => {
+  assert.deepEqual(
+    resolveTerminalSessionExitIntent({ reason: "signaled", exitSignal: "SIGHUP" }, true),
+    { kind: "markDisconnected" },
+  );
+});
+
 test("terminal popup only auto-closes after clean command exit", () => {
   assert.equal(shouldCloseTerminalPopupOnExit({ reason: "exited", exitCode: 0 }), true);
   assert.equal(shouldCloseTerminalPopupOnExit({ reason: "exited", exitCode: 1 }), false);
   assert.equal(shouldCloseTerminalPopupOnExit({ reason: "error", error: "connection reset" }), false);
   assert.equal(shouldCloseTerminalPopupOnExit({ reason: "closed", exitCode: 0 }), false);
+  assert.equal(shouldCloseTerminalPopupOnExit({ reason: "signaled", exitSignal: "SIGHUP" }), false);
 });
 
 test("disabled auto-close keeps command and attached terminal popups open", () => {
@@ -133,6 +151,17 @@ test("exit messages show the reported code for a real remote exit", () => {
   );
 });
 
+test("an administrative exit-signal renders as a remote signal, not a clean code", () => {
+  assert.equal(
+    formatSessionClosedExitMessage({ reason: "signaled", exitSignal: "SIGHUP" }),
+    "\r\n[session closed by remote signal]",
+  );
+  assert.equal(
+    formatSessionClosedExitMessage({ reason: "closed", exitSignal: "SIGTERM" }),
+    "\r\n[session closed by remote signal]",
+  );
+});
+
 test("a channel closed without exit-status or exit-signal must not render as code 0", () => {
   assert.equal(
     formatSessionClosedExitMessage({
@@ -150,3 +179,25 @@ test("exit messages without a reported code stay plain instead of showing a sent
   );
   assert.equal(formatSessionClosedExitMessage({}), "\r\n[session closed]");
 });
+
+test("infrastructure teardowns must not render a numeric code as a clean exit (#3631)", () => {
+  // A terminal-worker exit broadcast carries the worker's own exit status
+  // (graceful drain = 0). It belongs to the infrastructure failure, not to
+  // any remote shell, so it must never read as "session closed (code 0)".
+  assert.equal(
+    formatSessionClosedExitMessage({
+      reason: "error",
+      exitCode: 0,
+      error: "Terminal worker exited with code 0",
+    }),
+    "\r\n[session closed unexpectedly]",
+  );
+  assert.equal(
+    formatSessionClosedExitMessage({ reason: "error", exitCode: 1 }),
+    "\r\n[session closed unexpectedly]",
+  );
+  assert.equal(
+    formatSessionClosedExitMessage({ reason: "error" }),
+    "\r\n[session closed unexpectedly]",
+  );
+});

application/state/resolveTerminalSessionExitIntent.ts

@@ -4,7 +4,10 @@ export type TerminalSessionExitEvent = {
   exitCode?: number;
   signal?: number;
   error?: string;
-  reason?: "exited" | "error" | "timeout" | "closed";
+  reason?: "exited" | "error" | "timeout" | "closed" | "signaled";
+  // ssh2 exit-signal name ("SIGHUP", "SIGTERM", ...). Set when the server
+  // terminated the session process. Distinct from a transport "closed".
+  exitSignal?: string;
   // True when the remote closed the channel without sending exit-status or
   // exit-signal (#3591): no numeric exit code exists, and the renderer shows
   // a distinct message instead of a misleading "code 0".
@@ -16,6 +19,13 @@ export function formatSessionClosedExitMessage(evt: TerminalSessionExitEvent): s
   if (evt?.remoteClosedWithoutExitStatus) {
     return "\r\n[session closed by remote (no exit status)]";
   }
+  if (evt?.reason === "signaled" || (typeof evt?.exitSignal === "string" && evt.exitSignal.trim().length > 0)) {
+    return "\r\n[session closed by remote signal]";
+  }
+  // Infrastructure exit codes do not describe the remote shell's status.
+  if (evt?.reason === "error") {
+    return "\r\n[session closed unexpectedly]";
+  }
   return `\r\n[session closed${evt?.exitCode !== undefined ? ` (code ${evt.exitCode})` : ""}]`;
 }
 
@@ -34,7 +44,11 @@ function isConfirmedCleanExit(evt: TerminalSessionExitEvent): boolean {
 
 export function resolveTerminalSessionExitIntent(
   evt: TerminalSessionExitEvent,
-  autoCloseOnExit = true,
+  // Keep-tab is the safe default: a caller that has not loaded the terminal
+  // setting yet must not silently delete a session tab. Remote graceful
+  // channel closes (e.g. a jump host reaping an idle session) are reported
+  // as a clean exit, so an unavailable setting must not re-enable closing.
+  autoCloseOnExit = false,
 ): TerminalSessionExitIntent {
   if (autoCloseOnExit && isConfirmedCleanExit(evt)) {
     return { kind: "closeSession" };

application/state/sessionFactories.localVaultHost.test.ts

@@ -0,0 +1,244 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { createHostTerminalSession } from "./sessionFactories.ts";
+import { createLocalTerminalSession } from "./sessionFactories.ts";
+import { resolveHostDefaultLocalShell } from "../../domain/localShellHost";
+import { resolveTerminalSessionHost } from "../../domain/terminalHostResolution";
+import type { Host } from "../../domain/models";
+
+const localVaultHost = (overrides: Partial<Host> = {}): Host => ({
+  id: "local-vault-1",
+  label: "Project A CMD",
+  hostname: "localhost",
+  username: "",
+  group: "Projects/A",
+  tags: ["local"],
+  os: "linux",
+  protocol: "local",
+  createdAt: 0,
+  ...overrides,
+});
+
+test("createHostTerminalSession copies local shell fields for local vault hosts", () => {
+  const host = localVaultHost({
+    localShell: "wsl-ubuntu",
+    localShellArgs: ["--cd", "/work"],
+    localShellName: "Ubuntu (WSL)",
+    localShellIcon: "ubuntu",
+    localStartDir: "/work",
+  });
+  const session = createHostTerminalSession("session-1", host);
+
+  assert.equal(session.protocol, "local");
+  assert.equal(session.hostId, "local-vault-1");
+  assert.equal(session.localShell, "wsl-ubuntu");
+  assert.deepEqual(session.localShellArgs, ["--cd", "/work"]);
+  assert.equal(session.localShellName, "Ubuntu (WSL)");
+  assert.equal(session.localShellIcon, "ubuntu");
+  assert.equal(session.localStartDir, "/work");
+});
+
+test("createHostTerminalSession does not add local shell fields to SSH hosts", () => {
+  const host: Host = {
+    ...localVaultHost({ protocol: "ssh", hostname: "example.com", port: 22 }),
+  } as Host;
+  const session = createHostTerminalSession("session-2", host);
+
+  assert.equal(session.protocol, "ssh");
+  assert.equal(session.localShell, undefined);
+  assert.equal(session.localShellName, undefined);
+  assert.equal(session.shellType, undefined);
+});
+
+test("createHostTerminalSession classifies the shell for CMD/PowerShell local vault hosts", () => {
+  const cmd = createHostTerminalSession("session-cmd", localVaultHost({ localShell: "cmd", os: "windows" }));
+  assert.equal(cmd.shellType, "cmd");
+
+  const pwsh = createHostTerminalSession("session-pwsh", localVaultHost({ localShell: "pwsh", os: "windows" }));
+  assert.equal(pwsh.shellType, "powershell");
+
+  // Discovered shell IDs persisted by the local-shell editor are not
+  // executable basenames, but they still resolve to POSIX shells at spawn
+  // time — WSL distros, Git Bash, and Cygwin all run a POSIX shell.
+  const wslId = createHostTerminalSession("session-wsl-id", localVaultHost({ localShell: "wsl-ubuntu", os: "windows" }));
+  assert.equal(wslId.shellType, "posix");
+
+  const gitBash = createHostTerminalSession("session-git-bash", localVaultHost({ localShell: "git-bash", os: "windows" }));
+  assert.equal(gitBash.shellType, "posix");
+
+  const cygwin = createHostTerminalSession("session-cygwin", localVaultHost({ localShell: "cygwin", os: "windows" }));
+  assert.equal(cygwin.shellType, "posix");
+
+  // Unix discovery emits disambiguated path-slug IDs when multiple
+  // installations share a basename (e.g. /bin/bash vs
+  // /opt/homebrew/bin/bash); the backend launches the resolved command, so
+  // the session must classify as that command's shell type, not "unknown".
+  const slugBash = createHostTerminalSession("session-slug-bash", localVaultHost({ localShell: "bin-bash", os: "macos" }));
+  assert.equal(slugBash.shellType, "posix");
+
+  const slugHomebrewBash = createHostTerminalSession(
+    "session-slug-homebrew",
+    localVaultHost({ localShell: "opt-homebrew-bin-bash", os: "macos" }),
+  );
+  assert.equal(slugHomebrewBash.shellType, "posix");
+
+  const customPowershellPath = createHostTerminalSession(
+    "session-pwsh-path",
+    localVaultHost({ localShell: "C:\\Program Files\\PowerShell\\7\\pwsh.exe", os: "windows" }),
+  );
+  assert.equal(customPowershellPath.shellType, "powershell");
+
+  // Default-shell hosts (empty localShell) launch the machine's OS default
+  // shell (the backend's own detection), so classification must use the
+  // runtime platform — not the saved host.os, which may describe a machine
+  // the host was synced/imported from. Node 22's navigator.userAgent is
+  // always "Node.js/<version>", so this test environment always classifies
+  // as POSIX regardless of the CI runner's real OS.
+  const windowsSyncedDefault = createHostTerminalSession("session-win-default", localVaultHost({ os: "windows" }));
+  assert.equal(windowsSyncedDefault.shellType, "posix");
+
+  const posixDefault = createHostTerminalSession("session-posix-default", localVaultHost({ os: "linux" }));
+  assert.equal(posixDefault.shellType, "posix");
+
+  const unknownCustom = createHostTerminalSession(
+    "session-unknown",
+    localVaultHost({ localShell: "/usr/local/bin/exotic-shell", os: "linux" }),
+  );
+  assert.equal(unknownCustom.shellType, "unknown");
+});
+
+test("createLocalTerminalSession is unaffected by vault local hosts", () => {
+  const session = createLocalTerminalSession("session-3", { shellName: "CMD" });
+  assert.equal(session.hostId, "local-terminal");
+  assert.equal(session.localShellName, "CMD");
+});
+
+test("createHostTerminalSession snapshots an explicit no-args local shell as an empty array", () => {
+  // Legacy vault hosts can predate localShellArgs, so the field may be
+  // absent on the Host; the session snapshot must still distinguish
+  // "launched with no args" ([]) from "no metadata" (undefined).
+  const host = localVaultHost({
+    localShell: "cmd",
+    localShellName: "Command Prompt",
+    os: "windows",
+  });
+  const session = createHostTerminalSession("session-noargs", host);
+
+  assert.ok(Array.isArray(session.localShellArgs), "args snapshot must be present");
+  assert.deepEqual(session.localShellArgs, []);
+});
+
+test("resolveTerminalSessionHost does not merge edited host args into a no-args local snapshot", () => {
+  const launchTimeHost = localVaultHost({
+    localShell: "cmd",
+    localShellName: "Command Prompt",
+    os: "windows",
+  });
+  const session = createHostTerminalSession("session-1", launchTimeHost);
+
+  // The saved host was later edited to a shell with args; the snapshot taken
+  // at launch time must win so the clone relaunches CMD, not WSL.
+  const editedHost: Host = {
+    ...launchTimeHost,
+    label: "Edited WSL",
+    localShell: "wsl-ubuntu",
+    localShellArgs: ["--cd", "/elsewhere"],
+    localShellName: "Ubuntu (WSL)",
+    localStartDir: "/elsewhere",
+  };
+
+  const resolved = resolveTerminalSessionHost({
+    session,
+    hosts: [editedHost],
+    groupConfigs: [],
+    proxyProfiles: [],
+    localOs: "windows",
+  });
+
+  assert.equal(resolved.localShell, "cmd");
+  assert.deepEqual(resolved.localShellArgs, []);
+  assert.equal(resolved.localShellName, "Command Prompt");
+});
+
+test("createHostTerminalSession snapshots an inherited start directory for Copy Tab", () => {
+  // The saved host has no directory of its own, so the starter launches in
+  // Settings > Terminal's localStartDir. That effective directory has to be
+  // recorded now; overlay falls back to the host or the current setting when
+  // the session field is missing.
+  const saved = localVaultHost({
+    localShell: "bash",
+    localShellName: "Bash",
+    localStartDir: "",
+  });
+  const effective = resolveHostDefaultLocalShell(saved, {
+    terminalSettings: { localStartDir: "/home/alice/global" },
+  });
+  const session = createHostTerminalSession("session-inherit", effective);
+  assert.equal(session.localStartDir, "/home/alice/global");
+
+  const changedSettings = {
+    terminalSettings: { localShell: "fish", localStartDir: "/home/alice/changed" },
+  };
+  const afterSettingsChange = resolveTerminalSessionHost({
+    session,
+    hosts: [saved],
+    groupConfigs: [],
+    proxyProfiles: [],
+    localOs: "linux",
+    defaultLocalShell: changedSettings,
+  });
+  assert.equal(afterSettingsChange.localStartDir, "/home/alice/global");
+
+  const afterHostEdit = resolveTerminalSessionHost({
+    session,
+    hosts: [{ ...saved, localStartDir: "/home/alice/edited" }],
+    groupConfigs: [],
+    proxyProfiles: [],
+    localOs: "linux",
+    defaultLocalShell: changedSettings,
+  });
+  assert.equal(afterHostEdit.localStartDir, "/home/alice/global");
+});
+
+test("createHostTerminalSession snapshots an inherited start directory for a default shell host", () => {
+  const saved = localVaultHost();
+  const effective = resolveHostDefaultLocalShell(saved, {
+    terminalSettings: { localShell: "bash", localStartDir: "/home/alice/global" },
+    resolveShellSetting: () => ({ command: "/bin/bash", args: ["-l"] }),
+  });
+  const session = createHostTerminalSession("session-default-shell", effective);
+
+  assert.equal(session.localShell, "/bin/bash");
+  assert.deepEqual(session.localShellArgs, ["-l"]);
+  assert.equal(session.localStartDir, "/home/alice/global");
+});
+
+test("resolveHostDefaultLocalShell keeps an explicit start directory and ignores non-local hosts", () => {
+  const explicit = localVaultHost({ localShell: "bash", localStartDir: "/work" });
+  const resolvedExplicit = resolveHostDefaultLocalShell(explicit, {
+    terminalSettings: { localStartDir: "/home/alice/global" },
+  });
+  assert.equal(resolvedExplicit.localStartDir, "/work");
+  assert.equal(createHostTerminalSession("session-explicit", resolvedExplicit).localStartDir, "/work");
+
+  const ssh = localVaultHost({ protocol: "ssh", hostname: "example.com", port: 22 });
+  const resolvedSsh = resolveHostDefaultLocalShell(ssh, {
+    terminalSettings: { localStartDir: "/home/alice/global" },
+  });
+  assert.equal(resolvedSsh.localStartDir, undefined);
+  assert.equal(resolvedSsh, ssh);
+});
+
+test("saved local sessions use the ordinary local username marker without changing vault or SSH credentials", () => {
+  const saved = localVaultHost({ username: "" });
+  const ordinary = createLocalTerminalSession("ordinary-local");
+  const opened = createHostTerminalSession("saved-local", saved);
+  assert.equal(opened.username, ordinary.username);
+  assert.equal(opened.username, "local");
+  assert.equal(saved.username, "");
+  const remote = { ...saved, protocol: "ssh" as const, username: "remote-user" };
+  assert.equal(createHostTerminalSession("ssh-session", remote).username, "remote-user");
+  const resolved = resolveTerminalSessionHost({ session: opened, hosts: [saved], groupConfigs: [], proxyProfiles: [], localOs: "linux" });
+  assert.equal(resolved.username, ordinary.username, "terminal-run scripts receive the same local marker");
+});

application/state/sessionFactories.test.ts

@@ -4,7 +4,7 @@ import test from "node:test";
 import type { Host } from "../../domain/models";
 import { prepareSerialConfigForSavedHost } from "../../domain/serialBackspace";
 import { buildTelnetDeepLinkConnectionHost } from "../../domain/telnetDeepLink";
-import { resolveEffectiveTerminalHost } from "../../domain/terminalHostResolution";
+import { resolveEffectiveTerminalHost, resolveTerminalSessionHost } from "../../domain/terminalHostResolution";
 import {
   createHostTerminalSession,
   createSerialTerminalSession,
@@ -171,3 +171,16 @@ test("host session factories snapshot plugin connection configuration", () => {
   assert.deepEqual(workspace.pluginConnection, pluginConnection);
   assert.notEqual(workspace.pluginConnection, pluginConnection);
 });
+
+test("local sessions preserve intentionally absent display metadata when the saved shell changes", () => {
+  const original = host({ protocol: "local", hostname: "localhost", localShell: "/bin/bash" });
+  const source = createHostTerminalSession("original-bash", original);
+  const edited = { ...original, localShell: "/bin/zsh", localShellName: "Zsh", localShellIcon: "zsh" };
+  const copied = resolveTerminalSessionHost({ session: source, hosts: [edited], groupConfigs: [], proxyProfiles: [], localOs: "macos" });
+  assert.equal(copied.localShell, "/bin/bash");
+  assert.equal(copied.localShellName, "");
+  assert.equal(copied.localShellIcon, "");
+  const named = createHostTerminalSession("named-zsh", edited);
+  assert.equal(named.localShellName, "Zsh");
+  assert.equal(named.localShellIcon, "zsh");
+});

application/state/sessionFactories.ts

@@ -1,4 +1,5 @@
 import type { Host, SerialConfig, TerminalSession } from "../../domain/models";
+import { classifyLocalShellType } from "../../lib/localShell";
 
 export interface LocalTerminalOptions {
   shellType?: TerminalSession["shellType"];
@@ -18,6 +19,28 @@ export interface LocalTerminalOptions {
  */
 export const LOCAL_TERMINAL_HOST_ID = "local-terminal";
 
+/**
+ * [] captures the absence of custom arguments instead of inheriting them
+ * from a later host edit. The starter still applies backend defaults to []
+ * and undefined alike. Share the array to preserve pane equality checks.
+ */
+const EMPTY_LOCAL_SHELL_ARGS: string[] = [];
+
+/**
+ * Platform string describing the machine that is launching the session.
+ *
+ * Vault local hosts can be synced/imported from another OS, so their saved
+ * `host.os` describes the source machine. When the host has no explicit
+ * shell (`localShell` empty), `startLocalSession` spawns the current
+ * machine's OS default shell, so classification must fall back to the
+ * runtime platform — not the persisted host OS — or a Windows host opened
+ * on Linux would be tagged "powershell" while Bash actually runs.
+ */
+const runtimePlatformLike = (): string | undefined => {
+  if (typeof navigator === "undefined") return undefined;
+  return navigator.userAgent || navigator.platform || undefined;
+};
+
 export const createLocalTerminalSession = (
   sessionId: string,
   options?: LocalTerminalOptions,
@@ -113,6 +136,30 @@ export const createHostTerminalSession = (
     moshEnabled: host.moshEnabled,
     etEnabled: host.etEnabled,
     charset: host.charset,
+    // Local-shell vault hosts carry the per-host shell selection into the
+    // session (the bridge resolves discovered shell ids at spawn time).
+    // shellType matches ordinary local-terminal creation so captured-CWD
+    // restore can reject POSIX injection into CMD/PowerShell sessions.
+    ...(host.protocol === "local" ? {
+      username: "local",
+      // With an explicit shell the basename classifies it on any OS, so the
+      // saved host.os stays the fallback; a default-shell host launches the
+      // current machine's OS default, so classify against the runtime.
+      shellType: classifyLocalShellType(
+        host.localShell,
+        host.localShell?.trim() ? host.os : runtimePlatformLike(),
+      ),
+      localShell: host.localShell ?? "",
+      // Preserve field presence: an edited host must not contribute its args
+      // to a session that was launched with an explicit shell and no args.
+      localShellArgs: host.localShellArgs ?? EMPTY_LOCAL_SHELL_ARGS,
+      localShellName: host.localShellName ?? "",
+      localShellIcon: host.localShellIcon ?? "",
+      // Effective directory from resolveHostDefaultLocalShell, including a
+      // Settings directory the saved host inherits. Copy Tab overlays this
+      // snapshot, so a later settings or vault edit cannot move the relaunch.
+      localStartDir: host.localStartDir || "~",
+    } : {}),
     ...(host.ephemeral ? { ephemeralHost: true } : {}),
     ...(host.autoOpenSftpPanel ? { autoOpenSidePanel: "sftp" as const } : {}),
   };

application/state/sessionHistorySearch.test.ts

@@ -0,0 +1,790 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import {
+  collectSessionSearchFields,
+  type SessionHistorySearchMessage,
+} from "../../domain/sessionHistorySearch.ts";
+import {
+  PINYIN_CACHE_MAX_CHARS,
+  getPinyinCacheStatsForTests,
+  resetPinyinCacheForTests,
+} from "../../lib/searchMatcher.ts";
+import { createSessionHistorySearch } from "./sessionHistorySearch.ts";
+
+// One instance for the whole file: it keeps the pre-factory semantics of every
+// test sharing (and clearing) a single cache.
+const { clearSessionHistorySearchCache, filterSessionHistory } = createSessionHistorySearch();
+
+// Fixture messages stay loosely typed: persisted sessions carry far richer
+// shapes (role, ids, payload fields, …) than the minimal searchable shapes,
+// and extra properties must remain structurally harmless.
+function createSession(
+  id: string,
+  title: string,
+  messages: Array<Record<string, unknown>>,
+) {
+  return {
+    id,
+    title,
+    messages: messages.map((message, index) => ({
+      id: `${id}-m${index}`,
+      role: "user",
+      content: "",
+      timestamp: index,
+      ...message,
+    })) as SessionHistorySearchMessage[],
+  };
+}
+
+test("filterSessionHistory matches titles and keeps order when query is blank", () => {
+  const sessions = [
+    createSession("a", "nginx restart", []),
+    createSession("b", "disk cleanup", []),
+  ];
+
+  for (const query of ["", "  \t\n"]) {
+    assert.deepEqual(filterSessionHistory(sessions, query), sessions);
+  }
+});
+
+test("filterSessionHistory handles special characters through the shared matcher", () => {
+  const sessions = [
+    createSession("a", "Ops", [{ content: "check [prod].json at /var/log/nginx" }]),
+    createSession("b", "Deploy", [{ content: "ship it" }]),
+  ];
+
+  assert.deepEqual(filterSessionHistory(sessions, "[prod].json"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "/var/log/nginx"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "[](){}"), []);
+});
+
+test("filterSessionHistory matches message content of user and assistant turns", () => {
+  const sessions = [
+    createSession("a", "Debugging", [
+      { role: "user", content: "why is sshd down on prod-3?" },
+      { role: "assistant", content: "let me check the journal" },
+    ]),
+    createSession("b", "Deploy notes", [
+      { role: "user", content: "ship release 1.2" },
+    ]),
+  ];
+
+  assert.deepEqual(filterSessionHistory(sessions, "sshd down"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "1.2"), [sessions[1]]);
+  assert.deepEqual(filterSessionHistory(sessions, "nothing here"), []);
+});
+
+test("filterSessionHistory ignores hidden system messages", () => {
+  const sessions = [
+    createSession("a", "Ops", [
+      { role: "system", content: "shared hidden prompt with marker text" },
+      { role: "user", content: "all clear" },
+    ]),
+    createSession("b", "Deploy", [
+      { role: "system", content: "shared hidden prompt with marker text" },
+      { role: "user", content: "ship it" },
+    ]),
+  ];
+
+  // A query found only inside system messages must not surface the sessions:
+  // the reopened conversation hides those messages, so a match would display
+  // no matching text.
+  assert.deepEqual(filterSessionHistory(sessions, "marker text"), []);
+});
+
+test("filterSessionHistory searches thinking and tool call/result content", () => {
+  const sessions = [
+    createSession("a", "Untitled", [
+      { role: "assistant", thinking: "the certificate expired" },
+    ]),
+    createSession("b", "Ops", [
+      {
+        role: "assistant",
+        toolCalls: [{ name: "systemctl", id: "t1", arguments: {} }],
+        toolResults: [{ toolCallId: "t1", content: "nginx failed to bind port" }],
+      },
+    ]),
+  ];
+
+  assert.deepEqual(filterSessionHistory(sessions, "certificate"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "systemctl"), [sessions[1]]);
+  assert.deepEqual(filterSessionHistory(sessions, "bind port"), [sessions[1]]);
+});
+
+test("filterSessionHistory matches text stored only in tool call arguments", () => {
+  const sessions = [
+    createSession("a", "Ops", [
+      {
+        role: "assistant",
+        toolCalls: [{
+          name: "shell",
+          id: "t1",
+          arguments: { command: "systemctl restart nginx" },
+        }],
+      },
+    ]),
+    createSession("b", "Deploy", [
+      {
+        role: "assistant",
+        toolCalls: [{ name: "file", id: "t2", arguments: {} }],
+      },
+    ]),
+  ];
+
+  assert.deepEqual(filterSessionHistory(sessions, "nginx"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "restart nginx"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "nothing here"), []);
+
+  const fields = collectSessionSearchFields(sessions[0]);
+  assert.ok(fields.some((field) => field.includes("systemctl restart nginx")));
+});
+
+test("filterSessionHistory matches persisted agent activities", () => {
+  const sessions = [
+    createSession("a", "Research", [
+      {
+        role: "assistant",
+        agentActivities: [
+          { id: "1", type: "web_search", status: "completed", query: "rust async runtime benchmarks" },
+        ],
+      },
+    ]),
+    createSession("b", "Refactor", [
+      {
+        role: "assistant",
+        agentActivities: [
+          {
+            id: "2",
+            type: "file_change",
+            status: "completed",
+            changes: [
+              { path: "src/sessionStore.ts", kind: "update" },
+              { path: "src/sessionStore.test.ts", kind: "add" },
+            ],
+          },
+        ],
+      },
+    ]),
+    createSession("c", "Plan", [
+      {
+        role: "assistant",
+        agentActivities: [
+          {
+            id: "3",
+            type: "plan_update",
+            status: "completed",
+            items: [
+              { text: "extract search collector", completed: true },
+              { text: "wire into drawer", completed: false },
+            ],
+          },
+          { id: "4", type: "warning", status: "completed", message: "rate limit hit" },
+        ],
+      },
+    ]),
+  ];
+
+  assert.deepEqual(filterSessionHistory(sessions, "async runtime"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "sessionStore.test"), [sessions[1]]);
+  assert.deepEqual(filterSessionHistory(sessions, "extract search collector"), [sessions[2]]);
+  assert.deepEqual(filterSessionHistory(sessions, "rate limit"), [sessions[2]]);
+  assert.deepEqual(filterSessionHistory(sessions, "nothing here"), []);
+
+  const fields = collectSessionSearchFields(sessions[2]);
+  assert.ok(fields.some((field) => field.includes("extract search collector")));
+  assert.ok(fields.some((field) => field.includes("rate limit hit")));
+});
+
+test("filterSessionHistory matches persisted error messages and attachment labels", () => {
+  const sessions = [
+    createSession("a", "Untitled", [
+      {
+        role: "assistant",
+        content: "",
+        errorInfo: { type: "provider", message: "upstream rate limit exceeded", retryable: true },
+      },
+    ]),
+    createSession("b", "Deploy", [
+      {
+        role: "user",
+        content: "please summarize",
+        attachments: [
+          { base64Data: "", mediaType: "text/plain", filename: "k8s-manifest.yaml" },
+          { base64Data: "", mediaType: "text/markdown", vaultNoteTitle: "Postgres runbook" },
+        ],
+      },
+    ]),
+    createSession("c", "Legacy", [
+      {
+        role: "user",
+        content: "see attached",
+        images: [
+          { base64Data: "", mediaType: "image/png", filename: "screenshot.png" },
+        ],
+      },
+    ]),
+    createSession("d", "Payloads", [
+      {
+        role: "user",
+        content: "",
+        attachments: [
+          { base64Data: "AAAA", mediaType: "image/png", terminalSelection: true },
+        ],
+      },
+    ]),
+  ];
+
+  assert.deepEqual(filterSessionHistory(sessions, "rate limit exceeded"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "k8s-manifest"), [sessions[1]]);
+  assert.deepEqual(filterSessionHistory(sessions, "postgres runbook"), [sessions[1]]);
+  assert.deepEqual(filterSessionHistory(sessions, "screenshot.png"), [sessions[2]]);
+  // Attachment base64 payloads and unlabeled attachments are not indexed.
+  assert.deepEqual(filterSessionHistory(sessions, "AAAA"), []);
+  assert.deepEqual(filterSessionHistory(sessions, "nothing here"), []);
+
+  const fields = collectSessionSearchFields(sessions[1]);
+  assert.ok(fields.some((field) => field.includes("k8s-manifest.yaml")));
+  assert.ok(fields.some((field) => field.includes("Postgres runbook")));
+  assert.ok(!fields.some((field) => field === "AAAA"));
+});
+
+test("budget exhaustion inside a message keeps the newest tool calls searchable", () => {
+  // One assistant message bearing enough tool calls (each argument capped at
+  // 2,000 chars) to exhaust the remaining session budget: iteration must be
+  // newest-first so the latest calls (appended at the array end) stay
+  // searchable instead of the oldest ones winning the budget.
+  const session = createSession("a", "Ops", [
+    {
+      role: "assistant",
+      content: "y".repeat(20_000),
+      toolCalls: Array.from({ length: 25 }, (_, i) => ({
+        name: `call-${i}`,
+        id: `t${i}`,
+        arguments: { command: `marker-args-${i} ${"z".repeat(20_000)}` },
+      })),
+    },
+  ]);
+
+  const fields = collectSessionSearchFields(session);
+  // The newest call (index 24, appended last) stays searchable along with the
+  // rest of the recent burst; the oldest call is the one dropped.
+  assert.ok(fields.some((field) => field.includes("marker-args-24")));
+  assert.ok(fields.some((field) => field.includes("marker-args-19")));
+  assert.ok(!fields.some((field) => field.includes("marker-args-0")));
+  assert.deepEqual(filterSessionHistory([session], "marker-args-24"), [session]);
+  // Retained call fields are output in chronological order after the
+  // newest-first collection is reversed back (call-10 before call-19).
+  const call10 = fields.findIndex((field) => field.includes("call-10"));
+  const call19 = fields.findIndex((field) => field.includes("call-19"));
+  assert.ok(call10 !== -1 && call19 !== -1 && call10 < call19);
+});
+
+test("later attachment labels stay searchable when the label list overflows the cap", () => {
+  // The joined labels of these attachments exceed the 2,000-character field
+  // cap; feeding labels individually keeps the later (newest) ones findable.
+  const session = createSession("a", "Deploy", [
+    {
+      role: "user",
+      content: "please summarize",
+      attachments: [
+        { base64Data: "", mediaType: "text/plain", filename: `pad-${"a".repeat(2_100)}` },
+        { base64Data: "", mediaType: "text/markdown", filename: "latest-run.log" },
+      ],
+    },
+  ]);
+
+  const fields = collectSessionSearchFields(session);
+  assert.ok(fields.some((field) => field.includes("latest-run.log")));
+  assert.deepEqual(filterSessionHistory([session], "latest-run"), [session]);
+});
+
+test("collectSessionSearchFields skips empty content and caps very long fields", () => {
+  const session = createSession("a", "  ", [
+    { role: "user", content: "   " },
+    { role: "assistant", content: "x".repeat(25_000) },
+  ]);
+
+  const fields = collectSessionSearchFields(session);
+  assert.equal(fields.length, 1);
+  assert.equal(fields[0].length, 20_000);
+});
+
+test("filterSessionHistory matches CJK titles via the shared pinyin matcher", () => {
+  const sessions = [
+    createSession("a", "重启生产服务器", []),
+    createSession("b", "backup", []),
+  ];
+
+  assert.deepEqual(filterSessionHistory(sessions, "chongqi"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "重启"), [sessions[0]]);
+});
+
+test("filterSessionHistory indexes the displayed fallback for untitled sessions", () => {
+  // An empty persisted title is displayed as the localized "Untitled" label;
+  // searching for that label must find the session instead of hiding it.
+  const sessions = [
+    createSession("a", "", [{ content: "nginx notes" }]),
+    createSession("b", "nginx restart", []),
+  ];
+
+  // Without the fallback the blank title contributes nothing.
+  assert.deepEqual(filterSessionHistory(sessions, "untitled"), []);
+  assert.deepEqual(filterSessionHistory(sessions, "untitled", { untitledLabel: "Untitled" }), [sessions[0]]);
+  // Titled sessions are unaffected by the fallback label.
+  assert.deepEqual(filterSessionHistory(sessions, "restart"), [sessions[1]]);
+  // Localized (CJK) fallback labels match through title pinyin too.
+  assert.deepEqual(filterSessionHistory(sessions, "无标题", { untitledLabel: "无标题" }), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "wbt", { untitledLabel: "无标题" }), [sessions[0]]);
+
+  const fields = collectSessionSearchFields(sessions[0], "Untitled");
+  assert.deepEqual(fields, ["Untitled", "nginx notes"]);
+});
+
+test("filterSessionHistory lets tokens span title pinyin and message text", () => {
+  const sessions = [
+    createSession("a", "重启服务器", [
+      { role: "user", content: "restarted nginx without errors" },
+    ]),
+  ];
+
+  const combined = filterSessionHistory(sessions, "chongqi nginx");
+  assert.deepEqual(combined, [sessions[0]]);
+  // Message-only pinyin still stays out of the expensive fallback.
+  assert.deepEqual(filterSessionHistory(sessions, "chongqi"), [sessions[0]]);
+  assert.deepEqual(
+    filterSessionHistory(sessions, "failing nginx"),
+    [],
+  );
+});
+
+test("search field trimming stays inside the field and remaining session limits", () => {
+  const fieldLimited = createSession("a", "Ops", [
+    { content: " ".repeat(20_000) + "outside-field" },
+    { content: "  recent-match  " + " ".repeat(1_000_000) },
+  ]);
+  assert.deepEqual(collectSessionSearchFields(fieldLimited), ["Ops", "recent-match"]);
+  assert.deepEqual(filterSessionHistory([fieldLimited], "recent-match"), [fieldLimited]);
+  assert.deepEqual(filterSessionHistory([fieldLimited], "outside-field"), []);
+
+  // Title + three full fields leave 3,997 characters for the oldest message.
+  // Trimming must not reach past that window to discover more content.
+  const sessionLimited = createSession("b", "Ops", [
+    { content: " ".repeat(3_997) + "outside-session" },
+    ...Array.from({ length: 3 }, () => ({ content: "x".repeat(20_000) })),
+  ]);
+  assert.equal(collectSessionSearchFields(sessionLimited).join("").length, 60_003);
+  assert.deepEqual(filterSessionHistory([sessionLimited], "outside-session"), []);
+});
+
+test("filterSessionHistory keeps the pinyin fallback on titles only", () => {
+  const sessions = [
+    createSession("a", "Ops", [
+      { role: "user", content: "重启生产服务器" },
+    ]),
+  ];
+
+  // Pinyin transliteration of long message content is skipped; literal CJK
+  // queries still match message text.
+  assert.deepEqual(filterSessionHistory(sessions, "重启"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "chongqi"), []);
+});
+
+test("collectSessionSearchFields bounds the total searchable text per session", () => {
+  const session = createSession("a", "big session", Array.from({ length: 40 }, (_, i) => ({
+    role: "user" as const,
+    content: `chunk-${i}-${"y".repeat(19_000)}`,
+  })));
+
+  const fields = collectSessionSearchFields(session);
+  const total = fields.reduce((sum, field) => sum + field.length, 0);
+  assert.ok(total <= 64_000, `total ${total} exceeds session cap`);
+  // Title is indexed first so it always lands in the bounded window.
+  assert.equal(fields[0], "big session");
+});
+
+test("collectSessionSearchFields keeps recent messages searchable under the cap", () => {
+  // Four 20,000-char messages exceed the 64 KB cap; the budget must be
+  // allocated newest-first so the most recent message remains searchable.
+  const session = createSession("a", "big session", [0, 1, 2, 3].map((i) => ({
+    role: "user" as const,
+    content: `${"x".repeat(19_900)} marker-${i}`,
+  })));
+
+  const fields = collectSessionSearchFields(session);
+  assert.equal(fields[0], "big session");
+  // Oldest messages are dropped, the newest is retained.
+  assert.ok(!fields.some((field) => field.includes("marker-0")));
+  assert.ok(fields.some((field) => field.includes("marker-3")));
+  // Output order stays chronological (marker-1 before marker-2).
+  const marker1 = fields.findIndex((field) => field.includes("marker-1"));
+  const marker2 = fields.findIndex((field) => field.includes("marker-2"));
+  assert.ok(marker1 !== -1 && marker2 !== -1 && marker1 < marker2);
+});
+
+test("collectSessionSearchFields truncates a field to the remaining session budget", () => {
+  // Four 19,000-char messages plus the title overflow the 64 KB cap; the last
+  // collected (oldest) message must be truncated to exactly the remaining
+  // budget instead of being discarded wholesale.
+  const session = createSession("a", "big session", [0, 1, 2, 3].map(() => ({
+    role: "user" as const,
+    content: "a".repeat(19_000),
+  })));
+
+  const fields = collectSessionSearchFields(session);
+  const total = fields.reduce((sum, field) => sum + field.length, 0);
+  assert.ok(total <= 64_000, `total ${total} exceeds session cap`);
+  assert.equal(total, 64_000);
+  // The oldest message fills the leftover budget with its freshest-available
+  // head instead of being dropped entirely.
+  assert.ok(fields.some((field) => field.length === 64_000 - (11 + 3 * 19_000)));
+  assert.ok(fields.some((field) => field.startsWith("aaa")));
+});
+
+test("huge tool call arguments are serialized within the field cap without full materialization", () => {
+  const blob = "x".repeat(5_000_000);
+  const sessions = [
+    createSession("a", "Ops", [
+      {
+        role: "assistant",
+        toolCalls: [{
+          // Retained calls can carry uncapped payloads (e.g. `sftp_write_file`
+          // content); serialization must stop at the field cap instead of
+          // stringifying the whole argument object on every keystroke.
+          name: "sftp_write_file",
+          id: "t1",
+          arguments: { path: "/tmp/report.md", content: blob },
+        }],
+      },
+    ]),
+  ];
+
+  const fields = collectSessionSearchFields(sessions[0]);
+  const serialized = fields.find((field) => field.includes("/tmp/report.md"));
+  assert.ok(serialized);
+  // The serialized field (plus the tool name) must land under the total
+  // per-session budget cap, i.e. no multi-megabyte field is ever emitted.
+  assert.ok(serialized!.length <= 2_000);
+  assert.ok(serialized!.includes("/tmp/report.md"));
+
+  // Short payloads still serialize fully and stay searchable.
+  const searchable = createSession("b", "Ops", [
+    {
+      role: "assistant",
+      toolCalls: [{
+        name: "shell",
+        id: "t2",
+        arguments: { command: "systemctl restart nginx" },
+      }],
+    },
+  ]);
+  assert.ok(
+    collectSessionSearchFields(searchable).some((field) => field.includes('"command":"systemctl restart nginx"')),
+  );
+});
+
+test("wide tool call argument objects and long property names stay within the cap", () => {
+  // A wide object: thousands of own properties must be iterated lazily
+  // instead of materializing the full entries array on every keystroke.
+  const wide: Record<string, unknown> = {};
+  for (let i = 0; i < 5_000; i++) wide[`key-${i}`] = `value-${i}`;
+  // An unusually large property name must be capped before it is escaped.
+  const longKey = "k".repeat(50_000);
+  const sessions = [
+    createSession("a", "Ops", [
+      {
+        role: "assistant",
+        toolCalls: [{
+          name: "shell",
+          id: "t1",
+          arguments: { command: "systemctl restart nginx", [longKey]: "ignored", ...wide },
+        }],
+      },
+    ]),
+  ];
+
+  const fields = collectSessionSearchFields(sessions[0]);
+  const serialized = fields.find((field) => field.includes("systemctl restart nginx"));
+  assert.ok(serialized);
+  assert.ok(serialized!.length <= 2_000);
+  // The oversized key (and the wide object past the cap) never materialize:
+  // the long key is truncated before escaping.
+  assert.ok(!fields.some((field) => field.length > 2_000));
+});
+
+test("filterSessionHistory matches persisted status text", () => {
+  const sessions = [
+    createSession("a", "Untitled", [
+      { role: "assistant", content: "", statusText: "generating diff for src/main.ts" },
+    ]),
+    createSession("b", "Deploy", [
+      { role: "user", content: "ship it" },
+    ]),
+  ];
+
+  assert.deepEqual(filterSessionHistory(sessions, "generating diff"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "src/main.ts"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "nothing here"), []);
+
+  const fields = collectSessionSearchFields(sessions[0]);
+  assert.ok(fields.some((field) => field.includes("generating diff for src/main.ts")));
+});
+
+// Regression: bounds enforcement must run once per scan, not on every cache
+// miss. Evicting per miss makes each rebuild drop the index of a later
+// session in the same scan, so any history longer than the entry cap
+// cycle-evicts the whole cache and rebuilds every corpus on every keystroke.
+test("filterSessionHistory keeps index-cache hits for histories larger than the cache cap", () => {
+  const sessionCount = 80;
+  const sessions = Array.from({ length: sessionCount }, (_, i) =>
+    createSession(`s${i}`, `session ${i}`, [{ content: `body ${i} deploy` }]));
+  // Observe corpus (re)builds: a cache hit serves the prepared haystack
+  // without touching `messages`, while a rebuild collects the fields again.
+  const readSessions = new Set<string>();
+  for (const session of sessions) {
+    const messages = session.messages;
+    Object.defineProperty(session, "messages", {
+      get() {
+        readSessions.add(session.id);
+        return messages;
+      },
+      configurable: true,
+    });
+  }
+
+  filterSessionHistory(sessions, "deploy");
+  readSessions.clear();
+  const second = filterSessionHistory(sessions, "deploy");
+
+  // End-of-scan eviction only prunes the per-scan overshoot: the indexes of
+  // every session retained by the last prune are cache hits. Per-miss
+  // eviction would have rebuilt all 80 sessions here.
+  const rebuilt = readSessions.size;
+  assert.ok(rebuilt <= sessionCount - 64, `expected no cache thrash, rebuilt ${rebuilt}`);
+  assert.deepEqual(second, sessions);
+  // Eviction must retain the FRONT of the ranked list (the sessions the next
+  // scan visits first) and rebuild only the oldest tail above the entry cap —
+  // evicting the Map's first key would drop the head and thrash it instead.
+  const rebuiltIds = [...readSessions].sort();
+  assert.deepEqual(
+    rebuiltIds,
+    sessions.slice(-(sessionCount - 64)).map((s) => s.id).sort(),
+  );
+});
+
+// Regression: hard-rejecting NEW entries once the entry cap is saturated by
+// live sessions froze the cache's membership. New sessions are prepended to
+// the ranked list, so every subsequently created conversation (and its
+// immutable streaming updates) would rebuild its index on every keystroke
+// while stale lower-ranked entries stayed cached — and the end-of-scan prune
+// could not correct it because the cache was already within both bounds.
+test("filterSessionHistory admits a newly created session after the entry cap is saturated", () => {
+  const initial = Array.from({ length: 64 }, (_, i) =>
+    createSession(`s${i}`, `session ${i}`, [{ content: `body ${i} deploy` }]));
+  filterSessionHistory(initial, "deploy");
+
+  // A newly created session is prepended: it ranks above every cached entry.
+  const created = createSession("fresh", "fresh session", [{ content: "body fresh deploy" }]);
+  const sessions = [created, ...initial];
+
+  // Observe corpus (re)builds as in the thrash regression test above.
+  const readSessions = new Set<string>();
+  for (const session of sessions) {
+    const messages = session.messages;
+    Object.defineProperty(session, "messages", {
+      get() {
+        readSessions.add(session.id);
+        return messages;
+      },
+      configurable: true,
+    });
+  }
+
+  // First scan over the new list: "fresh" misses (its index was never cached)
+  // and must be admitted; the prune evicts the lowest-ranked tail instead.
+  filterSessionHistory(sessions, "deploy");
+  readSessions.clear();
+  const third = filterSessionHistory(sessions, "deploy");
+
+  assert.deepEqual(third, sessions);
+  // The fresh, highest-ranked session stays cached; only the evicted tail
+  // above the entry cap is rebuilt.
+  assert.ok(!readSessions.has("fresh"), `expected fresh session to be cached, rebuilt: ${[...readSessions]}`);
+  assert.deepEqual([...readSessions], ["s63"]);
+});
+
+// Regression: the entry cap must be enforced at cache-admission time, not only
+// by the end-of-scan prune. When misses are small (empty/short searchable
+// content), the char budget consumes almost no headroom per insert, so
+// overshooting the entry cap mid-scan and letting the prune trim it made a
+// single keystroke over a very long history build and transiently retain one
+// index + Map entry per live session. Admission must instead evict the stale
+// lowest-ranked untouched tail to make room (the same entry the prune would
+// otherwise drop moments later), keeping the cache within the entry cap
+// throughout the scan.
+test("filterSessionHistory evicts the stale tail at admission instead of overshooting the entry cap", () => {
+  const initial = Array.from({ length: 64 }, (_, i) =>
+    createSession(`s${i}`, `session ${i}`, [{ content: `body ${i} deploy` }]));
+  filterSessionHistory(initial, "deploy");
+
+  // A newly created session is prepended: it ranks above every cached entry.
+  const created = createSession("fresh", "fresh session", [{ content: "body fresh deploy" }]);
+  const sessions = [created, ...initial];
+
+  // Observe corpus (re)builds as in the regression tests above.
+  const readSessions = new Set<string>();
+  for (const session of sessions) {
+    const messages = session.messages;
+    Object.defineProperty(session, "messages", {
+      get() {
+        readSessions.add(session.id);
+        return messages;
+      },
+      configurable: true,
+    });
+  }
+
+  // The single scan over the prepended list must admit "fresh" by evicting
+  // the stalest cached tail entry ("s63") during the scan: under the old
+  // overshoot-then-prune behavior "s63" would stay cached until the prune,
+  // so it would not be rebuilt in this same scan at all. Rebuilding it here
+  // is the (bounded, one-entry) cost of never exceeding the entry cap
+  // mid-scan.
+  filterSessionHistory(sessions, "deploy");
+  assert.deepEqual([...readSessions].sort(), ["fresh", "s63"]);
+
+  // Recovery is unchanged: the fresh session stays cached, and only the
+  // tail displaced below the entry cap rebuilds on the next keystroke.
+  readSessions.clear();
+  const next = filterSessionHistory(sessions, "deploy");
+  assert.deepEqual(next, sessions);
+  assert.ok(!readSessions.has("fresh"), `expected fresh session to be cached, rebuilt: ${[...readSessions]}`);
+  assert.deepEqual([...readSessions], ["s63"]);
+});
+
+// Regression: a hard-reject at the CHAR-budget gate froze cache membership
+// just like the earlier entry-cap bug. With ~20 large sessions (each near the
+// 64,000-character corpus cap) already consuming nearly the 4M-character
+// cache budget, a newly prepended high-ranked session was rejected without
+// evicting anything, and the end-of-scan prune — seeing a cache within both
+// bounds — kept the stale lower-ranked entries: the new large conversation
+// then rebuilt its index on every search keystroke.
+test("filterSessionHistory admits a newly created session after the char budget is saturated", () => {
+  // Corpus exactly 64,000 chars (title + 4 x 15,999-char messages), each
+  // index retaining ~192K chars (normalized fields + haystack + compact
+  // haystack): 20 fill ~3.84M of the 4M budget; a 21st would overflow it.
+  const createLargeSession = (id: string) =>
+    createSession(id, "sess", [0, 1, 2, 3].map(() => ({ content: "x".repeat(15_999) })));
+
+  const initial = Array.from({ length: 20 }, (_, i) => createLargeSession(`s${i}`));
+  filterSessionHistory(initial, "x");
+
+  // A newly created large session is prepended: it ranks above every cached
+  // entry, and its index can only fit if the stale tail is evicted.
+  const created = createLargeSession("fresh");
+  const sessions = [created, ...initial];
+
+  // Observe corpus (re)builds as in the regression tests above.
+  const readSessions = new Set<string>();
+  for (const session of sessions) {
+    const messages = session.messages;
+    Object.defineProperty(session, "messages", {
+      get() {
+        readSessions.add(session.id);
+        return messages;
+      },
+      configurable: true,
+    });
+  }
+
+  // First scan over the new list: "fresh" misses (its index was never cached)
+  // and must be admitted by evicting the stalest cached tail entry.
+  filterSessionHistory(sessions, "x");
+  readSessions.clear();
+  const second = filterSessionHistory(sessions, "x");
+
+  assert.deepEqual(second, sessions);
+  // The fresh, highest-ranked session stays cached; only the evicted stalest
+  // tail session (which no longer fits the char budget) rebuilds.
+  assert.ok(!readSessions.has("fresh"), `expected fresh session to be cached, rebuilt: ${[...readSessions]}`);
+  assert.deepEqual([...readSessions], ["s19"]);
+  // And the steady state holds on subsequent scans too.
+  readSessions.clear();
+  filterSessionHistory(sessions, "x");
+  assert.deepEqual([...readSessions], ["s19"]);
+});
+
+test("filterSessionHistory blank-query path prunes cache entries for sessions that left the list", () => {
+  const kept = createSession("keep", "nginx restart", [{ content: "reload nginx" }]);
+  const removed = createSession("remove", "disk cleanup", [{ content: "rm old logs" }]);
+
+  filterSessionHistory([kept, removed], "nginx");
+  // Deleting a session then clearing the query goes through the blank path,
+  // which must prune the cache against the remaining list.
+  filterSessionHistory([kept], "");
+  // Subsequent searches are unaffected: the surviving session stays cached
+  // (its cached index is still there) and matching still works.
+  assert.deepEqual(filterSessionHistory([kept], "nginx"), [kept]);
+  assert.deepEqual(filterSessionHistory([kept], "nothing here"), []);
+  // The removed session's index is gone entirely (no match via a stale cache).
+  assert.deepEqual(filterSessionHistory([kept, removed], "rm old logs"), [removed]);
+});
+
+test("clearSessionHistorySearchCache releases cached indexes without breaking later searches", () => {
+  const session = createSession("a", "nginx restart", [{ content: "reload nginx" }]);
+
+  filterSessionHistory([session], "nginx");
+  clearSessionHistorySearchCache();
+  // After the clear, the next search rebuilds from scratch and still matches.
+  assert.deepEqual(filterSessionHistory([session], "nginx"), [session]);
+  assert.deepEqual(filterSessionHistory([session], ""), [session]);
+});
+
+test("independent search instances own isolated caches", () => {
+  const first = createSessionHistorySearch();
+  const second = createSessionHistorySearch();
+  const session = createSession("iso-1", "isolated cache", [{ content: "lighthouse" }]);
+  assert.deepEqual(first.filterSessionHistory([session], "lighthouse"), [session]);
+  // Clearing one instance must not disturb the other's state: both stay fully
+  // functional afterwards (each store is private to its instance).
+  second.clearSessionHistorySearchCache();
+  assert.deepEqual(second.filterSessionHistory([session], "lighthouse"), [session]);
+  assert.deepEqual(first.filterSessionHistory([session], "lighthouse"), [session]);
+});
+
+test("filterSessionHistory caps the query and matches on its capped prefix", () => {
+  const session = createSession("a", "nginx restart", [{ content: "reload nginx" }]);
+
+  // A pasted multi-megabyte query must not be re-normalized per session: it is
+  // capped via truncateQueryForMatch (MAX_SEARCH_QUERY_LENGTH) at this scan's
+  // input and normalized once per scan, so matching falls back to the capped
+  // prefix (which still spans tokens here).
+  const longQuery = `${"nginx ".repeat(200_000)}zzz-impossible-tail`;
+  assert.deepEqual(filterSessionHistory([session], longQuery), [session]);
+  // The uncapped-looking but normal query still matches exactly.
+  assert.deepEqual(filterSessionHistory([session], "zzz-impossible-tail"), []);
+});
+
+// Keep the author's long-title rescan protection local to history. Shared
+// search must still match complete fields, including later joined fields.
+test("history pinyin cache preserves long titles across same-order rescans", () => {
+  resetPinyinCacheForTests();
+  const sessions = Array.from({ length: 17 }, (_, index) =>
+    createSession(`rescan-${index}`, `标题${index}${"重启".repeat(10_000)}`, []));
+  for (let pass = 0; pass < 2; pass += 1) {
+    assert.deepEqual(filterSessionHistory(sessions, "unmatched-latin"), []);
+  }
+  const stats = getPinyinCacheStatsForTests();
+  assert.equal(stats.size, sessions.length);
+  assert.ok(stats.chars <= PINYIN_CACHE_MAX_CHARS);
+  resetPinyinCacheForTests();
+});
+
+test("history alone bounds title pinyin while retaining literal title and body matches", () => {
+  const sessions = [
+    createSession("pinyin-head", `服务器${"a".repeat(256)}`, [{ content: "nginx" }]),
+    createSession("pinyin-tail", `${"a".repeat(256)}服务器`, [{ content: "nginx" }]),
+  ];
+  assert.deepEqual(filterSessionHistory(sessions, "fuwuqi nginx"), [sessions[0]]);
+  assert.deepEqual(filterSessionHistory(sessions, "服务器 nginx"), sessions);
+});

application/state/sessionHistorySearch.ts

@@ -0,0 +1,382 @@
+import {
+  getSessionSearchTitle,
+  matchesSessionSearchIndex,
+  prepareSessionSearchIndex,
+  type SessionHistorySearchTarget,
+  type SessionSearchIndex,
+} from '../../domain/sessionHistorySearch';
+import { prepareSearchQuery, truncateQueryForMatch } from '../../lib/searchMatcher';
+
+/**
+ * Memory bounds for the per-session search index cache. `filterSessionHistory`
+ * runs on every search keystroke, but `pruneSessionsForStorage` only bounds the
+ * persisted copy — `useAIState` retains hundreds of live sessions in memory,
+ * and rebuilding plus re-normalizing each session's (up to 64,000-character)
+ * haystack per keystroke scans tens of megabytes and freezes the renderer.
+ *
+ * The raw collected fields are NOT retained (only the prepared search fields),
+ * and
+ * the cache holds at most `MAX_SESSION_SEARCH_INDEX_CACHE_ENTRIES` entries
+ * within a `MAX_SESSION_SEARCH_INDEX_CACHE_CHARS` character budget: an
+ * unbounded cache would let one entry per live session (several normalized
+ * copies of each session's searchable corpus) permanently pin hundreds of
+ * megabytes in a long-running process. Both bounds hold after every scan's
+ * prune and are enforced eagerly on every insert (see
+ * `canCacheSessionSearchIndex`): when either bound lacks headroom, the gate
+ * first evicts the cache's stale, lowest-ranked untouched tail (entries the
+ * in-flight scan has not yet visited — they rank below every visited session,
+ * so this can never cycle-evict an entry the same scan still needs); if no
+ * such entry remains, the insert is skipped — the miss is then rebuilt on the
+ * next search, exactly what the end-of-scan prune would have done to it.
+ * Skipping is only reachable for misses ranked below every cached entry, so
+ * cache membership never freezes for freshly prepended high-ranked sessions:
+ * at their (earliest) visit nothing is touched yet and the stale tail yields.
+ */
+const MAX_SESSION_SEARCH_INDEX_CACHE_ENTRIES = 64;
+const MAX_SESSION_SEARCH_INDEX_CACHE_CHARS = 4_000_000;
+
+/**
+ * Mutable cache state owned by exactly one search client (one mounted history
+ * drawer). Keeping this out of module scope means several concurrently mounted
+ * drawers (one per terminal tab) never share a cache: each drawer's prune only
+ * drops entries no longer in that drawer's scoped session list, and one
+ * drawer's unmount releases only its own store (previously a shared
+ * module-level cache was discarded for every drawer on any unmount and pruned
+ * against whichever drawer scanned last).
+ */
+export type SessionHistorySearchStore = {
+  /**
+   * Sessions in state are updated immutably (`{ ...s, messages: next }`), so
+   * object identity is a reliable cache key: each session's normalized/compact
+   * haystacks are built once and reused until that session's object changes.
+   * A changed display title (e.g. a localized fallback switch) forces a rebuild.
+   */
+  cache: Map<SessionHistorySearchTarget, SessionSearchIndex>;
+  /**
+   * Session keys the in-flight `filterSessionHistory` scan has already visited
+   * (re-appended cache hits or inserted misses). `canCacheSessionSearchIndex`
+   * never evicts a touched key: it either ranks above the current insert (it was
+   * visited earlier in this newest-first scan) or it is the current session
+   * itself (whose stale entry a rebuild is about to replace), and evicting either
+   * would cycle-evict entries the same scan still needs.
+   */
+  scanTouched: Set<SessionHistorySearchTarget>;
+  /**
+   * Running total of the cache's retained characters. Maintained at every
+   * mutation site so the eager insert gate in `canCacheSessionSearchIndex` stays
+   * O(1) per miss instead of re-summing the whole cache on every keystroke
+   * (mid-scan overshoot of the entry cap would otherwise make that sum O(n²)
+   * across a scan).
+   */
+  cacheChars: number;
+};
+
+/** Retained characters of an index (the prepared haystacks; raw fields are dropped). */
+function indexRetainedChars(index: SessionSearchIndex): number {
+  // `normalizedFields`, `haystack` and `haystackCompact` are all retained
+  // (`haystack` is `normalizedFields` joined, `haystackCompact` is derived
+  // from `haystack`), so their combined length approximates the cache's
+  // per-entry memory cost. Counting only the joined haystacks would
+  // undercount by roughly a full copy of the corpus and let the char budget
+  // retain ~50% more than advertised.
+  let total = index.prepared.haystack.length + index.prepared.haystackCompact.length;
+  for (const field of index.prepared.normalizedFields) total += field.length;
+  return total;
+}
+
+/**
+ * Whether a freshly built index may be inserted into the cache without
+ * pushing either bound past its cap. Both bounds must fit eagerly — the prune
+ * that re-enforces them runs once per scan, so admitting every prepared index
+ * would let a single search over hundreds/thousands of uncached sessions
+ * transiently pin the whole corpus (several normalized haystacks per session)
+ * or hold one index and Map entry per live session — for empty/short sessions
+ * the char budget consumes little room, so the entry cap would be enforced
+ * only after the complete scan — before pruning, briefly allocating memory
+ * for the whole scanned list.
+ *
+ * Rather than rejecting inserts outright (which froze cache membership the
+ * same way a hard entry-count gate would), lack of headroom in either bound
+ * first evicts the cache's stale tail — the lowest-ranked entries this scan
+ * has not yet visited. Because the scan visits the ranked list newest-first,
+ * every untouched entry ranks below the current insert, so evicting any of
+ * them never drops an index a later visit of the same scan still needs (no
+ * cycle thrash) and always preserves the highest-ranked cached prefix. Only
+ * if no untouched entry remains does the insert get skipped — that is
+ * reachable only for misses ranked below every cached entry, which the
+ * end-of-scan prune would have evicted from the Map's back anyway, so the
+ * skip changes no steady-state membership: the index is simply rebuilt on
+ * the next search.
+ *
+ * The bounds check is applied to NEW entries only: cache hits merely
+ * re-append an existing entry (no growth), and a rebuild replaces the same
+ * session's entry (no entry-count growth; the char delta against the
+ * replaced index is checked).
+ */
+function canCacheSessionSearchIndex(
+  store: SessionHistorySearchStore,
+  previous: SessionSearchIndex | undefined,
+  index: SessionSearchIndex,
+): boolean {
+  const deltaChars = indexRetainedChars(index) - (previous ? indexRetainedChars(previous) : 0);
+  // A rebuild replaces its own entry (no entry-count growth); a new entry
+  // grows the Map by one.
+  const growsEntries = !previous;
+  if (
+    deltaChars <= 0
+    && (!growsEntries || store.cache.size < MAX_SESSION_SEARCH_INDEX_CACHE_ENTRIES)
+  ) {
+    return true;
+  }
+  if (
+    store.cacheChars + deltaChars <= MAX_SESSION_SEARCH_INDEX_CACHE_CHARS
+    && (!growsEntries || store.cache.size < MAX_SESSION_SEARCH_INDEX_CACHE_ENTRIES)
+  ) {
+    return true;
+  }
+  // Not enough headroom: evict the lowest-ranked untouched entries. Mid-scan
+  // the Map's order is old-insertion-order front to back with this scan's
+  // touched keys re-appended at the end, so scanning the keys back-to-front
+  // and skipping touched ones reaches the untouched (stalest, lowest-ranked)
+  // entries first.
+  let entriesToFree = growsEntries
+    ? store.cache.size + 1 - MAX_SESSION_SEARCH_INDEX_CACHE_ENTRIES
+    : 0;
+  const keysInInsertionOrder = [...store.cache.keys()];
+  for (let i = keysInInsertionOrder.length - 1; i >= 0; i--) {
+    if (entriesToFree <= 0
+      && store.cacheChars + deltaChars <= MAX_SESSION_SEARCH_INDEX_CACHE_CHARS) {
+      break;
+    }
+    const key = keysInInsertionOrder[i];
+    if (store.scanTouched.has(key)) continue;
+    const evicted = store.cache.get(key);
+    if (!evicted) continue;
+    store.cacheChars -= indexRetainedChars(evicted);
+    store.cache.delete(key);
+    if (growsEntries) entriesToFree--;
+  }
+  return store.cacheChars + deltaChars <= MAX_SESSION_SEARCH_INDEX_CACHE_CHARS
+    && (!growsEntries || store.cache.size < MAX_SESSION_SEARCH_INDEX_CACHE_ENTRIES);
+}
+
+function getSessionSearchIndex(
+  store: SessionHistorySearchStore,
+  session: SessionHistorySearchTarget,
+  untitledLabel: string,
+): SessionSearchIndex {
+  const indexedTitle = getSessionSearchTitle(session, untitledLabel);
+  const cached = store.cache.get(session);
+  if (cached && cached.displayTitle === indexedTitle) {
+    // Re-append on every visit so the cache's insertion order mirrors the
+    // latest scan's visitation order (the ranked, newest-first session list);
+    // `pruneSessionSearchIndexCache` relies on that order when evicting.
+    store.cache.delete(session);
+    store.cache.set(session, cached);
+    store.scanTouched.add(session);
+    return cached;
+  }
+  const index = prepareSessionSearchIndex(session, untitledLabel);
+  // Mark the session touched before the gate so the gate's admission eviction
+  // can never pick this session's own (stale) entry — the rebuild below is
+  // about to replace it, and evicting it would corrupt the running char total.
+  store.scanTouched.add(session);
+  if (canCacheSessionSearchIndex(store, cached, index)) {
+    store.cache.set(session, index);
+    // Keep the eager gate's running total in sync (also covers the
+    // display-title-change rebuild, which replaces an existing entry).
+    store.cacheChars += indexRetainedChars(index) - (cached ? indexRetainedChars(cached) : 0);
+  }
+  return index;
+}
+
+/**
+ * Eviction runs once per full scan (at the end of `filterSessionHistory`), not
+ * on every cache miss: evicting during the scan would make each miss drop the
+ * index of a later session in the same scan, so any history longer than the
+ * entry cap would cycle-evict the whole cache and rebuild every session's
+ * haystack on every keystroke. Deferring eviction keeps every retained entry
+ * usable within a scan while still bounding the cache — first by dropping
+ * indexes for sessions no longer in the scanned list, then by evicting the
+ * lowest-ranked entries (the oldest tail of the newest-first ranked list)
+ * until both bounds hold, preserving the front of the ranked list.
+ *
+ * In practice the eviction loop is cheap: both bounds are enforced eagerly
+ * on every insert (see `canCacheSessionSearchIndex`), so the cache never
+ * overshoots the entry cap or char budget mid-scan — the prune only drops
+ * indexes for sessions that left the scanned list and re-syncs the running
+ * char total.
+ */
+function pruneSessionSearchIndexCache(
+  store: SessionHistorySearchStore,
+  sessions: readonly SessionHistorySearchTarget[],
+): void {
+  const live = new Set<SessionHistorySearchTarget>(sessions);
+  for (const key of [...store.cache.keys()]) {
+    if (!live.has(key)) store.cache.delete(key);
+  }
+  let retained = 0;
+  for (const cachedIndex of store.cache.values()) {
+    retained += indexRetainedChars(cachedIndex);
+  }
+  // Re-sync the eager gate's running total: the sum above is authoritative
+  // here (once per scan), so any drift accumulated mid-scan is corrected.
+  store.cacheChars = retained;
+  // Evict from the END of the Map until both bounds hold. Every scan visits
+  // the full ranked session list newest-first and `getSessionSearchIndex`
+  // re-appends each visited entry, so after a scan the Map's insertion order
+  // mirrors visitation order: the highest-ranked (newest) sessions sit at the
+  // FRONT and the oldest tail at the BACK. Evicting the front (classic LRU on
+  // Map order) would therefore drop the newest, highest-ranked sessions and
+  // retain the stalest tail — every subsequent keystroke would rebuild every
+  // session above the cache cap. Evicting the back instead preserves the
+  // front of the ranked list. The single remaining entry is always kept, even
+  // if it alone exceeds the char budget (a single entry is bounded by ~192K
+  // chars by the collector caps).
+  // Snapshot the keys once: prune only deletes (never inserts), so popping
+  // from this array visits keys exactly in Map order, back to front.
+  const keysInInsertionOrder = [...store.cache.keys()];
+  while (
+    store.cache.size > MAX_SESSION_SEARCH_INDEX_CACHE_ENTRIES
+    || retained > MAX_SESSION_SEARCH_INDEX_CACHE_CHARS
+  ) {
+    // A single entry can never push the cache past the char budget (it is
+    // bounded by ~192K chars by the collector caps), so keep the last entry.
+    if (store.cache.size <= 1) break;
+    const evictKey = keysInInsertionOrder.pop();
+    if (evictKey === undefined) break;
+    const evicted = store.cache.get(evictKey);
+    if (evicted) retained -= indexRetainedChars(evicted);
+    store.cache.delete(evictKey);
+  }
+  store.cacheChars = retained;
+}
+
+/**
+ * Release every cached index and touched-session reference for one store
+ * (invoked for the drawer's unmount lifecycle via the per-drawer search
+ * instance). Cache keys are the session objects themselves, so clearing fully
+ * drops all strong session references — the retained haystack characters
+ * become garbage together with their sessions.
+ */
+function clearSessionHistorySearchStore(store: SessionHistorySearchStore): void {
+  store.cache.clear();
+  store.scanTouched.clear();
+  store.cacheChars = 0;
+}
+
+export type SessionHistorySearchOptions = {
+  /**
+   * Localized fallback label rendered by the drawer for sessions with an
+   * empty persisted title (e.g. `t('ai.chat.untitled')`); indexed as the
+   * displayed title so searching for the visible label finds the session.
+   */
+  untitledLabel?: string;
+};
+
+function filterSessionHistoryStore<T extends SessionHistorySearchTarget>(
+  store: SessionHistorySearchStore,
+  sessions: readonly T[],
+  query: string,
+  options: SessionHistorySearchOptions = {},
+): T[] {
+  const trimmed = query.trim();
+  if (!trimmed) {
+    // The blank-query path skips the scan entirely; release any stale
+    // scan-touched state so it cannot pin visited sessions (and their
+    // message/attachment memory) while the drawer is open without a query.
+    // Normally this set is already empty — the nonblank scan clears it in its
+    // `finally` — but clearing here too keeps every entry path leak-free.
+    store.scanTouched.clear();
+    // Cache keys are the session objects themselves, so an entry for a
+    // deleted/replaced session strongly retains that session (and its full
+    // message/attachment payloads). Prune against the current list here too:
+    // the blank-query path may run while the drawer stays open after
+    // deletions, and a later nonblank search that would prune otherwise may
+    // never happen (e.g. the user just closes the drawer).
+    pruneSessionSearchIndexCache(store, sessions);
+    return [...sessions];
+  }
+  const untitledLabel = options.untitledLabel ?? '';
+  // Bound and prepare the query once per scan: a pasted-in multi-megabyte
+  // query would otherwise be re-normalized (NFKC), tokenized and compacted
+  // inside `matchesSessionSearchIndex` for every session, freezing the
+  // renderer. The cap (`truncateQueryForMatch`, `MAX_SEARCH_QUERY_LENGTH`) is
+  // applied here at this scan's input — not inside the shared `prepareSearchQuery`
+  // — so the meaning of over-limit queries stays local to session history and
+  // the normalized forms are computed a single time, letting the per-session
+  // work below only do `includes` scans over the cached haystacks.
+  const preparedQuery = prepareSearchQuery(truncateQueryForMatch(trimmed));
+  // A new scan starts with no visited sessions: the touched set records only
+  // this scan's visits so `canCacheSessionSearchIndex` can never mistake a
+  // previous scan's keys for keys the current scan still needs.
+  store.scanTouched.clear();
+  try {
+    // Drop entries still held by sessions that left the scan list (e.g. the
+    // history shrank or session objects changed since the previous scan). Those
+    // entries are never visited by this scan — the end-of-scan prune would
+    // remove them too — but dropping them up front keeps their characters
+    // available to this scan's inserts (via the eager char gate). Cheap: one
+    // Set plus one pass over the cached keys.
+    const currentLive = new Set<SessionHistorySearchTarget>(sessions);
+    for (const key of [...store.cache.keys()]) {
+      if (!currentLive.has(key)) {
+        const removed = store.cache.get(key);
+        if (removed) store.cacheChars -= indexRetainedChars(removed);
+        store.cache.delete(key);
+      }
+    }
+    // Scan all sessions first (a miss admits its index into the cache —
+    // evicting this scan's untouched stale tail whenever either bound lacks
+    // headroom, and skipping the insert only when no untouched entry remains),
+    // then prune entries that fell out of the scan list at the end of the
+    // scan.
+    const result = sessions.filter((session) => {
+      const index = getSessionSearchIndex(store, session, untitledLabel);
+      return matchesSessionSearchIndex(preparedQuery, index);
+    });
+    // Prune against the full scanned list (not the filtered result): sessions
+    // that merely did not match this query must keep their cached indexes.
+    pruneSessionSearchIndexCache(store, sessions);
+    return result;
+  } finally {
+    // The touched set only guards against cycle-eviction within the current
+    // scan; once the scan ends (even if it throws), release its strong
+    // references to session objects so deleted/replaced sessions and their
+    // large message/attachment payloads aren't retained until the next
+    // nonblank search.
+    store.scanTouched.clear();
+  }
+}
+
+/**
+ * One stateful search instance per consumer (one mounted session history
+ * drawer). The cache lives in the returned instance's store instead of module
+ * scope, so concurrently mounted drawers (one per terminal tab) never share
+ * state: an unmount of one drawer clears only that drawer's indexes, and each
+ * drawer's prune is scoped to its own session list.
+ */
+export type SessionHistorySearch = {
+  filterSessionHistory: <T extends SessionHistorySearchTarget>(
+    sessions: readonly T[],
+    query: string,
+    options?: SessionHistorySearchOptions,
+  ) => T[];
+  clearSessionHistorySearchCache: () => void;
+};
+
+export function createSessionHistorySearch(): SessionHistorySearch {
+  const store: SessionHistorySearchStore = {
+    cache: new Map(),
+    scanTouched: new Set(),
+    cacheChars: 0,
+  };
+  return {
+    filterSessionHistory(sessions, query, options = {}) {
+      return filterSessionHistoryStore(store, sessions, query, options);
+    },
+    clearSessionHistorySearchCache() {
+      clearSessionHistorySearchStore(store);
+    },
+  };
+}

application/state/settingsStateDefaults.test.ts

@@ -9,9 +9,14 @@ import {
   resolveReadableForegroundForHsl,
   resolveThemeAccentForeground,
   migrateIncomingTerminalFontId,
+  migrateMaterializedAutoCloseOnExitDefault,
 } from "./settingsStateDefaults.ts";
 import { TERMINAL_FONT_AUTO } from "../../infrastructure/config/fonts.ts";
-import { STORAGE_KEY_TERM_FONT_FAMILY } from "../../infrastructure/config/storageKeys.ts";
+import {
+  STORAGE_KEY_TERM_AUTO_CLOSE_EXIT_MIGRATED,
+  STORAGE_KEY_TERM_FONT_FAMILY,
+  STORAGE_KEY_TERM_SETTINGS,
+} from "../../infrastructure/config/storageKeys.ts";
 import type { UiThemeTokens } from "../../infrastructure/config/uiThemes.ts";
 
 function installMemoryLocalStorage(): Map<string, string> {
@@ -140,3 +145,72 @@ test("app surface theme vars isolate non-terminal pages from active terminal chr
     "--ring": "270 70% 45%",
   });
 });
+
+test("migrateMaterializedAutoCloseOnExitDefault resets the materialized default-on once", () => {
+  const store = installMemoryLocalStorage();
+  try {
+    store.set(
+      STORAGE_KEY_TERM_SETTINGS,
+      JSON.stringify({ scrollback: 3000, autoCloseOnExit: true }),
+    );
+    migrateMaterializedAutoCloseOnExitDefault();
+    const migrated = JSON.parse(store.get(STORAGE_KEY_TERM_SETTINGS)!);
+    assert.equal(migrated.autoCloseOnExit, false);
+    // Other saved settings pass through untouched.
+    assert.equal(migrated.scrollback, 3000);
+    assert.equal(store.get(STORAGE_KEY_TERM_AUTO_CLOSE_EXIT_MIGRATED), "true");
+  } finally {
+    delete (globalThis as { localStorage?: unknown }).localStorage;
+  }
+});
+
+test("migrateMaterializedAutoCloseOnExitDefault runs once and respects later explicit edits", () => {
+  const store = installMemoryLocalStorage();
+  try {
+    store.set(
+      STORAGE_KEY_TERM_SETTINGS,
+      JSON.stringify({ autoCloseOnExit: true }),
+    );
+    migrateMaterializedAutoCloseOnExitDefault();
+    assert.equal(
+      JSON.parse(store.get(STORAGE_KEY_TERM_SETTINGS)!).autoCloseOnExit,
+      false,
+    );
+    // The user re-enables after upgrading: the migration must not undo it again.
+    store.set(
+      STORAGE_KEY_TERM_SETTINGS,
+      JSON.stringify({ autoCloseOnExit: true }),
+    );
+    migrateMaterializedAutoCloseOnExitDefault();
+    assert.equal(
+      JSON.parse(store.get(STORAGE_KEY_TERM_SETTINGS)!).autoCloseOnExit,
+      true,
+    );
+  } finally {
+    delete (globalThis as { localStorage?: unknown }).localStorage;
+  }
+});
+
+test("migrateMaterializedAutoCloseOnExitDefault leaves fresh installs and explicit-off alone", () => {
+  const store = installMemoryLocalStorage();
+  try {
+    // Fresh install: no saved settings at all.
+    migrateMaterializedAutoCloseOnExitDefault();
+    assert.equal(store.has(STORAGE_KEY_TERM_SETTINGS), false);
+    assert.equal(store.get(STORAGE_KEY_TERM_AUTO_CLOSE_EXIT_MIGRATED), "true");
+
+    // Explicit-off (or any settings blob without the key) is never rewritten.
+    delete (globalThis as { localStorage?: unknown }).localStorage;
+    const store2 = installMemoryLocalStorage();
+    store2.set(
+      STORAGE_KEY_TERM_SETTINGS,
+      JSON.stringify({ scrollback: 500 }),
+    );
+    migrateMaterializedAutoCloseOnExitDefault();
+    assert.deepEqual(JSON.parse(store2.get(STORAGE_KEY_TERM_SETTINGS)!), {
+      scrollback: 500,
+    });
+  } finally {
+    delete (globalThis as { localStorage?: unknown }).localStorage;
+  }
+});

application/state/settingsStateDefaults.ts

@@ -1,5 +1,9 @@
 import type { HotkeyScheme, SessionLogFormat, TerminalSettings } from '../../domain/models';
-import { STORAGE_KEY_TERM_FONT_FAMILY } from '../../infrastructure/config/storageKeys';
+import {
+  STORAGE_KEY_TERM_AUTO_CLOSE_EXIT_MIGRATED,
+  STORAGE_KEY_TERM_FONT_FAMILY,
+  STORAGE_KEY_TERM_SETTINGS,
+} from '../../infrastructure/config/storageKeys';
 import {
   isDeprecatedPrimaryFontId,
   TERMINAL_FONT_AUTO,
@@ -63,6 +67,30 @@ export function migrateIncomingTerminalFontId(raw: string | null | undefined): s
   }
   return raw;
 }
+/**
+ * One-time migration for the autoCloseOnExit default flip (tabs now survive
+ * session exits by default; the old default-on silently deleted tabs whenever
+ * a bastion or idle-harvesting server reported a clean exit). Builds before
+ * the flip shipped autoCloseOnExit: true as the default and materialized it
+ * into STORAGE_KEY_TERM_SETTINGS on any settings write, so most upgraders
+ * carry a value they never chose. Leaving it in place would make the new
+ * default unreachable for them. Reset that materialized `true` exactly once
+ * and persist the marker; afterwards every stored value is treated as the
+ * user's own choice and is respected. An inbound cloud or backup payload that
+ * still carries the pre-migration materialized true (no
+ * autoCloseOnExitDefaultMigrated flag) is rewritten to false so sync cannot
+ * resurrect auto-close. The cost: a user who deliberately enabled auto-close
+ * before this release must re-enable it once.
+ */
+export function migrateMaterializedAutoCloseOnExitDefault(): void {
+  if (localStorageAdapter.readBoolean(STORAGE_KEY_TERM_AUTO_CLOSE_EXIT_MIGRATED)) return;
+  const stored = localStorageAdapter.read<Partial<TerminalSettings>>(STORAGE_KEY_TERM_SETTINGS);
+  if (stored?.autoCloseOnExit === true) {
+    localStorageAdapter.write(STORAGE_KEY_TERM_SETTINGS, { ...stored, autoCloseOnExit: false });
+  }
+  localStorageAdapter.writeBoolean(STORAGE_KEY_TERM_AUTO_CLOSE_EXIT_MIGRATED, true);
+}
+
 // Auto-detect default hotkey scheme based on platform
 export const DEFAULT_HOTKEY_SCHEME: HotkeyScheme =
   typeof navigator !== 'undefined' && /Mac|iPhone|iPad|iPod/i.test(navigator.platform)

application/state/sftp/externalUploadRuntime.test.ts

@@ -1,7 +1,7 @@
 import test from "node:test";
 import assert from "node:assert/strict";
 
-import { UploadController } from "../../../lib/uploadService";
+import { UploadController, uploadEntriesDirect } from "../../../lib/uploadService";
 import {
   cancelExternalUploadRuntime,
   getExternalUploadController,
@@ -37,3 +37,64 @@ test("external upload controls survive their originating panel unmount", async (
   assert.equal(getExternalUploadController("folder-1"), undefined);
   assert.equal(getExternalUploadController("child-1"), undefined);
 });
+
+for (const selectedFile of ["a.bin", "c.bin"]) {
+  test(`cancelling independent ${selectedFile} preserves its active and queued upload siblings`, async (t) => {
+    resetExternalUploadRuntimeForTests();
+    t.after(resetExternalUploadRuntimeForTests);
+    const controller = new UploadController();
+    const cancelled: string[] = [];
+    const stagedCancelled: string[] = [];
+    const ids = new Map<string, string>();
+    const pending = new Map<string, (cancelled?: boolean) => void>();
+    const started: string[] = [];
+    const upload = uploadEntriesDirect(
+      ["a.bin", "b.bin", "c.bin"].map((name) => ({
+        file: null, relativePath: name, isDirectory: false, localPath: `/local/${name}`, size: 8,
+      })),
+      {
+        targetPath: "/remote", sftpId: "fixture", isLocal: false,
+        fileTransferConcurrency: 2, joinPath: (base, name) => `${base}/${name}`,
+        callbacks: {
+          onTaskCreated: (task) => {
+            ids.set(task.fileName, task.id);
+            registerExternalUploadController(task.id, controller, "file");
+          },
+        },
+        bridge: {
+          mkdirSftp: async () => {},
+          cancelStagedUploadFile: async (id) => { stagedCancelled.push(id); },
+          cancelTransfer: async (id) => { cancelled.push(id); pending.get(id)?.(true); },
+          startStreamTransfer: ({ transferId, sourcePath }) => new Promise((resolve) => {
+            started.push(sourcePath);
+            pending.set(transferId, (cancelled = false) => resolve({ transferId, cancelled }));
+          }),
+        },
+      },
+      controller,
+    );
+    t.after(async () => {
+      await controller.cancel();
+      for (const finish of pending.values()) finish(true);
+      await upload;
+    });
+    await new Promise(setImmediate);
+    assert.deepEqual(started, ["/local/a.bin", "/local/b.bin"]);
+    const selectedId = ids.get(selectedFile)!;
+    await cancelExternalUploadRuntime(selectedId);
+    assert.deepEqual(cancelled, [selectedId]);
+    assert.deepEqual(stagedCancelled, [selectedId]);
+    assert.equal(controller.isCancelled(), false);
+    await new Promise(setImmediate);
+    assert.deepEqual(started, selectedFile === "a.bin"
+      ? ["/local/a.bin", "/local/b.bin", "/local/c.bin"]
+      : ["/local/a.bin", "/local/b.bin"]);
+    for (const [id, finish] of pending) if (id !== selectedId) finish();
+    const results = (await upload).sort((a, b) => a.fileName.localeCompare(b.fileName));
+    assert.deepEqual(results, ["a.bin", "b.bin", "c.bin"].map((fileName) => (
+      fileName === selectedFile
+        ? { fileName, success: false, cancelled: true }
+        : { fileName, success: true }
+    )));
+  });
+}

application/state/sftp/externalUploadRuntime.ts

@@ -5,11 +5,13 @@ import type { UploadController } from "../../../lib/uploadService";
 // terminal only removes the view; the global transfer runtime can still cancel
 // the upload, and the upload's own finally block releases these entries.
 const controllersByTaskId = new Map<string, UploadController>();
+const scopesByTaskId = new Map<string, "file" | "batch">();
 const taskIdsByController = new Map<UploadController, Set<string>>();
 
 export function registerExternalUploadController(
   taskId: string,
   controller: UploadController,
+  scope: "file" | "batch" = "batch",
 ): void {
   if (!taskId) return;
   const previous = controllersByTaskId.get(taskId);
@@ -19,6 +21,7 @@ export function registerExternalUploadController(
     if (previousIds?.size === 0) taskIdsByController.delete(previous);
   }
   controllersByTaskId.set(taskId, controller);
+  scopesByTaskId.set(taskId, scope);
   const taskIds = taskIdsByController.get(controller) ?? new Set<string>();
   taskIds.add(taskId);
   taskIdsByController.set(controller, taskIds);
@@ -30,6 +33,7 @@ export function unregisterExternalUploadController(controller: UploadController)
   for (const taskId of taskIds) {
     if (controllersByTaskId.get(taskId) === controller) {
       controllersByTaskId.delete(taskId);
+      scopesByTaskId.delete(taskId);
     }
   }
   taskIdsByController.delete(controller);
@@ -40,6 +44,10 @@ export function getExternalUploadController(taskId: string): UploadController |
 }
 
 export async function cancelExternalUploadRuntime(taskId?: string): Promise<boolean> {
+  if (taskId && scopesByTaskId.get(taskId) === "file") {
+    await controllersByTaskId.get(taskId)?.cancelFile(taskId);
+    return true;
+  }
   const controllers = taskId
     ? [controllersByTaskId.get(taskId)].filter((value): value is UploadController => !!value)
     : [...taskIdsByController.keys()];
@@ -50,5 +58,6 @@ export async function cancelExternalUploadRuntime(taskId?: string): Promise<bool
 
 export function resetExternalUploadRuntimeForTests(): void {
   controllersByTaskId.clear();
+  scopesByTaskId.clear();
   taskIdsByController.clear();
 }

application/state/sftp/useSftpExternalOperations.ts

@@ -201,8 +201,8 @@ export const useSftpExternalOperations = (
     return { sftpId, release: () => {} };
   }, [ensureRemoteSftpId, getActivePane, getPaneByConnectionId, getPaneByTabId, getSideByTabId, sftpSessionsRef]);
 
-  const registerUploadController = useCallback((taskId: string, controller: UploadController) => {
-    registerExternalUploadController(taskId, controller);
+  const registerUploadController = useCallback((taskId: string, controller: UploadController, scope: "file" | "batch" = "batch") => {
+    registerExternalUploadController(taskId, controller, scope);
   }, []);
 
   const unregisterUploadController = useCallback((controller: UploadController) => {
@@ -222,7 +222,7 @@ export const useSftpExternalOperations = (
       callbacks.onScanningProgress?.(taskId, progress);
     },
     onTaskCreated: (task) => {
-      registerUploadController(task.id, controller);
+      registerUploadController(task.id, controller, !task.isDirectory && !task.parentTaskId ? "file" : "batch");
       if (task.parentTaskId) {
         registerUploadController(task.parentTaskId, controller);
       }

application/state/terminalAutoReconnect.test.ts

@@ -58,6 +58,52 @@ test("normal shell exits do not auto reconnect", () => {
   );
 });
 
+test("administrative idle, timeout, and exit-signal disconnects do not auto reconnect", () => {
+  for (const evt of [
+    { reason: "timeout" as const },
+    { reason: "timeout" as const, exitCode: 0 },
+    { reason: "timeout" as const, error: "Connection timeout to example.com" },
+    { reason: "signaled" as const, exitSignal: "SIGHUP" },
+    { reason: "signaled" as const, exitSignal: "SIGTERM" },
+    { reason: "signaled" as const },
+    // A path that still says "closed" but plumbed the exit-signal is the same kick.
+    { reason: "closed" as const, exitSignal: "SIGUSR2" },
+    { reason: "closed" as const, exitSignal: "  SIGHUP  " },
+  ]) {
+    assert.equal(
+      shouldAutoReconnectAfterExit({
+        evt,
+        host: sshHost,
+        terminalSettings: { sshAutoReconnectEnabled: true },
+        hasEverConnected: true,
+      }),
+      false,
+    );
+  }
+});
+
+test("transport drops still auto reconnect", () => {
+  for (const evt of [
+    { reason: "closed" as const },
+    { reason: "error" as const, error: "connection reset" },
+    { reason: "closed" as const, remoteClosedWithoutExitStatus: true },
+    { reason: "closed" as const, exitSignal: "" },
+    { reason: "closed" as const, exitSignal: "   " },
+    { reason: "error" as const, error: "read ECONNRESET", exitSignal: "" },
+    { reason: "error" as const, error: "read ECONNRESET", exitSignal: "SIGHUP" },
+  ]) {
+    assert.equal(
+      shouldAutoReconnectAfterExit({
+        evt,
+        host: sshHost,
+        terminalSettings: { sshAutoReconnectEnabled: true },
+        hasEverConnected: true,
+      }),
+      true,
+    );
+  }
+});
+
 test("auto reconnect ignores protocols that already have different lifecycle semantics", () => {
   const variants = [
     { protocol: "local" as const, hostname: "localhost" },

application/state/terminalAutoReconnect.ts

@@ -40,7 +40,16 @@ export function shouldAutoReconnectAfterExit({
   if (!hasEverConnected) return false;
   if (!isTerminalAutoReconnectEnabled(terminalSettings)) return false;
   if (!isAutoReconnectableSshHost(host)) return false;
-  return evt.reason !== "exited";
+  // "exited" is a shell exit. "timeout" is an administrative idle/TMOUT logout
+  // (or a connect timeout). "signaled" — or a plumbed exit-signal on an
+  // otherwise "closed" end — is a server kick (idle policy, SIGHUP, SIGTERM).
+  // Reconnecting would fight that policy. Transport "error" and bare "closed"
+  // still retry.
+  if (evt.reason === "error") return true;
+  if (evt.reason === "exited" || evt.reason === "timeout" || evt.reason === "signaled") {
+    return false;
+  }
+  return typeof evt.exitSignal !== "string" || evt.exitSignal.trim().length === 0;
 }
 
 export function shouldContinueAutoReconnectAfterFailure({

application/state/terminalConnectionReuse.test.ts

@@ -224,3 +224,31 @@ test("split and copy session clones preserve isolated plugin connection snapshot
   assert.equal(split.reuseConnectionFromSessionId, undefined);
   assert.equal(copied.reuseConnectionFromSessionId, undefined);
 });
+
+for (const clone of [createSplitTerminalSessionClone, createCopiedTerminalSessionClone]) {
+  test(`${clone.name} keeps the type of an explicit local shell despite global settings`, () => {
+    for (const [localShell, shellType] of [["cmd.exe", "cmd"], ["pwsh.exe", "powershell"]] as const) {
+      const source = session({ protocol: "local", localShell, shellType });
+      const copied = clone(source, { id: "clone", localShellType: "posix" });
+      assert.equal(copied.localShell, localShell);
+      assert.equal(copied.shellType, shellType);
+      assert.equal(clone({ ...source, shellType: undefined },
+        { id: "legacy", localShellType: "posix" }).shellType, shellType);
+    }
+    const implicit = clone(session({ protocol: "local", shellType: "cmd" }),
+      { id: "clone-default", localShellType: "posix" });
+    assert.equal(implicit.shellType, "posix", "implicit shells still follow global settings");
+  });
+}
+
+test("copied backend-default local snapshot retains its shell semantics after global settings change", () => {
+  const source = session({ protocol: "local", localShell: "", localShellArgs: [], shellType: "powershell", localStartDir: "~" });
+  for (const clone of [
+    createCopiedTerminalSessionClone(source, { id: "copy-default-snapshot", localShellType: "posix" }),
+    createSplitTerminalSessionClone(source, { id: "split-default-snapshot", localShellType: "posix" }),
+  ]) {
+    assert.equal(clone.localShell, "");
+    assert.equal(clone.shellType, "powershell");
+    assert.equal(clone.localStartDir, "~");
+  }
+});

application/state/terminalConnectionReuse.ts

@@ -1,4 +1,5 @@
 import type { TerminalSession } from "../../domain/models";
+import { classifyLocalShellType } from "../../lib/localShell";
 
 type SftpReuseCandidate = Pick<
   TerminalSession,
@@ -44,7 +45,12 @@ function getClonedShellType(
   session: TerminalSession,
   localShellType?: TerminalSession["shellType"],
 ): TerminalSession["shellType"] {
-  return session.protocol === "local" ? localShellType : session.shellType;
+  if (session.protocol !== "local") return session.shellType;
+  // Clones retain an explicit per-session executable, so its shell type must
+  // survive a different global default (e.g. saved CMD with WSL in Settings).
+  return session.localShell !== undefined
+    ? (session.shellType ?? classifyLocalShellType(session.localShell))
+    : localShellType;
 }
 
 function createTerminalSessionClone(

application/state/useAIState.fork.test.ts

@@ -0,0 +1,134 @@
+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.ts';
+import { getAgentRuntime } from '../../infrastructure/ai/harness/globalAgentRuntime.ts';
+import { useAIState } from './useAIState.ts';
+import { useAISessionsStore } from './aiSessionsStore.ts';
+import { setLatestAISessionsSnapshot } from './aiStateSnapshots.ts';
+
+const SOURCE_SESSION: AISession = {
+  id: 'chat-source',
+  title: 'Fork source',
+  agentId: 'catty',
+  scope: { type: 'terminal', targetId: 'terminal-a' },
+  messages: [
+    { id: 'user-1', role: 'user', content: 'first prompt', timestamp: 1 },
+    { id: 'assistant-1', role: 'assistant', content: 'first answer', timestamp: 2 },
+    {
+      id: 'user-2',
+      role: 'user',
+      content: 'bad last prompt',
+      timestamp: 3,
+      attachments: [
+        { base64Data: 'QUJD', mediaType: 'text/plain', filename: 'note.txt', lineCount: 2 },
+      ],
+    },
+    { id: 'assistant-2', role: 'assistant', content: 'bad answer', timestamp: 4 },
+  ],
+  createdAt: 1,
+  updatedAt: 4,
+};
+
+type HookCapture = {
+  ai: ReturnType<typeof useAIState> | null;
+  sessions: AISession[];
+  activeSessionIdMap: Record<string, string | null>;
+};
+
+function ForkHarness({ capture }: { capture: HookCapture }) {
+  capture.ai = useAIState();
+  const store = useAISessionsStore();
+  capture.sessions = store.sessions as AISession[];
+  capture.activeSessionIdMap = store.activeSessionIdMap as Record<string, string | null>;
+  return null;
+}
+
+async function setupAiState(sessions: AISession[]) {
+  const dom = new JSDOM('<!doctype html><html><body></body></html>', {
+    url: 'http://localhost',
+  });
+  Object.defineProperty(globalThis, 'window', { configurable: true, value: dom.window });
+  Object.defineProperty(globalThis, 'document', { configurable: true, value: dom.window.document });
+  Object.defineProperty(globalThis, 'localStorage', { configurable: true, value: dom.window.localStorage });
+  Object.defineProperty(globalThis, 'CustomEvent', { configurable: true, value: dom.window.CustomEvent });
+  Object.defineProperty(globalThis, 'Event', { configurable: true, value: dom.window.Event });
+  Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', { configurable: true, value: true });
+
+  setLatestAISessionsSnapshot(sessions);
+  dom.window.localStorage.setItem('netcatty_ai_sessions_v1', JSON.stringify(sessions));
+
+  const container = document.createElement('div');
+  document.body.appendChild(container);
+  const root = createRoot(container);
+  const capture: HookCapture = { ai: null, sessions: [], activeSessionIdMap: {} };
+  await act(async () => {
+    root.render(React.createElement(ForkHarness, { capture }));
+  });
+  return { dom, container, root, capture };
+}
+
+test('fork retains the completed prefix, replay metadata, and source-owned outputs', async () => {
+  const runtime = getAgentRuntime();
+  const outputStore = runtime.getToolOutputStore('chat-source');
+  const handle = outputStore.store({ chatSessionId: 'chat-source', capabilityId: 'terminal.exec', content: 'saved output' });
+  runtime.getSessionStateStore().updateFromToolResult('chat-source', 'terminal_start',
+    { sessionId: 'terminal-a', command: 'running-command' },
+    JSON.stringify({ jobId: 'source-job', status: 'running', nextOffset: 7 }), false);
+  const source = structuredClone(SOURCE_SESSION);
+  source.externalSessionId = 'original-provider-thread';
+  source.messages[1].content = `Preview handleId=${handle.id}`;
+  source.messages[1].providerContinuation = { reasoningParts: [{ text: 'checked', providerOptions: { anthropic: { signature: 'signed-thinking' } } }] };
+  const { dom, container, root, capture } = await setupAiState([source]);
+  let branch: AISession | null = null;
+  await act(async () => { branch = await capture.ai!.forkSessionFromMessage(source.id, 'assistant-1', { type: 'terminal', targetId: 'reconnected' }); });
+  assert.ok(branch);
+  assert.notEqual(branch!.id, source.id);
+  assert.equal(branch!.externalSessionId, undefined);
+  assert.deepEqual(branch!.messages[1].providerContinuation, source.messages[1].providerContinuation);
+  assert.match(branch!.messages[1].content, /Preview/);
+  assert.doesNotMatch(branch!.messages[1].content, /handleId=/);
+  assert.deepEqual(branch!.scope, { type: 'terminal', targetId: 'reconnected', hostIds: undefined });
+  assert.equal(capture.activeSessionIdMap['terminal:reconnected'], branch!.id);
+  assert.deepEqual({ ...capture.sessions.find(item => item.id === source.id), updatedAt: source.updatedAt }, source);
+  assert.equal(outputStore.read({ handleId: handle.id }, branch!.id), null);
+  assert.equal(outputStore.read({ handleId: handle.id }, source.id), 'saved output');
+  assert.deepEqual(runtime.getSessionStateStore().get(branch!.id).activeJobs, {});
+  assert.ok(runtime.getSessionStateStore().get(source.id).activeJobs['source-job']);
+  runtime.getSessionStateStore().clear(source.id);
+  outputStore.prune(source.id);
+  await act(async () => root.unmount()); container.remove(); dom.window.close();
+});
+
+test('fork rejects an incomplete boundary without adding a chat', async () => {
+  const source = structuredClone(SOURCE_SESSION);
+  source.messages[1].executionStatus = 'failed';
+  const { dom, container, root, capture } = await setupAiState([source]);
+  let result: unknown;
+  await act(async () => { result = await capture.ai!.forkSessionFromMessage(source.id, 'assistant-1'); });
+  assert.equal(result, null);
+  assert.equal(capture.sessions.length, 1);
+  await act(async () => root.unmount()); container.remove(); dom.window.close();
+});
+
+for (const newerCount of [49, 50]) {
+  test(`fork preserves the original on reload with ${newerCount} newer chats`, async () => {
+    const newer = Array.from({ length: newerCount }, (_, index) => ({ ...structuredClone(SOURCE_SESSION), id: `history-${index}`, updatedAt: 100 + index }));
+    const { dom, container, root, capture } = await setupAiState([...newer, SOURCE_SESSION]);
+    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);
+    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();
+    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);
+    await act(async () => reloaded.root.unmount()); reloaded.container.remove(); reloaded.dom.window.close();
+  });
+}

application/state/useAIState.ts

@@ -55,6 +55,7 @@ import {
 import { convertFilesToUploads } from './useFileUpload';
 import { removeProviderReferences } from './aiProviderCleanup';
 import { publishAISessionsSnapshot } from './aiSessionsStore';
+import { planSessionFork } from '../../domain/aiSessionFork';
 import {
   AI_STATE_CHANGED_DRAFTS_BY_SCOPE,
   AI_STATE_CHANGED_PANEL_VIEW_BY_SCOPE,
@@ -86,6 +87,11 @@ import {
   retargetWorkspaceActiveChatAfterMemberLoss,
   seedWorkspaceAIActiveSessionFromMembers,
 } from '../../domain/workspaceAiScopeHandoff';
+import {
+  buildUndoLastTurnBranch,
+  type UndoLastTurnRestoredDraft,
+} from '../../domain/aiUndoLastTurn';
+
 
 function providerPatchIsNoop(
   current: ProviderConfig,
@@ -675,6 +681,57 @@ export function useAIState() {
     };
   }, [persistSessions]);
 
+  // "Fork from here": copy the conversation up to a completed assistant
+  // response into a new session and make it the scope's active chat. The
+  // original session stays untouched in history. Pure boundary validation and
+  // plan building live in domain/aiSessionFork; the fork has no original
+  // external session id or pending-turn state. Per-message replay metadata is
+  // preserved; output handles and running jobs remain owned by the source.
+  // Null is returned when the boundary is not forkable.
+  // `viewingScope` is the panel scope the fork was requested from; the branch
+  // is created there so the fork is active and visible in the very scope that
+  // is viewing it, even when the source session carries a stale scope (e.g. a
+  // terminal chat resumed in a reconnected terminal or a merged workspace).
+  const forkSessionFromMessage = useCallback(async (
+    sessionId: string,
+    messageId: string,
+    viewingScope?: Pick<AISessionScope, 'type' | 'targetId'>,
+  ): Promise<AISession | null> => {
+    const source = sessionsRef.current.find(s => s.id === sessionId);
+    if (!source) return null;
+    const plan = planSessionFork(source, messageId);
+    if (!plan.ok) return null;
+    const now = Date.now();
+    const fork: AISession = {
+      id: `ai_${now}_${Math.random().toString(36).slice(2, 8)}`,
+      title: plan.title,
+      agentId: source.agentId,
+      scope: {
+        ...source.scope,
+        // Host membership stays with the source (the messages were produced
+        // there); the scope the fork belongs to is the viewing scope.
+        ...(viewingScope ? { type: viewingScope.type, targetId: viewingScope.targetId } : {}),
+        hostIds: source.scope.hostIds ? [...source.scope.hostIds] : undefined,
+      },
+      messages: plan.messages,
+      createdAt: now,
+      updatedAt: now,
+    };
+    if (plan.contextCompaction) {
+      fork.contextCompaction = plan.contextCompaction;
+    }
+    setSessionsRaw(prev => {
+      // Keep the source alongside its branch within the existing history limit.
+      const next = [fork, { ...source, updatedAt: now }, ...prev.filter(session => session.id !== source.id)];
+      setLatestAISessionsSnapshot(next);
+      persistSessions(next);
+      return next;
+    });
+    const scopeKey = `${fork.scope.type}:${fork.scope.targetId ?? ''}`;
+    setActiveSessionId(scopeKey, fork.id);
+    return fork;
+  }, [persistSessions, setActiveSessionId]);
+
   const createSession = useCallback((scope: AISessionScope, agentId?: string): AISession => {
     const now = Date.now();
     const session: AISession = {
@@ -697,6 +754,32 @@ export function useAIState() {
     return session;
   }, [defaultAgentId, persistSessions, setActiveSessionId]);
 
+  // Non-destructive "undo last turn": branch the session at the boundary
+  // before the latest user message and keep the original in history intact.
+  // Returns the new branch id plus the undone user message for the composer.
+  const undoLastTurnInSession = useCallback(async (sessionId: string): Promise<{
+    sessionId: string;
+    restored: UndoLastTurnRestoredDraft;
+  } | null> => {
+    const nextId = `ai_${Date.now()}_${Math.random().toString(36).slice(2, 8)}`;
+    const source = sessionsRef.current.find(s => s.id === sessionId);
+    if (!source) return null;
+    const result = buildUndoLastTurnBranch(source, { newId: nextId, now: Date.now() });
+    if (!result) return null;
+
+    const branched = result.session;
+    setSessionsRaw(prev => {
+      // Keep both recently used chats within the existing history limit.
+      const next = [branched, { ...source, updatedAt: branched.updatedAt }, ...prev.filter(session => session.id !== source.id)];
+      setLatestAISessionsSnapshot(next);
+      persistSessions(next);
+      return next;
+    });
+    const scopeKey = `${branched.scope.type}:${branched.scope.targetId ?? ''}`;
+    setActiveSessionId(scopeKey, branched.id);
+    return { sessionId: branched.id, restored: result.restored };
+  }, [persistSessions, setActiveSessionId]);
+
   const deleteSession = useCallback((sessionId: string, scopeKey?: string) => {
     cleanupDeletedAIChatSessions([sessionId]);
     if (persistTimerRef.current) {
@@ -1275,6 +1358,7 @@ export function useAIState() {
     addDraftFiles,
     removeDraftFile,
     createSession,
+    undoLastTurnInSession,
     deleteSession,
     deleteSessionsByTarget,
     updateSessionTitle,
@@ -1287,6 +1371,7 @@ export function useAIState() {
     seedWorkspaceActiveSessionFromMembers,
     handoffDissolvedWorkspaceScope,
     retargetWorkspaceActiveChatForMemberLoss,
+    forkSessionFromMessage,
   }), [
     providers,
     setProviders,
@@ -1335,6 +1420,7 @@ export function useAIState() {
     addDraftFiles,
     removeDraftFile,
     createSession,
+    undoLastTurnInSession,
     deleteSession,
     deleteSessionsByTarget,
     updateSessionTitle,
@@ -1347,5 +1433,6 @@ export function useAIState() {
     seedWorkspaceActiveSessionFromMembers,
     handoffDissolvedWorkspaceScope,
     retargetWorkspaceActiveChatForMemberLoss,
+    forkSessionFromMessage,
   ]);
 }

application/state/useAIState.undoLastTurn.test.ts

@@ -0,0 +1,194 @@
+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, UploadedFile } 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';
+
+const SCOPE_KEY = 'terminal:terminal-a';
+
+const SOURCE_SESSION: AISession = {
+  id: 'chat-source',
+  title: 'Undo source',
+  agentId: 'catty',
+  scope: { type: 'terminal', targetId: 'terminal-a' },
+  messages: [
+    { id: 'user-1', role: 'user', content: 'first prompt', timestamp: 1 },
+    { id: 'assistant-1', role: 'assistant', content: 'first answer', timestamp: 2 },
+    {
+      id: 'user-2',
+      role: 'user',
+      content: 'bad last prompt',
+      timestamp: 3,
+      attachments: [
+        { base64Data: 'QUJD', mediaType: 'text/plain', filename: 'note.txt', lineCount: 2 },
+      ],
+    },
+    { id: 'assistant-2', role: 'assistant', content: 'bad answer', timestamp: 4 },
+  ],
+  createdAt: 1,
+  updatedAt: 4,
+};
+
+type HookCapture = {
+  ai: ReturnType<typeof useAIState> | null;
+  sessions: AISession[];
+  activeSessionIdMap: Record<string, string | null>;
+};
+
+function UndoHarness({ capture }: { capture: HookCapture }) {
+  capture.ai = useAIState();
+  const store = useAISessionsStore();
+  capture.sessions = store.sessions as AISession[];
+  capture.activeSessionIdMap = store.activeSessionIdMap as Record<string, string | null>;
+  return null;
+}
+
+async function setupAiState(sessions: AISession[]) {
+  const dom = new JSDOM('<!doctype html><html><body></body></html>', {
+    url: 'http://localhost',
+  });
+  Object.defineProperty(globalThis, 'window', { configurable: true, value: dom.window });
+  Object.defineProperty(globalThis, 'document', { configurable: true, value: dom.window.document });
+  Object.defineProperty(globalThis, 'localStorage', { configurable: true, value: dom.window.localStorage });
+  Object.defineProperty(globalThis, 'CustomEvent', { configurable: true, value: dom.window.CustomEvent });
+  Object.defineProperty(globalThis, 'Event', { configurable: true, value: dom.window.Event });
+  Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', { configurable: true, value: true });
+
+  setLatestAISessionsSnapshot(sessions);
+  dom.window.localStorage.setItem('netcatty_ai_sessions_v1', JSON.stringify(sessions));
+
+  const container = document.createElement('div');
+  document.body.appendChild(container);
+  const root = createRoot(container);
+  const capture: HookCapture = { ai: null, sessions: [], activeSessionIdMap: {} };
+  await act(async () => {
+    root.render(React.createElement(UndoHarness, { capture }));
+  });
+  return { dom, container, root, capture };
+}
+
+test('undoLastTurnInSession branches and restores the last user turn', async () => {
+  const { dom, container, root, capture } = await setupAiState([SOURCE_SESSION]);
+  assert.ok(capture.ai);
+
+  let result: Awaited<ReturnType<typeof runUndo>> | null = null;
+  async function runUndo() {
+    return capture.ai!.undoLastTurnInSession('chat-source');
+  }
+
+  await act(async () => {
+    result = await runUndo();
+  });
+
+  assert.ok(result);
+  assert.notEqual(result!.sessionId, 'chat-source');
+
+  const sessions = capture.sessions;
+  const branch = sessions.find((session) => session.id === result!.sessionId);
+  assert.ok(branch);
+  // Branch keeps the conversation up to the boundary before the last turn.
+  assert.deepEqual(
+    branch!.messages.map((message) => message.content),
+    ['first prompt', 'first answer'],
+  );
+  // Original session stays intact (non-destructive).
+  const original = sessions.find((session) => session.id === 'chat-source');
+  assert.equal(original?.messages.length, 4);
+  // Branch becomes the active session for the scope.
+  assert.equal(capture.activeSessionIdMap[SCOPE_KEY], result!.sessionId);
+
+  const attachments = result!.restored.attachments as UploadedFile[];
+  assert.equal(result!.restored.text, 'bad last prompt');
+  assert.equal(attachments.length, 1);
+  assert.equal(attachments[0].filename, 'note.txt');
+  assert.equal(attachments[0].dataUrl, 'data:text/plain;base64,QUJD');
+
+  await act(async () => root.unmount());
+  container.remove();
+  dom.window.close();
+});
+
+test('undoLastTurnInSession returns null when there is nothing to undo', async () => {
+  const emptySession: AISession = {
+    ...SOURCE_SESSION,
+    id: 'chat-empty',
+    messages: [],
+  };
+  const { dom, container, root, capture } = await setupAiState([emptySession]);
+  assert.ok(capture.ai);
+
+  let result: unknown;
+  await act(async () => {
+    result = await capture.ai!.undoLastTurnInSession('chat-empty');
+  });
+  assert.equal(result, null);
+
+  await act(async () => root.unmount());
+  container.remove();
+  dom.window.close();
+});
+
+test('undo copies chat only, preserving original outputs and job ownership', async () => {
+  const runtime = getAgentRuntime();
+  const outputStore = runtime.getToolOutputStore('chat-source');
+  const handle = outputStore.store({
+    chatSessionId: 'chat-source', capabilityId: 'terminal.exec', content: 'original saved output',
+  });
+  const stateStore = runtime.getSessionStateStore();
+  stateStore.updateFromToolResult('chat-source', 'terminal_start',
+    { sessionId: 'terminal-a', command: 'long-running-command' },
+    JSON.stringify({ jobId: 'original-job', status: 'running', nextOffset: 7 }), false);
+  const source = structuredClone(SOURCE_SESSION);
+  source.messages[1].content = `Preview with handleId=${handle.id}`;
+  const { dom, container, root, capture } = await setupAiState([source]);
+  const original = JSON.stringify(source);
+  let result: { sessionId: string } | null = null;
+  await act(async () => { result = await capture.ai!.undoLastTurnInSession(source.id); });
+  assert.ok(result);
+  assert.equal(outputStore.read({ handleId: handle.id }, result!.sessionId), null);
+  assert.equal(outputStore.read({ handleId: handle.id }, source.id), 'original saved output');
+  assert.deepEqual(stateStore.get(result!.sessionId).activeJobs, {});
+  assert.ok(stateStore.get(source.id).activeJobs['original-job']);
+  assert.equal(JSON.stringify({ ...capture.sessions.find(item => item.id === source.id), updatedAt: source.updatedAt }), original);
+  assert.ok(capture.sessions.find(item => item.id === result!.sessionId)!.messages[1].content.includes('Preview'));
+  stateStore.clear(source.id);
+  outputStore.prune(source.id);
+  await act(async () => root.unmount());
+  container.remove(); dom.window.close();
+});
+
+for (const newerCount of [49, 50]) {
+  test(`undo retains an old source and its branch after reload with ${newerCount} newer chats`, async () => {
+    const newer = Array.from({ length: newerCount }, (_, index) => ({
+      ...structuredClone(SOURCE_SESSION), id: `history-${index}`, updatedAt: 100 + index,
+    }));
+    const { dom, container, root, capture } = await setupAiState([...newer, SOURCE_SESSION]);
+    let branchId: string | undefined;
+    await act(async () => {
+      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);
+    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.
+    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));
+    await act(async () => reloaded.root.unmount());
+    reloaded.container.remove(); reloaded.dom.window.close();
+  });
+}

application/state/useExternalMcpToggleState.test.ts

@@ -1,5 +1,8 @@
 import assert from 'node:assert/strict';
 import { describe, it } from 'node:test';
+import { createSessionIdleManager } from '../../electron/bridges/mcpServerBridge/sessionIdleManager.cjs';
+import { STORAGE_KEY_AI_SESSION_IDLE_TIMEOUT_MINUTES } from '../../infrastructure/config/storageKeys';
+import { localStorageAdapter } from '../../infrastructure/persistence/localStorageAdapter';
 import {
   EXTERNAL_MCP_RUNTIME_STATUS_POLL_MS,
   bumpExternalMcpEnableGenerationForTests,
@@ -18,6 +21,7 @@ import {
   resetExternalMcpStartupSyncOnceForTests,
   shouldStartExternalMcpOnStartup,
   shouldWaitForExternalMcpStartupReady,
+  syncExternalMcpConfig,
   syncExternalMcpStartupState,
   syncExternalMcpStartupStateOnce,
   waitForExternalMcpStartupReady,
@@ -63,10 +67,44 @@ describe('useExternalMcpToggleState helpers', () => {
     assert.equal(normalizeExternalMcpIdleTimeoutMinutes(null), 10);
     assert.equal(normalizeExternalMcpIdleTimeoutMinutes(0), 1);
     assert.equal(normalizeExternalMcpIdleTimeoutMinutes(99999), 24 * 60);
-    assert.equal(normalizeSessionIdleTimeoutMinutes(null), 30);
+    assert.equal(normalizeSessionIdleTimeoutMinutes(null), 8 * 60);
     assert.equal(normalizeSessionIdleTimeoutMinutes(0), 1);
   });
 
+  for (const savedMinutes of [null, 30]) {
+    it(`syncs the session idle timeout without replacing saved value ${savedMinutes}`, async () => {
+      const restore = installMemoryLocalStorage();
+      const manager = createSessionIdleManager();
+      try {
+        assert.equal(manager.getTimeoutMinutes(), 8 * 60, 'main-process default');
+        if (savedMinutes !== null) {
+          localStorageAdapter.writeNumber(STORAGE_KEY_AI_SESSION_IDLE_TIMEOUT_MINUTES, savedMinutes);
+        }
+        const expected = savedMinutes ?? manager.getTimeoutMinutes();
+        const received: number[] = [];
+        const bridge = {
+          externalMcpSetConfig: (config: { sessionIdleTimeoutMinutes: number }) => {
+            received.push(config.sessionIdleTimeoutMinutes);
+            manager.setTimeoutMinutes(config.sessionIdleTimeoutMinutes);
+          },
+        };
+        await syncExternalMcpStartupState(bridge);
+        assert.equal(manager.getTimeoutMinutes(), expected, 'startup keeps the intended timeout');
+        syncExternalMcpConfig(bridge);
+        assert.deepEqual(received, [expected, expected]);
+        assert.equal(manager.getTimeoutMinutes(), expected, 'config sync keeps the intended timeout');
+        assert.equal(
+          localStorageAdapter.readNumber(STORAGE_KEY_AI_SESSION_IDLE_TIMEOUT_MINUTES),
+          savedMinutes,
+          'sync does not migrate or overwrite the stored preference',
+        );
+      } finally {
+        manager.clearAll();
+        restore();
+      }
+    });
+  }
+
   it('only starts on launch for persistent+enabled', () => {
     assert.equal(shouldStartExternalMcpOnStartup({ enabled: true, mode: 'persistent' }), true);
     assert.equal(shouldStartExternalMcpOnStartup({ enabled: true, mode: 'temporary' }), false);

application/state/useExternalMcpToggleState.ts

@@ -18,7 +18,7 @@ export type ExternalMcpMode = 'temporary' | 'persistent';
 const DEFAULT_EXTERNAL_MCP_IDLE_TIMEOUT_MINUTES = 10;
 const MIN_EXTERNAL_MCP_IDLE_TIMEOUT_MINUTES = 1;
 const MAX_EXTERNAL_MCP_IDLE_TIMEOUT_MINUTES = 24 * 60;
-const DEFAULT_SESSION_IDLE_TIMEOUT_MINUTES = 30;
+const DEFAULT_SESSION_IDLE_TIMEOUT_MINUTES = 480;
 /** Keep top-bar / settings switch state aligned with runtime auto-disable. */
 export const EXTERNAL_MCP_RUNTIME_STATUS_POLL_MS = 3000;
 

application/state/useHostOpenSessionReuse.test.ts

@@ -0,0 +1,383 @@
+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 type { GroupConfig, Host, Identity, SSHKey, TerminalSession } from '../../domain/models';
+import { updateRestoredSessionStatusState } from './sessionRestoreState';
+import { resolveEffectiveTerminalHost, resolveTerminalSessionHost } from '../../domain/terminalHostResolution';
+import { createHostTerminalSession } from './sessionFactories';
+import { resolveHostDefaultLocalShell } from '../../domain/localShellHost';
+import { useHostOpenSessionReuse } from './useHostOpenSessionReuse';
+import { resolveShellSetting } from '../../lib/useDiscoveredShells';
+
+(globalThis as { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+const effective = (host: Host) => host;
+const host = (extra: Partial<Host> = {}): Host => ({
+  id: 'host', hostname: 'original.invalid', username: 'user', label: 'Original', os: 'linux', tags: [], protocol: 'ssh', ...extra,
+});
+
+async function harness(initial: Host, extra: { hosts?: Host[]; keys?: SSHKey[]; identities?: Identity[]; sessions?: TerminalSession[]; resolveEffectiveHost?: (host: Host) => Host } = {}) {
+  let hosts = [initial, ...(extra.hosts ?? [])];
+  let keys = extra.keys ?? [];
+  let identities = extra.identities ?? [];
+  let sessions: TerminalSession[] = extra.sessions ?? [{ ...createHostTerminalSession('tab', initial), status: 'connected' }];
+  let find: ReturnType<typeof useHostOpenSessionReuse>;
+  function Harness() {
+    find = useHostOpenSessionReuse({ sessions, hosts, keys, identities, resolveEffectiveHost: extra.resolveEffectiveHost ?? effective });
+    return null;
+  }
+  let renderer: ReactTestRenderer;
+  await act(async () => { renderer = create(React.createElement(Harness)); });
+  return {
+    find: () => find(initial.id),
+    async update(input: { host?: Host; hosts?: Host[]; keys?: SSHKey[]; identities?: Identity[]; sessions?: TerminalSession[] }) {
+      hosts = input.hosts ?? (input.host ? [input.host, ...hosts.slice(1)] : hosts);
+      keys = input.keys ?? keys;
+      identities = input.identities ?? identities;
+      sessions = input.sessions ?? sessions;
+      await act(async () => renderer.update(React.createElement(Harness)));
+    },
+    close: () => act(async () => renderer.unmount()),
+  };
+}
+
+for (const [field, value] of [
+  ['hostname', 'replacement.invalid'], ['username', 'other-user'], ['port', 2222],
+  ['protocol', 'telnet'], ['password', 'new-password'], ['authMethod', 'key'],
+  ['hostChain', { hostIds: ['jump'] }],
+  ['proxyConfig', { type: 'socks5', host: 'proxy.invalid', port: 1080 }],
+] as const) {
+  test(`a saved ${field} edit cannot reuse the old tab`, async (t) => {
+    const original = host({ password: 'old-password', authMethod: 'password' });
+    const api = await harness(original, { hosts: [host({ id: 'jump', hostname: 'jump.invalid' })] });
+    t.after(api.close);
+    assert.equal((await api.find())?.sessionId, 'tab');
+    await api.update({ host: { ...original, [field]: value } });
+    assert.equal(await api.find(), undefined);
+  });
+}
+
+test('renaming the target and jump host keeps the same tab eligible', async (t) => {
+  const original = host({ hostChain: { hostIds: ['jump'] } });
+  const jump = host({ id: 'jump', hostname: 'jump.invalid' });
+  const api = await harness(original, { hosts: [jump] });
+  t.after(api.close);
+  await api.update({ hosts: [{ ...original, label: 'Renamed', fontSize: 16, notes: 'Updated note' }, { ...jump, label: 'Renamed jump' }] });
+  assert.equal((await api.find())?.sessionId, 'tab');
+});
+
+test('changing a jump endpoint or its password rejects the original connection', async (t) => {
+  const original = host({ hostChain: { hostIds: ['jump'] } });
+  const jump = host({ id: 'jump', hostname: 'jump.invalid', password: 'old' });
+  const api = await harness(original, { hosts: [jump] });
+  t.after(api.close);
+  for (const changed of [{ ...jump, hostname: 'new-jump.invalid' }, { ...jump, password: 'new' }]) {
+    await api.update({ hosts: [original, changed] });
+    assert.equal(await api.find(), undefined);
+  }
+});
+
+test('rotating a referenced identity or key keeps stable IDs from masking auth changes', async (t) => {
+  const identity: Identity = { id: 'identity', label: 'Login', username: 'user', password: 'old', authMethod: 'password', created: 0 };
+  const original = host({ identityId: identity.id });
+  const api = await harness(original, { identities: [identity] });
+  t.after(api.close);
+  assert.equal((await api.find())?.sessionId, 'tab');
+  await api.update({ identities: [{ ...identity, password: 'rotated' }] });
+  assert.equal(await api.find(), undefined);
+  const key: SSHKey = { id: 'key', label: 'Key', type: 'ED25519', privateKey: 'old-key', source: 'generated', category: 'key', created: 0 };
+  const keyHost = host({ identityFileId: key.id, authMethod: 'key' });
+  const keyApi = await harness(keyHost, { keys: [key] });
+  t.after(keyApi.close);
+  assert.equal((await keyApi.find())?.sessionId, 'tab');
+  await keyApi.update({ keys: [{ ...key, privateKey: 'rotated-key' }] });
+  assert.equal(await keyApi.find(), undefined);
+});
+
+for (const [field, value] of [
+  ['baudRate', 19200], ['dataBits', 7], ['stopBits', 2], ['parity', 'even'], ['flowControl', 'rts/cts'],
+] as const) {
+  test(`a serial ${field} edit must not reuse the opening parameters`, async (t) => {
+    const original = host({ protocol: 'serial', hostname: '/dev/tty.test', username: '', serialConfig: { path: '/dev/tty.test', baudRate: 9600, dataBits: 8, stopBits: 1, parity: 'none', flowControl: 'none' } });
+    const api = await harness(original);
+    t.after(api.close);
+    assert.equal((await api.find())?.sessionId, 'tab');
+    await api.update({ host: { ...original, serialConfig: { ...original.serialConfig!, [field]: value } } });
+    assert.equal(await api.find(), undefined);
+  });
+}
+
+test('unchanged legacy serial defaults still match their opening snapshot', async (t) => {
+  const original = host({ protocol: 'serial', hostname: '/dev/tty.test', username: '', port: 9600 });
+  const api = await harness(original);
+  t.after(api.close);
+  assert.equal((await api.find())?.sessionId, 'tab');
+});
+
+test('the captured serial settings come from the opening session even if the vault was already edited', async (t) => {
+  const original = host({ protocol: 'serial', hostname: '/dev/tty.test', username: '', serialConfig: { path: '/dev/tty.test', baudRate: 9600 } });
+  const session: TerminalSession = { ...createHostTerminalSession('tab', original), status: 'connected' };
+  const api = await harness({ ...original, serialConfig: { ...original.serialConfig!, baudRate: 19200 } }, { sessions: [session] });
+  t.after(api.close);
+  assert.equal(await api.find(), undefined);
+});
+
+for (const changedField of ['configuration', 'credentialId'] as const) {
+  test(`a restored plugin tab keeps its opening ${changedField} after manual reconnect`, async (t) => {
+    const providerId = 'com.example.transport.connection';
+    const original = host({ protocol: `plugin:${providerId}`, pluginConnection: { providerId, configuration: { endpoint: 'original.invalid' }, credentialId: 'original-credential-reference' } });
+    const edited = { ...original, pluginConnection: { ...original.pluginConnection!, [changedField]: changedField === 'configuration' ? { endpoint: 'replacement.invalid' } : 'replacement-credential-reference' } };
+    const restored: TerminalSession = { ...createHostTerminalSession('tab', original), status: 'disconnected', restoreState: 'restored-disconnected' };
+    const api = await harness(edited, { sessions: [restored] });
+    t.after(api.close);
+    assert.equal(await api.find(), undefined);
+    const reconnecting = updateRestoredSessionStatusState([restored], restored.id, 'connecting');
+    const actual = resolveTerminalSessionHost({ session: reconnecting[0], hosts: [edited], groupConfigs: [], proxyProfiles: [], localOs: 'linux' });
+    assert.deepEqual(actual.pluginConnection, original.pluginConnection, 'the real terminal resolver uses the restored opening configuration');
+    await api.update({ sessions: reconnecting });
+    assert.equal(await api.find(), undefined, 'host_open must not call that old transport the edited vault connection');
+  });
+}
+
+test('an unchanged restored plugin configuration can be reused after manual reconnect', async (t) => {
+  const providerId = 'com.example.transport.connection';
+  const original = host({ protocol: `plugin:${providerId}`, pluginConnection: { providerId, configuration: { endpoint: 'original.invalid' } } });
+  const restored: TerminalSession = { ...createHostTerminalSession('tab', original), status: 'disconnected', restoreState: 'restored-disconnected' };
+  const api = await harness({ ...original, label: 'Renamed' }, { sessions: [restored] });
+  t.after(api.close);
+  await api.update({ sessions: updateRestoredSessionStatusState([restored], restored.id, 'connecting') });
+  assert.equal((await api.find())?.sessionId, 'tab');
+});
+
+for (const [field, value] of [
+  ['telnetPort', 2324], ['telnetUsername', 'other-telnet-user'], ['telnetPassword', 'rotated-telnet-password'],
+] as const) {
+  test(`a Telnet ${field} edit cannot reuse the old transport`, async (t) => {
+    const original = host({ protocol: 'telnet', telnetPort: 2323, telnetUsername: 'telnet-user', telnetPassword: 'telnet-password' });
+    const api = await harness(original);
+    t.after(api.close);
+    assert.equal((await api.find())?.sessionId, 'tab');
+    await api.update({ host: { ...original, [field]: value } });
+    assert.equal(await api.find(), undefined);
+  });
+}
+
+test('Telnet identity credential rotation and missing identity reject reuse', async (t) => {
+  const identity: Identity = { id: 'telnet-login', label: 'Telnet login', username: 'telnet-user', password: 'original', authMethod: 'password', created: 0 };
+  const original = host({ protocol: 'telnet', telnetIdentityId: identity.id });
+  const api = await harness(original, { identities: [identity] });
+  t.after(api.close);
+  assert.equal((await api.find())?.sessionId, 'tab');
+  for (const identities of [[{ ...identity, username: 'other-user' }], [{ ...identity, password: 'rotated' }], []]) {
+    await api.update({ identities });
+    assert.equal(await api.find(), undefined);
+  }
+});
+
+test('Telnet explicit empty login does not fall back to SSH login fields', async (t) => {
+  const original = host({ protocol: 'telnet', telnetUsername: '', telnetPassword: '', password: 'ssh-only' });
+  const api = await harness(original);
+  t.after(api.close);
+  assert.equal((await api.find())?.sessionId, 'tab');
+  await api.update({ host: { ...original, label: 'Renamed', username: 'unrelated-ssh-user', password: 'unrelated-ssh-password', identityId: 'missing-ssh-identity', telnetPort: 23 } });
+  assert.equal((await api.find())?.sessionId, 'tab');
+  await api.update({ host: { ...original, telnetUsername: undefined, telnetPassword: undefined } });
+  assert.equal(await api.find(), undefined, 'removing explicit empty overrides enables the actual fallback login');
+});
+
+for (const transport of [{ protocol: 'et' as const }, { protocol: 'ssh' as const, etEnabled: true }]) {
+  test(`changing a jump ET server port rejects the old ${JSON.stringify(transport)} transport`, async (t) => {
+    const original = host({ ...transport, hostChain: { hostIds: ['jump'] } });
+    const jump = host({ id: 'jump', hostname: 'jump.invalid', etPort: 2022 });
+    const api = await harness(original, { hosts: [jump] });
+    t.after(api.close);
+    assert.equal((await api.find())?.sessionId, 'tab');
+    await api.update({ hosts: [original, { ...jump, etPort: 3022 }] });
+    assert.equal(await api.find(), undefined);
+  });
+}
+
+test('serial direct auto-login password is not masked by an unrelated SSH identity', async (t) => {
+  const identity: Identity = { id: 'ssh-login', label: 'SSH login', username: 'ssh-user', password: 'ssh-password', authMethod: 'password', created: 0 };
+  const original = host({ protocol: 'serial', hostname: '/dev/tty.test', username: '', password: 'serial-password', identityId: identity.id });
+  const api = await harness(original, { identities: [identity] });
+  t.after(api.close);
+  assert.equal((await api.find())?.sessionId, 'tab');
+  await api.update({ host: { ...original, password: 'rotated-serial-password' } });
+  assert.equal(await api.find(), undefined);
+});
+
+test('unchanged serial direct username matches the actual auto-login input', async (t) => {
+  const original = host({ protocol: 'serial', hostname: '/dev/tty.test', username: 'serial-user', password: 'serial-password' });
+  const api = await harness(original);
+  t.after(api.close);
+  assert.equal((await api.find())?.sessionId, 'tab');
+  await api.update({ host: { ...original, username: 'other-serial-user' } });
+  assert.equal(await api.find(), undefined);
+});
+
+for (const [field, value] of [
+  ['localShell', '/bin/bash'], ['localShellArgs', ['--norc']], ['localStartDir', '/replacement'],
+] as const) {
+  test(`a saved local ${field} edit cannot reuse the old process`, async (t) => {
+    const original = host({ protocol: 'local', hostname: 'localhost', localShell: '/bin/zsh', localShellArgs: ['-l'], localStartDir: '/original' });
+    const session = { ...createHostTerminalSession('tab', original), status: 'connected', localShell: original.localShell, localShellArgs: original.localShellArgs, localStartDir: original.localStartDir } as TerminalSession;
+    const api = await harness(original, { sessions: [session] });
+    t.after(api.close);
+    assert.equal((await api.find())?.sessionId, 'tab');
+    await api.update({ host: { ...original, [field]: value } });
+    assert.equal(await api.find(), undefined);
+    const alreadyEdited = await harness({ ...original, [field]: value }, { sessions: [session] });
+    t.after(alreadyEdited.close);
+    assert.equal(await alreadyEdited.find(), undefined, 'opening fields come from the actual local session');
+  });
+}
+
+test('local default shell, cwd and empty args match the renderer launch contract', async (t) => {
+  const original = host({ protocol: 'local', hostname: 'localhost' });
+  const api = await harness(original);
+  t.after(api.close);
+  await api.update({ host: { ...original, localShell: '', localStartDir: '', label: 'Renamed' } });
+  assert.equal((await api.find())?.sessionId, 'tab');
+  await api.update({ host: { ...original, localShellArgs: [] } });
+  assert.equal((await api.find())?.sessionId, 'tab', 'the renderer omits empty args so backend login defaults still apply');
+});
+
+for (const [label, proxy] of [
+  ['a missing saved profile', { proxyProfileId: 'missing-profile' }],
+  ['a usable proxy', { proxyConfig: { type: 'socks5', host: 'proxy.invalid', port: 1080 } }],
+  ['a missing proxy identity', { proxyConfig: { type: 'socks5', host: '', port: 0, identityId: 'missing-identity' } }],
+  ['an incomplete proxy identity', { proxyConfig: { type: 'socks5', host: '', port: 0, identityId: 'incomplete-identity' } }],
+] as const) {
+  test(`Telnet adding ${label} cannot bypass actual starter rejection through reuse`, async (t) => {
+    const original = host({ protocol: 'telnet' });
+    const api = await harness(original, { identities: [{ id: 'incomplete-identity', label: 'Incomplete', username: 'proxy-user', authMethod: 'password', created: 0 }] });
+    t.after(api.close);
+    assert.equal((await api.find())?.sessionId, 'tab');
+    await api.update({ host: { ...original, ...proxy } });
+    assert.equal(await api.find(), undefined);
+    await api.update({ host: { ...original, label: 'Renamed without a proxy' } });
+    assert.equal((await api.find())?.sessionId, 'tab');
+  });
+}
+
+test('Telnet inheriting a proxy profile cannot reuse its previous direct session', async (t) => {
+  const original = host({ protocol: 'telnet', group: 'prod/web' });
+  const groupConfigs: GroupConfig[] = [];
+  const proxyProfiles = [{ id: 'group-proxy', label: 'Proxy', createdAt: 0, config: { type: 'socks5' as const, host: 'proxy.invalid', port: 1080 } }];
+  const resolveEffectiveHost = (candidate: Host) => resolveEffectiveTerminalHost({ host: candidate, groupConfigs, proxyProfiles });
+  const api = await harness(original, { resolveEffectiveHost });
+  t.after(api.close);
+  assert.equal((await api.find())?.sessionId, 'tab');
+  groupConfigs.push({ path: 'prod', proxyProfileId: 'group-proxy' });
+  assert.equal(resolveEffectiveHost(original).proxyConfig?.host, 'proxy.invalid');
+  await api.update({ host: { ...original } });
+  assert.equal(await api.find(), undefined);
+});
+
+for (const owner of ['saved', 'global'] as const) {
+  for (const [field, changed] of [
+    ['localShell', '/bin/zsh'], ['localShellArgs', ['--norc']], ['localStartDir', '/project-b'],
+  ] as const) {
+    test(`local launch snapshot survives ${owner} ${field} edits and unchanged defaults reuse`, async (t) => {
+      const settings = { localShell: '/bin/bash', localShellArgs: undefined as string[] | undefined, localStartDir: '/project-a' };
+      const original = host({ protocol: 'local', hostname: 'localhost', ...(owner === 'saved' ? settings : {}) });
+      const context = {
+        terminalSettings: settings,
+        resolveShellSetting: (command: string, _shells: DiscoveredShell[], args?: string[]) => ({ command, args }),
+      };
+      const resolveEffectiveHost = (candidate: Host) => resolveHostDefaultLocalShell(candidate, context);
+      const launched = { ...createHostTerminalSession('launched', resolveEffectiveHost(original)), status: 'connected' as const };
+      const api = await harness(original, { sessions: [launched], resolveEffectiveHost });
+      t.after(api.close);
+      assert.equal((await api.find())?.sessionId, launched.id, 'undefined settings args and [] snapshot launch identically');
+      const edited = owner === 'saved' ? { ...original, [field]: changed } : original;
+      if (owner === 'global') Object.assign(settings, { [field]: changed });
+      await api.update({ host: edited });
+      assert.equal(await api.find(), undefined, 'an edited launch must not return the old process');
+      const copy = resolveTerminalSessionHost({ session: launched, hosts: [edited], groupConfigs: [], proxyProfiles: [], localOs: 'linux', defaultLocalShell: context });
+      assert.equal(copy.localShell, '/bin/bash');
+      assert.deepEqual(copy.localShellArgs, []);
+      assert.equal(copy.localStartDir, '/project-a');
+    });
+  }
+}
+
+test('home and backend-default snapshots do not inherit later global or saved settings', async (t) => {
+  const original = host({ protocol: 'local', hostname: 'localhost' });
+  const settings: { localShell?: string; localStartDir?: string } = {};
+  const context = { terminalSettings: settings, resolveShellSetting: (command: string) => command ? { command } : null };
+  const resolveEffectiveHost = (candidate: Host) => resolveHostDefaultLocalShell(candidate, context);
+  const launched = { ...createHostTerminalSession('home-default', resolveEffectiveHost(original)), status: 'connected' as const };
+  assert.equal(launched.localShell, '');
+  assert.equal(launched.localStartDir, '~');
+  const api = await harness(original, { sessions: [launched], resolveEffectiveHost });
+  t.after(api.close);
+  assert.equal((await api.find())?.sessionId, launched.id);
+  Object.assign(settings, { localShell: '/bin/bash', localStartDir: '/new-global' });
+  const edited = { ...original, localShell: '/bin/zsh', localStartDir: '/new-saved' };
+  await api.update({ host: edited });
+  assert.equal(await api.find(), undefined);
+  const copied = resolveTerminalSessionHost({ session: launched, hosts: [edited], groupConfigs: [], proxyProfiles: [], localOs: 'linux', defaultLocalShell: context });
+  assert.equal(copied.localShell, '', 'empty captured executable still requests backend default');
+  assert.equal(copied.localStartDir, '~', 'home remains home after a new global directory');
+});
+
+test('saved discovery IDs resolve before snapshot while backend default stays independent of discovery', async (t) => {
+  const saved = host({ protocol: 'local', hostname: 'localhost', localShell: 'bash' });
+  const context = {
+    discoveredShells: [{ id: 'bash', name: 'Bash', command: '/bin/bash', args: ['-l'], icon: 'bash', isDefault: true }],
+    resolveShellSetting: (command: string) => command === 'bash' ? { command: '/bin/bash', args: ['-l'] } : null,
+  };
+  const resolveEffectiveHost = (candidate: Host) => resolveHostDefaultLocalShell(candidate, context);
+  const launched = { ...createHostTerminalSession('discovered', resolveEffectiveHost(saved)), status: 'connected' as const };
+  assert.equal(launched.localShell, '/bin/bash');
+  const api = await harness(saved, { sessions: [launched], resolveEffectiveHost });
+  t.after(api.close);
+  assert.equal((await api.find())?.sessionId, launched.id);
+  const defaultLaunch = resolveEffectiveHost({ ...saved, localShell: undefined });
+  assert.equal(defaultLaunch.localShell, '');
+  assert.equal(defaultLaunch.localShellArgs, undefined);
+});
+
+for (const discovered of [
+  { id: 'bin-bash', name: 'Bash', command: '/bin/bash', args: ['-l'], icon: 'bash' },
+  { id: 'wsl-ubuntu', name: 'Ubuntu', command: 'C:\\Windows\\System32\\wsl.exe', args: ['-d', 'Ubuntu'], icon: 'ubuntu' },
+]) {
+  for (const owner of ['saved', 'global'] as const) {
+    test(`cold ${owner} ${discovered.id} reuses after discovery without masking edits`, async (t) => {
+      const settings = { localShell: discovered.id, localStartDir: '/project-a' };
+      const original = host({ protocol: 'local', hostname: 'localhost', ...(owner === 'saved' ? settings : {}) });
+      const context = { terminalSettings: settings, discoveredShells: [] as DiscoveredShell[], resolveShellSetting };
+      const resolveEffectiveHost = (candidate: Host) => resolveHostDefaultLocalShell(candidate, context);
+      const launched = { ...createHostTerminalSession('cold', resolveEffectiveHost(original)), status: 'connected' as const };
+      assert.equal(launched.localShell, discovered.id);
+      const api = await harness(original, { sessions: [launched], resolveEffectiveHost });
+      t.after(api.close);
+      assert.equal((await api.find())?.sessionId, launched.id);
+      context.discoveredShells = [discovered];
+      await api.update({ host: { ...original } });
+      assert.equal((await api.find())?.sessionId, launched.id, 'discovery resolves the same executable and default arguments');
+      const edited = { ...original, localShell: discovered.command, localShellArgs: ['--edited'], localStartDir: '/project-b' };
+      await api.update({ host: edited });
+      assert.equal(await api.find(), undefined, 'a real path/argument/directory edit still opens a new session');
+      const copy = resolveTerminalSessionHost({ session: launched, hosts: [edited], groupConfigs: [], proxyProfiles: [], localOs: 'linux', defaultLocalShell: context });
+      assert.equal(copy.localShell, discovered.id);
+      assert.deepEqual(copy.localShellArgs, []);
+      assert.equal(copy.localStartDir, '/project-a');
+    });
+  }
+}
+
+test('discovery does not replace an explicit executable or its custom arguments with an alias', async (t) => {
+  const original = host({ protocol: 'local', hostname: 'localhost', localShell: '/bin/bash', localShellArgs: ['--norc'] });
+  const context = { discoveredShells: [] as DiscoveredShell[], resolveShellSetting };
+  const resolveEffectiveHost = (candidate: Host) => resolveHostDefaultLocalShell(candidate, context);
+  const api = await harness(original, { resolveEffectiveHost });
+  t.after(api.close);
+  context.discoveredShells = [{ id: 'bin-bash', name: 'Bash', command: '/bin/bash', args: ['-l'], icon: 'bash' }];
+  await api.update({ host: { ...original } });
+  assert.equal((await api.find())?.sessionId, 'tab');
+  await api.update({ host: { ...original, localShell: 'bin-bash', localShellArgs: undefined } });
+  assert.equal(await api.find(), undefined, 'selecting discovered login defaults changes the actual launch');
+});

application/state/useHostOpenSessionReuse.ts

@@ -0,0 +1,149 @@
+import { useCallback, useLayoutEffect, useRef } from 'react';
+import type { Host, Identity, SSHKey, TerminalSession } from '../../domain/models';
+import { findReusableHostSession } from '../../domain/hostOpenSession';
+import { resolveTelnetPassword, resolveTelnetPort, resolveTelnetUsername } from '../../domain/host';
+import { isEncryptedCredentialPlaceholder, sanitizeCredentialValue } from '../../domain/credentials';
+import { resolveEffectiveTerminalProtocol } from '../../domain/terminalProtocol';
+import { findIncompleteProxyIdentityId, findMissingProxyIdentityId, hasUsableProxyConfig } from '../../domain/proxyProfiles';
+import { buildSftpHostCredentials } from './sftp/useSftpHostCredentials';
+import { buildTransferPoolKey } from './sftp/transferConnectionPool';
+import { createHostTerminalSession } from './sessionFactories';
+
+type HostOpenSessionReuseInput = {
+  sessions: TerminalSession[];
+  hosts: Host[];
+  keys: SSHKey[];
+  identities: Identity[];
+  resolveEffectiveHost: (host: Host) => Host;
+};
+
+type OpeningConnection = { localHost: Host } | { key: Promise<string | undefined> };
+
+/** Retain the opening connection identity, never credentials in session storage. */
+export function useHostOpenSessionReuse({ sessions, hosts, keys, identities, resolveEffectiveHost }: HostOpenSessionReuseInput) {
+  const openingKeys = useRef(new Map<string, OpeningConnection>());
+  const connectionKey = useCallback((host: Host) => {
+    const protocol = resolveEffectiveTerminalProtocol(host);
+    if (protocol === 'local') {
+      const options = {
+        hostname: host.hostname,
+        username: '',
+        localShell: host.localShell || undefined,
+        // The renderer starter omits both absent and empty args so the
+        // backend chooses its discovered/login defaults for either form.
+        localShellArgs: host.localShellArgs?.length ? host.localShellArgs : undefined,
+        localStartDir: host.localStartDir || '~',
+      };
+      return buildTransferPoolKey({ hostname: host.hostname, hostId: host.id, protocol, connectionOptions: options });
+    }
+    if (protocol === 'telnet') {
+      // The actual Telnet starter rejects these settings before connecting.
+      if ((host.proxyProfileId && !host.proxyConfig)
+        || findMissingProxyIdentityId(host.proxyConfig, identities)
+        || findIncompleteProxyIdentityId(host.proxyConfig, identities)
+        || hasUsableProxyConfig(host.proxyConfig)) {
+        throw new Error('Telnet proxy configuration cannot be used');
+      }
+      // Match the actual Telnet starter, including explicit empty overrides.
+      const identity = host.telnetIdentityId ? identities.find((item) => item.id === host.telnetIdentityId) : undefined;
+      if (host.telnetIdentityId && (!identity?.username?.trim() || identity.password === undefined)) {
+        throw new Error('Telnet identity is missing or incomplete');
+      }
+      const rawPassword = identity ? identity.password : resolveTelnetPassword(host);
+      if (isEncryptedCredentialPlaceholder(rawPassword)) throw new Error('Telnet credentials are unavailable');
+      const options = {
+        hostname: host.hostname,
+        port: resolveTelnetPort(host),
+        username: identity ? identity.username?.trim() : resolveTelnetUsername(host),
+        password: sanitizeCredentialValue(rawPassword),
+      };
+      return buildTransferPoolKey({ ...options, hostId: host.id, protocol, connectionOptions: options });
+    }
+    // Reuse the existing credential/chain expansion and transport identity
+    // comparison. Presentation names and SFTP-only choices do not change a
+    // terminal's destination or login.
+    if (protocol === 'serial' && isEncryptedCredentialPlaceholder(host.password)) throw new Error('Serial credentials are unavailable');
+    const options = buildSftpHostCredentials({
+      host, hosts: hosts.map(resolveEffectiveHost), keys, identities,
+    });
+    delete options.sudo;
+    delete options.fileProtocol;
+    for (const hop of options.jumpHosts ?? []) delete hop.label;
+    const connectionOptions = {
+      ...options,
+      protocol,
+      moshEnabled: host.moshEnabled,
+      moshServerPath: host.moshServerPath,
+      etEnabled: host.etEnabled,
+      etPort: host.etPort,
+      etJumpPorts: protocol === 'et'
+        ? host.hostChain?.hostIds.map((id) => hosts.find((item) => item.id === id)).map((hop) => hop && (resolveEffectiveHost(hop).etPort ?? 2022))
+        : undefined,
+      pluginConnection: host.pluginConnection,
+      serialConfig: protocol === 'serial' ? createHostTerminalSession('', host).serialConfig : undefined,
+      serialLogin: protocol === 'serial' ? { username: host.username?.trim(), password: sanitizeCredentialValue(host.password) } : undefined,
+      agentForwarding: host.agentForwarding,
+      x11Forwarding: host.x11Forwarding,
+    };
+    return buildTransferPoolKey({ ...options, protocol: connectionOptions.protocol, connectionOptions });
+  }, [hosts, keys, identities, resolveEffectiveHost]);
+
+  useLayoutEffect(() => {
+    const liveIds = new Set(sessions.map((session) => session.id));
+    for (const id of openingKeys.current.keys()) {
+      if (!liveIds.has(id)) openingKeys.current.delete(id);
+    }
+    for (const session of sessions) {
+      if (openingKeys.current.has(session.id) || session.restoreState) continue;
+      const host = hosts.find((candidate) => candidate.id === session.hostId);
+      if (!host) continue;
+      try {
+        const effectiveHost = resolveEffectiveHost(host);
+        const openingHost = {
+          ...effectiveHost,
+          hostname: session.hostname,
+          username: session.protocol === 'serial' ? resolveEffectiveHost(host).username : session.username,
+          port: session.port ?? host.port,
+          protocol: session.protocol ?? host.protocol,
+          moshEnabled: session.moshEnabled ?? host.moshEnabled,
+          etEnabled: session.etEnabled ?? host.etEnabled,
+          serialConfig: session.serialConfig ?? host.serialConfig,
+          pluginConnection: session.pluginConnection ?? host.pluginConnection,
+          localShell: session.localShell ?? effectiveHost.localShell,
+          localShellArgs: session.localShellArgs ?? effectiveHost.localShellArgs,
+          localStartDir: session.localStartDir ?? effectiveHost.localStartDir,
+        };
+        // Local IDs may only resolve after renderer discovery completes. Keep
+        // the opening settings so that later discovery can identify the same
+        // executable without replacing them with edited vault/global settings.
+        openingKeys.current.set(session.id, resolveEffectiveTerminalProtocol(openingHost) === 'local'
+          ? { localHost: openingHost }
+          : { key: connectionKey(openingHost).catch(() => undefined) });
+      } catch {
+        openingKeys.current.set(session.id, { key: Promise.resolve(undefined) });
+      }
+    }
+  }, [sessions, hosts, connectionKey, resolveEffectiveHost]);
+
+  return useCallback(async (hostId: string) => {
+    const host = hosts.find((candidate) => candidate.id === hostId);
+    if (!host) return undefined;
+    try {
+      const requestedKey = await connectionKey(resolveEffectiveHost(host));
+      const matches = await Promise.all(sessions.map(async (session) => {
+        if (session.hostId !== hostId) return undefined;
+        const opening = openingKeys.current.get(session.id);
+        const openingKey = opening && ('localHost' in opening
+          // An explicit empty selector means backend default, not today's
+          // global setting. Nonempty captured IDs can safely resolve now.
+          ? connectionKey(opening.localHost.localShell ? resolveEffectiveHost(opening.localHost) : opening.localHost)
+          : opening.key);
+        return await openingKey === requestedKey ? session : undefined;
+      }));
+      return findReusableHostSession(matches.filter((session) => session !== undefined), hostId);
+    } catch {
+      // An unresolved/changed credential must never select an old transport.
+      return undefined;
+    }
+  }, [hosts, sessions, connectionKey, resolveEffectiveHost]);
+}

application/state/useSessionHistorySearch.ts

@@ -0,0 +1,24 @@
+import { useEffect, useMemo } from 'react';
+import {
+  createSessionHistorySearch,
+  type SessionHistorySearch,
+} from './sessionHistorySearch';
+
+/**
+ * Owns one search instance per mounted session history drawer.
+ *
+ * The search index cache is bound to this instance (not module scope), so
+ * several concurrently mounted drawers — one per terminal tab — each keep
+ * their own indexes: pruning in one drawer never drops another drawer's
+ * entries, and the unmount below releases only this drawer's store instead of
+ * discarding the shared cache for every drawer. Cache keys are the session
+ * objects themselves, so clearing on unmount drops all strong session
+ * references together with the retained haystack characters.
+ */
+export function useSessionHistorySearch(): SessionHistorySearch {
+  const search = useMemo(() => createSessionHistorySearch(), []);
+  useEffect(() => () => {
+    search.clearSessionHistorySearchCache();
+  }, [search]);
+  return search;
+}

application/state/useSessionState.ts

@@ -1098,17 +1098,12 @@ export const useSessionState = ({
     if (targetHosts.length === 0) return;
     const resolvedCommand = commandOverride ?? snippet.command;
 
-    // Create sessions for each target host
-    const newSessions: TerminalSession[] = targetHosts.map(host => ({
-      id: crypto.randomUUID(),
-      hostId: host.id,
-      hostLabel: host.label,
-      hostname: host.hostname,
-      username: host.username,
-      status: 'connecting' as const,
-      charset: host.charset,
-      // workspaceId will be set after workspace is created
-    }));
+    // Create sessions for each target host. createHostTerminalSession copies
+    // protocol, shellType, and local-shell metadata, so local vault hosts keep
+    // their transport info (session consumers treat a missing protocol as SSH).
+    const newSessions: TerminalSession[] = targetHosts.map(host =>
+      createHostTerminalSession(crypto.randomUUID(), host),
+    );
 
     const sessionIds = newSessions.map(s => s.id);
     

application/state/useSettingsState.ts

@@ -151,6 +151,7 @@ import {
   isValidUiFontId,
   isValidUiThemeId,
   migrateIncomingTerminalFontId,
+  migrateMaterializedAutoCloseOnExitDefault,
   readStoredString,
   serializeTerminalSettings,
   type HostClickBehavior,
@@ -355,6 +356,9 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     passwordVerifier: null,
   });
   const [terminalSettings, setTerminalSettingsState] = useState<TerminalSettings>(() => {
+    // One-time reset of the pre-flip materialized autoCloseOnExit: true before
+    // it is ingested; afterwards stored values are the user's own and win.
+    migrateMaterializedAutoCloseOnExitDefault();
     const stored = localStorageAdapter.read<TerminalSettings>(STORAGE_KEY_TERM_SETTINGS);
     return normalizeTerminalSettings(stored);
   });

application/state/useVaultAgentBridge.ts

@@ -53,6 +53,7 @@ export interface UseVaultAgentBridgeInput {
   stopTunnel: VaultAgentApiDeps['stopTunnel'];
   stopRuleTunnels: VaultAgentApiDeps['stopRuleTunnels'];
   openHost?: VaultAgentApiDeps['openHost'];
+  findExistingSessionForHost?: VaultAgentApiDeps['findExistingSessionForHost'];
   closeSession?: VaultAgentApiDeps['closeSession'];
   getScriptSessionMeta?: (sessionId: string) => Pick<TerminalSession, 'status' | 'customName' | 'hostLabel' | 'hostname' | 'username'> | undefined;
 }
@@ -271,6 +272,7 @@ export function useVaultAgentBridge(input: UseVaultAgentBridgeInput): void {
         openHost: current.openHost
           ? (host, isExternalMcpCall) => current.openHost!(host, isExternalMcpCall)
           : undefined,
+        findExistingSessionForHost: current.findExistingSessionForHost,
         closeSession: current.closeSession
           ? (sessionId) => current.closeSession!(sessionId)
           : undefined,

application/state/useVaultState.ts

@@ -80,6 +80,7 @@ import {
   registerNotesActions,
 } from "./notesStore";
 import { commitVaultNotesWrite } from "./vaultNotesPersistence";
+import { rebasePendingVaultNotes } from "../../domain/vaultNotesReconciliation";
 import { publishShellHistorySnapshot } from "./shellHistoryStore";
 import { setVaultInitialized } from "./vaultInitStore";
 import { notify } from "../notification";
@@ -306,6 +307,12 @@ export const useVaultState = () => {
   const snippetsRef = useRef<Snippet[]>([]);
   const groupConfigsRef = useRef<GroupConfig[]>([]);
   const notesRef = useRef<VaultNote[]>([]);
+  const notesStorageRef = useRef<VaultNote[]>([]);
+  // An optimistic React echo is not a persistence acknowledgement. Keep this
+  // owner until that exact generation has successfully reached storage.
+  const notesPendingRef = useRef<VaultNote[] | null>(null);
+  // Failed clear/import keeps full-snapshot ownership across later local edits.
+  const notesPendingReplaceRef = useRef(false);
   const noteGroupsRef = useRef<string[]>([]);
   const notesPersistFailureNotifiedAtRef = useRef(0);
   customGroupsRef.current = customGroups;
@@ -834,17 +841,37 @@ export const useVaultState = () => {
     localStorageAdapter.write(STORAGE_KEY_SNIPPET_PACKAGES, data);
   }, []);
 
-  const updateNotes = useCallback((data: Partial<VaultNote>[]) => {
+  const updateNotes = useCallback((data: Partial<VaultNote>[], options?: { replace?: boolean }) => {
+    const stored = normalizeVaultNotes(localStorageAdapter.read<VaultNote[]>(STORAGE_KEY_NOTES) ?? []);
+    const requested = normalizeVaultNotes(data);
+    // Explicit clear/restore keeps its existing full-snapshot semantics.
+    const replace = options?.replace === true || notesPendingReplaceRef.current;
+    const pending = replace ? requested : rebasePendingVaultNotes({
+      base: notesStorageRef.current,
+      ours: requested,
+      theirs: stored,
+    });
+    notesStorageRef.current = stored;
+    notesPendingRef.current = pending;
+    notesPendingReplaceRef.current = replace;
+    notesRef.current = pending;
     const { notes: cleaned, persisted } = commitVaultNotesWrite({
-      data,
+      data: pending,
       write: (key, value) => localStorageAdapter.write(key, value),
     });
     // Keep the in-session catalog updated so an autosave quota failure does not
     // snap the editor back to stale props and discard the user's draft. Disk
     // may still be behind — surface that explicitly.
-    notesRef.current = cleaned;
-    setNotes(cleaned);
-    publishNotesSnapshot({ notes: cleaned, noteGroups: noteGroupsRef.current });
+    if (notesPendingRef.current === pending) {
+      notesRef.current = cleaned;
+      if (persisted) {
+        notesStorageRef.current = cleaned;
+        notesPendingRef.current = null;
+        notesPendingReplaceRef.current = false;
+      }
+      setNotes(cleaned);
+      publishNotesSnapshot({ notes: cleaned, noteGroups: noteGroupsRef.current });
+    }
     if (!persisted) {
       const now = Date.now();
       // Debounced autosave can hit quota repeatedly; avoid toast spam.
@@ -1163,7 +1190,7 @@ export const useVaultState = () => {
     updateProxyProfiles([]);
     updateSnippets([], { replace: true });
     updateSnippetPackages([]);
-    updateNotes([]);
+    updateNotes([], { replace: true });
     updateNoteGroups([]);
     updateCustomGroups([]);
     updateKnownHosts([]);
@@ -1534,8 +1561,10 @@ export const useVaultState = () => {
 
         if (savedGroups) setCustomGroups(savedGroups);
         if (savedSnippetPackages) setSnippetPackages(savedSnippetPackages);
-        if (savedNotes) {
+        if (savedNotes && notesPendingRef.current === null) {
           const cleanedNotes = normalizeVaultNotes(savedNotes);
+          notesStorageRef.current = cleanedNotes;
+          notesRef.current = cleanedNotes;
           setNotes(cleanedNotes);
           localStorageAdapter.write(STORAGE_KEY_NOTES, cleanedNotes);
         }
@@ -1780,8 +1809,21 @@ export const useVaultState = () => {
       }
 
       if (key === STORAGE_KEY_NOTES) {
-        const next = safeParse<VaultNote[]>(event.newValue) ?? [];
-        setNotes(normalizeVaultNotes(next));
+        // Like snippets, ignore queued events for a snapshot no longer on disk.
+        if (event.newValue !== localStorageAdapter.readString(STORAGE_KEY_NOTES)) return;
+        // Only a successful current write can release an outstanding replacement.
+        if (notesPendingReplaceRef.current) return;
+        const next = normalizeVaultNotes(safeParse<VaultNote[]>(event.newValue) ?? []);
+        const pending = notesPendingRef.current;
+        const visible = pending === null ? next : rebasePendingVaultNotes({
+          base: notesStorageRef.current,
+          ours: pending,
+          theirs: next,
+        });
+        notesStorageRef.current = next;
+        if (pending !== null) notesPendingRef.current = visible;
+        notesRef.current = visible;
+        setNotes(visible);
         return;
       }
 
@@ -1952,7 +1994,7 @@ export const useVaultState = () => {
       }
       if (payload.customGroups) updateCustomGroups(payload.customGroups);
       if (payload.snippetPackages) updateSnippetPackages(payload.snippetPackages);
-      if (payload.notes) updateNotes(payload.notes);
+      if (payload.notes) updateNotes(payload.notes, { replace: true });
       if (payload.noteGroups) updateNoteGroups(payload.noteGroups);
       if (payload.knownHosts) updateKnownHosts(payload.knownHosts);
       if (Array.isArray(payload.groupConfigs)) encryptedWrites.push(updateGroupConfigs(payload.groupConfigs));

application/syncPayload.test.ts

@@ -1667,6 +1667,50 @@ test("terminal auto-close preference survives sync round-trip", async () => {
   assert.equal(restored.autoCloseOnExit, false);
 });
 
+test("inbound sync does not resurrect the materialized auto-close default after the marker", async () => {
+  localStorage.setItem(storageKeys.STORAGE_KEY_TERM_AUTO_CLOSE_EXIT_MIGRATED, "true");
+  try {
+    localStorage.setItem(
+      storageKeys.STORAGE_KEY_TERM_SETTINGS,
+      JSON.stringify({ autoCloseOnExit: false, scrollback: 3000 }),
+    );
+
+    await applySyncPayload({
+      hosts: [],
+      keys: [],
+      identities: [],
+      snippets: [],
+      customGroups: [],
+      syncedAt: 1,
+      settings: { terminalSettings: { autoCloseOnExit: true } },
+    }, { importVaultData: () => {} });
+
+    const resurrected = JSON.parse(localStorage.getItem(storageKeys.STORAGE_KEY_TERM_SETTINGS)!);
+    assert.equal(resurrected.autoCloseOnExit, false);
+    assert.equal(resurrected.scrollback, 3000);
+
+    // An explicit opt-in made after the migration round-trips with a marker.
+    localStorage.setItem(
+      storageKeys.STORAGE_KEY_TERM_SETTINGS,
+      JSON.stringify({ autoCloseOnExit: true, scrollback: 3000 }),
+    );
+    const optedIn = buildSyncPayload(vault());
+    assert.equal(optedIn.settings?.autoCloseOnExitDefaultMigrated, true);
+    assert.equal(optedIn.settings?.terminalSettings?.autoCloseOnExit, true);
+
+    localStorage.setItem(
+      storageKeys.STORAGE_KEY_TERM_SETTINGS,
+      JSON.stringify({ autoCloseOnExit: false, scrollback: 3000 }),
+    );
+    await applySyncPayload(optedIn, { importVaultData: () => {} });
+    const restoredChoice = JSON.parse(localStorage.getItem(storageKeys.STORAGE_KEY_TERM_SETTINGS)!);
+    assert.equal(restoredChoice.autoCloseOnExit, true);
+    assert.equal(localStorage.getItem(storageKeys.STORAGE_KEY_TERM_AUTO_CLOSE_EXIT_MIGRATED), "true");
+  } finally {
+    localStorage.removeItem(storageKeys.STORAGE_KEY_TERM_AUTO_CLOSE_EXIT_MIGRATED);
+  }
+});
+
 test("terminal disconnected notice preference survives sync round-trip", async () => {
   localStorage.setItem(
     storageKeys.STORAGE_KEY_TERM_SETTINGS,

application/syncPayload.ts

@@ -25,6 +25,7 @@ import {
   SYNC_PAYLOAD_ENTITY_KEYS,
   SYNC_STORAGE_KEYS,
   hasSyncPayloadEntityData,
+  reconcileInboundAutoCloseOnExit,
   retainLocalHostLastConnectedAt,
   sanitizeHostsForSync,
   type SyncPayload,
@@ -62,6 +63,7 @@ import {
 } from './state/customAccentSync';
 import { isValidHslToken } from './state/settingsStateDefaults';
 import {
+  STORAGE_KEY_TERM_AUTO_CLOSE_EXIT_MIGRATED,
   STORAGE_KEY_THEME,
   STORAGE_KEY_UI_THEME_LIGHT,
   STORAGE_KEY_UI_THEME_DARK,
@@ -505,6 +507,9 @@ export function collectSyncableSettings(): SyncPayload['settings'] {
       if (Object.keys(subset).length > 0) settings.terminalSettings = subset;
     } catch { /* ignore corrupt data */ }
   }
+  if (localStorageAdapter.readBoolean(STORAGE_KEY_TERM_AUTO_CLOSE_EXIT_MIGRATED)) {
+    settings.autoCloseOnExitDefaultMigrated = true;
+  }
 
   // Custom terminal themes
   const customThemesRaw = localStorageAdapter.readString(STORAGE_KEY_CUSTOM_THEMES);
@@ -795,6 +800,23 @@ async function applySyncableSettings(
         ? 'disabled'
         : 'paste';
     }
+    if ('autoCloseOnExit' in settings.terminalSettings) {
+      merged.autoCloseOnExit = reconcileInboundAutoCloseOnExit(
+        settings.terminalSettings.autoCloseOnExit,
+        settings.autoCloseOnExitDefaultMigrated,
+      );
+    }
+    // A legacy true is the old default. A migrated peer's explicit choice must
+    // stick, so record the marker before the next local migration pass.
+    if (
+      settings.autoCloseOnExitDefaultMigrated === true
+      || (
+        settings.terminalSettings.autoCloseOnExit === true
+        && settings.autoCloseOnExitDefaultMigrated !== true
+      )
+    ) {
+      localStorageAdapter.writeBoolean(STORAGE_KEY_TERM_AUTO_CLOSE_EXIT_MIGRATED, true);
+    }
     localStorageAdapter.writeString(STORAGE_KEY_TERM_SETTINGS, JSON.stringify(merged));
   }
 

components/AIChatPanelContent.tsx

@@ -1,5 +1,5 @@
 import React, { type Dispatch, type SetStateAction } from 'react';
-import { History, Plus } from 'lucide-react';
+import { History, Plus, Undo2 } from 'lucide-react';
 import type { AIPermissionMode, AISession, ChatMessage, DiscoveredAgent, ExternalAgentConfig, AgentModelPreset, ProviderConfig, UploadedFile } from '../infrastructure/ai/types';
 import type { Host, VaultNote } from '../types';
 import type { UserSkillOption } from './ai/userSkillsState';
@@ -47,6 +47,8 @@ interface AIChatPanelContentProps {
   activeSessionId: string | null;
   handleSelectSession: (sessionId: string) => void;
   handleDeleteSession: (event: React.MouseEvent, sessionId: string) => void;
+  /** Fork the conversation up to a completed assistant response into a new session. */
+  onForkFromMessage?: (messageId: string) => void;
   messages: ChatMessage[];
   isStreaming: boolean;
   activeCompaction?: import('../application/state/useAgentCompactionUi').ActiveCompactionUi | null;
@@ -55,6 +57,9 @@ interface AIChatPanelContentProps {
   setInputValue: (value: string) => void;
   handleSend: () => void;
   handleCompact: () => void;
+  /** Undo last turn is offered at a safe boundary (never mid-tool / mid-compaction). */
+  canUndoLastTurn?: boolean;
+  handleUndoLastTurn?: () => void;
   canCompact?: boolean;
   handleSteer: () => void;
   handleStop: () => void;
@@ -124,6 +129,7 @@ export const AIChatPanelContent: React.FC<AIChatPanelContentProps> = ({
   activeSessionId,
   handleSelectSession,
   handleDeleteSession,
+  onForkFromMessage,
   messages,
   isStreaming,
   activeCompaction = null,
@@ -132,6 +138,8 @@ export const AIChatPanelContent: React.FC<AIChatPanelContentProps> = ({
   setInputValue,
   handleSend,
   handleCompact,
+  canUndoLastTurn = false,
+  handleUndoLastTurn,
   canCompact = false,
   handleSteer,
   handleStop,
@@ -232,6 +240,23 @@ export const AIChatPanelContent: React.FC<AIChatPanelContentProps> = ({
               onManageAgents={handleOpenSettings}
             />
             <div className="flex items-center gap-0.5">
+              {handleUndoLastTurn && (
+                <Tooltip>
+                  <TooltipTrigger asChild>
+                    <Button
+                      variant="ghost"
+                      size="icon"
+                      className="h-6 w-6 rounded-md text-muted-foreground/62 hover:bg-white/[0.05] hover:text-foreground"
+                      aria-label={t('ai.chat.undoLastTurn')}
+                      disabled={sending || isStreaming || !canUndoLastTurn}
+                      onClick={handleUndoLastTurn}
+                    >
+                      <Undo2 size={12} />
+                    </Button>
+                  </TooltipTrigger>
+                  <TooltipContent>{t('ai.chat.undoLastTurn')}</TooltipContent>
+                </Tooltip>
+              )}
               <ConversationExport
                 session={activeSession}
                 onExport={handleExport}
@@ -291,6 +316,8 @@ export const AIChatPanelContent: React.FC<AIChatPanelContentProps> = ({
                 isStreaming={isStreaming}
                 activeSessionId={activeSessionId}
                 activeCompaction={activeCompaction}
+                contextCompaction={activeSession?.contextCompaction}
+                onForkFromMessage={onForkFromMessage}
                 notes={notes}
                 hosts={hosts}
                 onOpenVaultNote={onOpenVaultNote}

components/AIChatSessionHistoryDrawer.test.tsx

@@ -0,0 +1,126 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import React from "react";
+
+import type { AISession } from "../infrastructure/ai/types.ts";
+import { MESSAGES_BY_LOCALE } from "../application/i18n/messages.ts";
+import { createDomRenderer, dispatchDomEvent, installDomEnvironment } from "./test-support/renderReactDom.tsx";
+
+test("history drawer filters, pages, clears and explains the bounded search in every locale", async () => {
+  const dom = installDomEnvironment();
+  const { SessionHistoryDrawer } = await import("./AIChatSessionHistoryDrawer.tsx");
+  const { I18nProvider } = await import("../application/i18n/I18nProvider.tsx");
+  const { TooltipProvider } = await import("./ui/tooltip.tsx");
+  const renderer = await createDomRenderer(dom.document);
+  const sessions: AISession[] = Array.from({ length: 141 }, (_, i) => ({
+    id: `s-${i}`,
+    title: `Session ${i}`,
+    agentId: "catty",
+    scope: { type: "terminal", targetId: "terminal-1" },
+    messages: [{
+      id: `m-${i}`, role: "user", timestamp: 0,
+      content: i === 140 ? "needle [prod].json" : "ordinary content",
+    }],
+    createdAt: 0,
+    updatedAt: 0,
+  }));
+  const selected: string[] = [];
+  const deleted: string[] = [];
+  let closed = 0;
+  const render = (items = sessions, locale = "en") => renderer.render(
+    <I18nProvider locale={locale}>
+      <TooltipProvider>
+        <SessionHistoryDrawer
+          sessions={items}
+          activeSessionId="s-140"
+          onSelect={(id) => selected.push(id)}
+          onDelete={(event, id) => { event.stopPropagation(); deleted.push(id); }}
+          onClose={() => { closed += 1; }}
+        />
+      </TooltipProvider>
+    </I18nProvider>,
+  );
+  const rows = () => renderer.container.querySelectorAll('[role="button"]');
+  const click = async (element: Element | null | undefined) => {
+    assert.ok(element);
+    await dispatchDomEvent(element, new dom.window.MouseEvent("click", { bubbles: true }));
+  };
+  const enterQuery = async (query: string) => {
+    const input = renderer.container.querySelector("input");
+    assert.ok(input);
+    const setValue = Object.getOwnPropertyDescriptor(dom.window.HTMLInputElement.prototype, "value")!.set!;
+    setValue.call(input, query);
+    await dispatchDomEvent(input, new dom.window.Event("input", { bubbles: true }));
+  };
+  const loadMore = () => [...renderer.container.querySelectorAll("button")]
+    .find((button) => button.textContent?.includes("Load more"));
+
+  try {
+    await render();
+    assert.equal(rows().length, 80);
+    assert.match(loadMore()?.textContent ?? "", /61/);
+    await click(loadMore());
+    assert.equal(rows().length, 140);
+    await enterQuery("[prod].json");
+    assert.equal(rows().length, 1);
+    assert.match(rows()[0].textContent ?? "", /Session 140/);
+    assert.equal(loadMore(), undefined);
+    await click(rows()[0]);
+    await dispatchDomEvent(rows()[0], new dom.window.KeyboardEvent("keydown", { key: "Enter", bubbles: true }));
+    await click(rows()[0].querySelector("button"));
+    assert.deepEqual(selected, ["s-140", "s-140"]);
+    assert.deepEqual(deleted, ["s-140"]);
+
+    // A pasted suffix must not remain visible while the matcher silently
+    // ignores it: the controlled input and search accept the same prefix.
+    const pastedQuery = "needle ".repeat(36) + "needle absent-tail";
+    await enterQuery(pastedQuery);
+    const boundedInput = renderer.container.querySelector("input")!;
+    assert.equal(boundedInput.value, pastedQuery.slice(0, 256));
+    assert.equal(boundedInput.maxLength, 256);
+    assert.ok(!boundedInput.value.includes("absent-tail"));
+    assert.equal(rows().length, 1);
+    assert.match(rows()[0].textContent ?? "", /Session 140/);
+    await enterQuery("needle absent-tail");
+    assert.equal(boundedInput.value, "needle absent-tail");
+    assert.equal(rows().length, 0, "every visible query token must affect matching");
+    await enterQuery("x".repeat(255) + "\u{1f63a}");
+    assert.equal(boundedInput.value, "x".repeat(255), "do not retain half a surrogate pair");
+
+    await enterQuery("[](){}");
+    assert.equal(rows().length, 0);
+    assert.match(renderer.container.textContent ?? "", /No matches in titles or recent retained content/);
+    assert.match(renderer.container.textContent ?? "", /prioritizing newer messages and entries/);
+    assert.match(renderer.container.textContent ?? "", /only a limited portion at the beginning is searched/);
+    assert.match(renderer.container.textContent ?? "", /not full-text search/);
+    await click(renderer.container.querySelector("input")?.parentElement?.querySelector("button"));
+    assert.equal(renderer.container.querySelector("input")?.value, "");
+    assert.equal(rows().length, 80);
+    assert.match(loadMore()?.textContent ?? "", /61/);
+    await enterQuery("  \t");
+    assert.equal(rows().length, 80);
+    await click(renderer.container.querySelector("button"));
+    assert.equal(closed, 1);
+
+    for (const locale of ["en", "zh-CN", "zh-TW", "es", "ru"]) {
+      await render(sessions, locale);
+      await enterQuery("no-such-content");
+      const messages = MESSAGES_BY_LOCALE[locale];
+      const input = renderer.container.querySelector("input")!;
+      const hint = dom.document.getElementById(input.getAttribute("aria-describedby")!);
+      for (const key of ["ai.chat.searchSessions", "ai.chat.searchSessionsHint", "ai.chat.noMatchingSessions"]) {
+        assert.ok(messages[key], `${locale} is missing ${key}`);
+      }
+      assert.equal(input.placeholder, messages["ai.chat.searchSessions"]);
+      assert.equal(input.getAttribute("aria-label"), messages["ai.chat.searchSessions"]);
+      assert.equal(hint?.textContent, messages["ai.chat.searchSessionsHint"]);
+      assert.ok(renderer.container.textContent?.includes(messages["ai.chat.noMatchingSessions"]));
+      await render([], locale);
+      assert.ok(renderer.container.textContent?.includes(messages["ai.chat.noSessions"]));
+      assert.ok(!renderer.container.textContent?.includes(messages["ai.chat.noMatchingSessions"]));
+    }
+  } finally {
+    await renderer.unmount();
+    dom.cleanup();
+  }
+});

components/AIChatSessionHistoryDrawer.tsx

@@ -1,11 +1,14 @@
-import React, { useEffect, useState } from 'react';
-import { Trash2, X } from 'lucide-react';
+import React, { useEffect, useId, useRef, useState } from 'react';
+import { Search, Trash2, X } from 'lucide-react';
 import type { AISession } from '../infrastructure/ai/types';
 import { useI18n } from '../application/i18n/I18nProvider';
 import { cn } from '../lib/utils';
+import { MAX_SEARCH_QUERY_LENGTH, truncateQueryForMatch } from '../lib/searchMatcher';
+import { Input } from './ui/input';
 import { ScrollArea } from './ui/scroll-area';
 import { Tooltip, TooltipContent, TooltipTrigger } from './ui/tooltip';
 import { SESSION_HISTORY_ROW_CLASSNAMES } from './ai/sessionHistoryLayout';
+import { useSessionHistorySearch } from '../application/state/useSessionHistorySearch';
 
 // -------------------------------------------------------------------
 // Session History Drawer
@@ -31,13 +34,28 @@ export const SessionHistoryDrawer: React.FC<SessionHistoryDrawerProps> = ({
 }) => {
   const { t } = useI18n();
   const [renderCount, setRenderCount] = useState(SESSION_RENDER_BATCH);
+  const [searchQuery, setSearchQuery] = useState('');
+  const searchHintId = useId();
+  const searchInputRef = useRef<HTMLInputElement>(null);
+  // One cache instance per mounted drawer: caches of concurrently mounted
+  // drawers stay independent (no shared state to prune or discard across tabs).
+  const search = useSessionHistorySearch();
 
+  const filteredSessions = React.useMemo(
+    // The localized fallback below is displayed for untitled sessions
+    // (row label), so it must be indexed for search as the displayed title.
+    () => search.filterSessionHistory(sessions, searchQuery, { untitledLabel: t('ai.chat.untitled') }),
+    [sessions, searchQuery, t, search],
+  );
+
+  // Reset the render batch when the list scope or query changes so matching
+  // sessions are never hidden behind stale paging.
   useEffect(() => {
     setRenderCount(SESSION_RENDER_BATCH);
-  }, [sessions]);
+  }, [sessions, searchQuery]);
 
-  const displayedSessions = sessions.slice(0, renderCount);
-  const hiddenSessionCount = Math.max(0, sessions.length - renderCount);
+  const displayedSessions = filteredSessions.slice(0, renderCount);
+  const hiddenSessionCount = Math.max(0, filteredSessions.length - renderCount);
 
   return (
     <div className="flex-1 flex flex-col min-h-0">
@@ -50,6 +68,41 @@ export const SessionHistoryDrawer: React.FC<SessionHistoryDrawerProps> = ({
           <X size={14} />
         </button>
       </div>
+      <div className="px-3 py-2 shrink-0 border-b border-border/30">
+        <div className="relative">
+          <Search
+            size={13}
+            className="absolute left-2.5 top-1/2 -translate-y-1/2 text-muted-foreground/50 pointer-events-none"
+          />
+          <Input
+            ref={searchInputRef}
+            type="text"
+            value={searchQuery}
+            maxLength={MAX_SEARCH_QUERY_LENGTH}
+            placeholder={t('ai.chat.searchSessions')}
+            aria-label={t('ai.chat.searchSessions')}
+            aria-describedby={searchHintId}
+            onChange={(event) => setSearchQuery(truncateQueryForMatch(event.target.value))}
+            className="h-8 pl-8 pr-7 text-[12px]"
+          />
+          {searchQuery && (
+            <button
+              type="button"
+              aria-label={t('ai.chat.clearSessionSearch')}
+              onClick={() => {
+                setSearchQuery('');
+                searchInputRef.current?.focus();
+              }}
+              className="absolute right-2 top-1/2 -translate-y-1/2 text-muted-foreground/50 hover:text-muted-foreground transition-colors cursor-pointer"
+            >
+              <X size={12} />
+            </button>
+          )}
+        </div>
+        <p id={searchHintId} className="mt-1.5 text-[11px] text-muted-foreground/60">
+          {t('ai.chat.searchSessionsHint')}
+        </p>
+      </div>
       <ScrollArea className="flex-1">
         <div className="px-3">
           {sessions.length === 0 ? (
@@ -58,6 +111,12 @@ export const SessionHistoryDrawer: React.FC<SessionHistoryDrawerProps> = ({
                 {t('ai.chat.noSessions')}
               </p>
             </div>
+          ) : filteredSessions.length === 0 ? (
+            <div className="py-12 text-center">
+              <p className="text-[13px] text-muted-foreground/40">
+                {t('ai.chat.noMatchingSessions')}
+              </p>
+            </div>
           ) : (
             <>
             {hiddenSessionCount > 0 && (

components/AIChatSidePanel.mountRetention.test.ts

@@ -120,7 +120,9 @@ test('send preflight aborts after the panel unmounts or the scope changes', () =
 test('send preflight locks header agent and new-chat controls', () => {
   const panel = readFileSync(new URL('./AIChatSidePanel.tsx', import.meta.url), 'utf8');
   const content = readFileSync(new URL('./AIChatPanelContent.tsx', import.meta.url), 'utf8');
-  assert.match(panel, /sending=\{isSending\}/);
+  // `sending` also covers an in-flight undo-last-turn so the header controls
+  // (and a quick send) stay locked while the branch materializes.
+  assert.match(panel, /sending=\{isSending \|\| isUndoingLastTurn\}/);
   assert.match(content, /disabled=\{sending\}/);
   const selector = readFileSync(new URL('./ai/AgentSelector.tsx', import.meta.url), 'utf8');
   assert.match(selector, /if \(parked \|\| disabled\) setOpen\(false\)/);

components/AIChatSidePanel.tsx

@@ -65,6 +65,7 @@ import {
 } from '../application/state/useAIChatStreaming';
 import { getScopedHistorySessions } from './ai/scopedHistorySessions';
 import { resolveInheritedAIActiveSessionId } from '../domain/aiWorkspaceScopeInherit';
+import { resolveUndoLastTurnBoundary } from '../domain/aiUndoLastTurn';
 import { aiSessionIdSetEqual, exactScopeAISessionsEqual } from '../domain/aiSessionsForScope';
 import { buildExternalAgentHistoryMessagesForBridge } from './ai/externalAgentHistory';
 import { canSendWithAgent, findEnabledExternalAgent } from './ai/agentSendEligibility';
@@ -269,6 +270,7 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
   addDraftFiles,
   removeDraftFile,
   createSession,
+  undoLastTurnInSession,
   deleteSession,
   updateSessionTitle,
   updateSessionExternalSessionId,
@@ -276,6 +278,7 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
   updateLastMessage,
   updateMessageById,
   persistContextCompaction,
+  forkSessionFromMessage,
   providers,
   activeProviderId,
   activeModelId,
@@ -319,6 +322,11 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
 
   const [showHistory, setShowHistory] = useState(false);
   const [isSending, setIsSending] = useState(false);
+  // Undo-last-turn is still
+  // running. Unlike the send flow this is not reflected in `isSending`, so it
+  // is tracked separately to block sends until the branch settles: a turn
+  // submitted meanwhile would run against the (soon hidden) source session.
+  const [isUndoingLastTurn, setIsUndoingLastTurn] = useState(false);
   const [runtimeAgentModelPresets, setRuntimeAgentModelPresets] = useState<Record<string, { cacheKey: string; models: AgentModelPreset[] }>>({});
   const [runtimeModelWarnings, setRuntimeModelWarnings] = useState<Record<string, { cacheKey: string; message: string }>>({});
   // Tracks SDK runtime model catalogs currently loading (per agent scope):
@@ -821,6 +829,78 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
     && Boolean(effectiveActiveProvider)
     && Boolean(effectiveActiveModelId.trim());
 
+  // Undo last turn: offered only at a safe boundary (never inside a compacted
+  // prefix, never between an assistant tool call and its result).
+  const canUndoLastTurn = useMemo(() => Boolean(
+    activeSession
+    && !isStreaming
+    && resolveUndoLastTurnBoundary(
+      activeSession.messages,
+      activeSession.contextCompaction?.compactedMessageCount ?? 0,
+    ) != null,
+  ), [activeSession, isStreaming]);
+
+  const undoInFlightRef = useRef(false);
+  const handleUndoLastTurn = useCallback(async () => {
+    const sessionId = activeSessionRef.current?.id;
+    if (!sessionId || !undoLastTurnInSession) return;
+    if (isStreaming || isAIChatSessionStreaming(sessionId)) return;
+    // Serialize: while a branch is still being created, `canUndoLastTurn` stays stale, so a quick second
+    // click must not start a parallel undo of the same session — that would
+    // publish duplicate branches and restore the same prompt twice.
+    if (undoInFlightRef.current) return;
+    undoInFlightRef.current = true;
+    setIsUndoingLastTurn(true);
+    try {
+      const result = await undoLastTurnInSession(sessionId);
+      if (!result) return;
+
+      ensureScopeDraft(currentAgentId);
+      // Text typed since the last flush lives only in the live composer buffer
+      // (pendingComposerTextRef/currentDraftRef), not in the persisted draft;
+      // merge from the live buffer so it is not lost, then drop the pending
+      // buffer so the later flushDraftText() cannot overwrite the merged text.
+      const liveDraft = currentDraftRef.current;
+      updateScopeDraft(currentAgentId, (draft) => {
+        const liveText = liveDraft?.text ?? draft.text;
+        const liveSkillSlugs = liveDraft?.selectedUserSkillSlugs ?? draft.selectedUserSkillSlugs;
+        return {
+          ...draft,
+          // Keep anything the user is still typing; the undone prompt goes first.
+          text: liveText.trim()
+            ? `${result.restored.text}\n\n${liveText}`
+            : result.restored.text,
+          attachments: [
+            ...result.restored.attachments,
+            ...(liveDraft?.attachments ?? draft.attachments),
+          ],
+          // The undone turn was selected with these pills; keep any pills the
+          // user picked since the send on top of them.
+          selectedUserSkillSlugs: [
+            ...result.restored.selectedUserSkillSlugs,
+            ...liveSkillSlugs.filter((slug) => !result.restored.selectedUserSkillSlugs.includes(slug)),
+          ],
+        };
+      });
+      discardPendingComposerText();
+      showScopeSessionView(result.sessionId);
+      // Tool side effects live outside the conversation and cannot be rolled back.
+      toast.info(t('ai.chat.undoLastTurnNotice'));
+    } finally {
+      undoInFlightRef.current = false;
+      setIsUndoingLastTurn(false);
+    }
+  }, [
+    discardPendingComposerText,
+    ensureScopeDraft,
+    isStreaming,
+    showScopeSessionView,
+    t,
+    undoLastTurnInSession,
+    updateScopeDraft,
+    currentAgentId,
+  ]);
+
   const providersRef = useRef(providers);
   providersRef.current = providers;
 
@@ -1177,8 +1257,8 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
 
   const inputAgentId = activeSession?.agentId ?? currentDraft?.agentId ?? currentAgentId;
   const canSendCurrentAgent = useMemo(
-    () => !isSending && canSendWithAgent(inputAgentId, externalAgents),
-    [inputAgentId, externalAgents, isSending],
+    () => !isSending && !isUndoingLastTurn && canSendWithAgent(inputAgentId, externalAgents),
+    [inputAgentId, externalAgents, isSending, isUndoingLastTurn],
   );
 
   const handleAgentModelSelect = useCallback((modelId: string) => {
@@ -1314,6 +1394,10 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
     }));
     const hasInlineTextAttachments = attachments.some(isInlineTextAttachment);
     if ((!trimmed && !hasInlineTextAttachments) || isStreaming) return;
+    // While undo-last-turn is creating the branch, the target is still the source; a
+    // turn submitted now would run in the soon-hidden source session, so
+    // block it until the branch settles.
+    if (isUndoingLastTurn) return;
     // Note-only sends (empty text + a mentioned note) still need a usable
     // session title: fall back to the first mentioned note's title so these
     // conversations don't all show up as "Untitled" in history.
@@ -1438,6 +1522,7 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
         addMessageToSession(sessionId, {
           id: generateId(), role: 'user', content: trimmed,
           ...(attachments.length > 0 ? { attachments } : {}),
+          ...(selectedSkillSlugs.length > 0 ? { selectedUserSkillSlugs: selectedSkillSlugs } : {}),
           timestamp: Date.now(),
         });
         addMessageToSession(sessionId, { id: generateId(), role: 'assistant', content: t('ai.chat.noProvider'), timestamp: Date.now() });
@@ -1452,6 +1537,7 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
         addMessageToSession(sessionId, {
           id: generateId(), role: 'user', content: trimmed,
           ...(attachments.length > 0 ? { attachments } : {}),
+          ...(selectedSkillSlugs.length > 0 ? { selectedUserSkillSlugs: selectedSkillSlugs } : {}),
           timestamp: Date.now(),
         });
         addMessageToSession(sessionId, { id: generateId(), role: 'assistant', content: t('ai.chat.noProviderModel'), timestamp: Date.now() });
@@ -1465,6 +1551,8 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
       addMessageToSession(sessionId, {
         id: generateId(), role: 'user', content: trimmed,
         ...(attachments.length > 0 ? { attachments } : {}),
+        // Kept on the user message so undo last turn can restore the pills.
+        ...(selectedSkillSlugs.length > 0 ? { selectedUserSkillSlugs: selectedSkillSlugs } : {}),
         timestamp: Date.now(),
       });
       clearScopeDraft({ keepPendingText: keepPendingAfterSend() });
@@ -1546,7 +1634,7 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
     }
   }, [
     validateNoteMentions, loadCodexConfigModel,
-    isStreaming, activeProvider, effectiveActiveProvider, effectiveActiveModelId, selectedCattyThinking, scopeKey, currentAgentId,
+    isStreaming, isUndoingLastTurn, activeProvider, effectiveActiveProvider, effectiveActiveModelId, selectedCattyThinking, scopeKey, currentAgentId,
     activeModelId, externalAgents,
     createSession, addMessageToSession, updateMessageById, updateLastMessage,
     setStreamingForScope,
@@ -1767,6 +1855,36 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
     [setActiveSessionId, showScopeSessionView],
   );
 
+  // "Fork from here": copy the viewed conversation up to a completed assistant
+  // response into a new session, switch to it, and confirm via toast. The
+  // original stays in history. Boundary validation is re-run by the state
+  // hook; a null result means the fork was refused (already hidden in the UI).
+  // This panel's scope is passed so the branch is created in the scope viewing
+  // it, even when the source session's own scope went stale (e.g. a terminal
+  // chat resumed after reconnecting under a new terminal id).
+  const handleForkFromMessage = useCallback(async (messageId: string) => {
+    const sourceSessionId = activeSessionRef.current?.id ?? activeSessionId;
+    if (!sourceSessionId) return;
+    // Reject a double-click while the new session is being selected so one
+    // interaction cannot create two forks.
+    if (!tryBeginSendForKey(`fork:${sourceSessionId}`)) return;
+    try {
+      const fork = await forkSessionFromMessage?.(sourceSessionId, messageId, {
+        type: scopeType,
+        targetId: scopeTargetId,
+      });
+      if (!fork) return;
+      applyHistorySessionSelection(fork.id, {
+        showSessionView: showScopeSessionView,
+        setActiveSessionId,
+        closeHistory: () => setShowHistory(false),
+      });
+      toast.success(t('ai.chat.forkCreated'));
+    } finally {
+      endSendForKey(`fork:${sourceSessionId}`);
+    }
+  }, [activeSessionId, forkSessionFromMessage, scopeTargetId, scopeType, setActiveSessionId, showScopeSessionView, t]);
+
   const handleDeleteSession = useCallback(
     async (e: React.MouseEvent, sessionId: string) => {
       e.stopPropagation();
@@ -1834,7 +1952,7 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
       >
       <AIChatPanelContent
         parked={!isVisible}
-        sending={isSending}
+        sending={isSending || isUndoingLastTurn}
         t={t}
         currentAgentId={currentAgentId}
         externalAgents={externalAgents}
@@ -1853,6 +1971,7 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
         activeSessionId={activeSessionId}
         handleSelectSession={handleSelectSession}
         handleDeleteSession={handleDeleteSession}
+        onForkFromMessage={handleForkFromMessage}
         messages={messages}
         isStreaming={isStreaming}
         activeCompaction={
@@ -1864,6 +1983,8 @@ const AIChatSidePanelActive: React.FC<AIChatSidePanelProps> = ({
         setInputValue={setInputValue}
         handleSend={handleSend}
         handleCompact={handleCompact}
+        canUndoLastTurn={canUndoLastTurn}
+        handleUndoLastTurn={undoLastTurnInSession ? handleUndoLastTurn : undefined}
         handleSteer={handleSteer}
         handleStop={handleStop}
         canSteer={canSteerCurrentTurn}
@@ -1941,6 +2062,7 @@ const AI_CHAT_SIDE_PANEL_AI_STATE_KEYS = [
   'updateLastMessage',
   'updateMessageById',
   'persistContextCompaction',
+  'forkSessionFromMessage',
   'providers',
   'activeProviderId',
   'activeModelId',

components/AIChatSidePanel.types.ts

@@ -37,6 +37,10 @@ export interface AIChatSidePanelProps {
   addDraftFiles: (scopeKey: string, fallbackAgentId: string, inputFiles: File[]) => Promise<void>;
   removeDraftFile: (scopeKey: string, fallbackAgentId: string, fileId: string) => void;
   createSession: (scope: AISessionScope, agentId?: string) => AISession;
+  /** Non-destructively branch before the last user turn; returns the branch id + restored composer content. */
+  undoLastTurnInSession?: (
+    sessionId: string,
+  ) => Promise<{ sessionId: string; restored: { text: string; attachments: import('../infrastructure/ai/types').UploadedFile[]; selectedUserSkillSlugs: string[] } } | null>;
   deleteSession: (sessionId: string, scopeKey?: string) => void;
   updateSessionTitle: (sessionId: string, title: string) => void;
   updateSessionExternalSessionId: (sessionId: string, externalSessionId: string | undefined) => void;
@@ -54,6 +58,11 @@ export interface AIChatSidePanelProps {
     sessionId: string,
     compaction: import('../infrastructure/ai/types').AISessionContextCompaction,
   ) => void;
+  forkSessionFromMessage?: (
+    sessionId: string,
+    messageId: string,
+    viewingScope?: Pick<AISessionScope, 'type' | 'targetId'>,
+  ) => Promise<AISession | null>;
   // Provider config
   providers: ProviderConfig[];
   activeProviderId: string;

components/GroupDetailsPanel.tsx

@@ -25,6 +25,7 @@ import {
   formatProxyConfigType,
   updateProxyConfigField,
 } from "../domain/proxyProfiles";
+import { canServeAsSshJumpHost } from "../domain/terminalProtocol";
 import {
   EnvVar,
   GroupConfig,
@@ -333,7 +334,12 @@ const GroupDetailsPanel: React.FC<GroupDetailsPanelPropsWithResize> = ({
 
   const availableHostsForChain = useMemo(() => {
     const chainedIds = new Set(form.hostChain?.hostIds || []);
-    return allHosts.filter((h) => !chainedIds.has(h.id));
+    // 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) =>
+      !chainedIds.has(h.id)
+      && canServeAsSshJumpHost(h),
+    );
   }, [allHosts, form.hostChain?.hostIds]);
 
   const addHostToChain = (hostId: string) => {

components/HostDetailsPanel.tsx

@@ -23,6 +23,7 @@ import {
   updateProxyConfigField,
 } from "../domain/proxyProfiles";
 import { hasRequiredHostAuthCredential, resolveHostAuth, resolveHostAuthMethodForPersistence } from "../domain/sshAuth";
+import { canServeAsSshJumpHost } from "../domain/terminalProtocol";
 import { customThemeStore } from "../application/state/customThemeStore";
 import {
   hasHostFontSizeOverride,
@@ -749,7 +750,13 @@ const HostDetailsPanel: React.FC<HostDetailsPanelPropsWithResize> = ({
 
   const availableHostsForChain = useMemo(() => {
     const chainedIds = new Set(form.hostChain?.hostIds || []);
-    return allHosts.filter((h) => h.id !== form.id && !chainedIds.has(h.id));
+    // 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) =>
+      h.id !== form.id
+      && !chainedIds.has(h.id)
+      && canServeAsSshJumpHost(h),
+    );
   }, [allHosts, form.id, form.hostChain?.hostIds]);
 
   const chainedHosts = useMemo(() => {

components/HostTreeView.tsx

@@ -16,6 +16,7 @@ import {
   type HostClickBehavior,
 } from '../domain/hostClickBehavior';
 import { sortByVaultOrder } from '../domain/vaultOrder';
+import { getVaultHostRowSubtitle } from '../domain/localShellHost';
 import { STORAGE_KEY_VAULT_HOSTS_TREE_EXPANDED } from '../infrastructure/config/storageKeys';
 import { GroupConfig, GroupNode, Host } from '../types';
 import { Collapsible, CollapsibleContent, CollapsibleTrigger } from './ui/collapsible';
@@ -726,6 +727,7 @@ const HostTreeItem: React.FC<HostTreeItemProps> = ({
   initialTreeItemKey,
   onActiveTreeItemChange,
 }) => {
+  const { t } = useI18n();
   const safeHost = sanitizeHost(host);
   const tags = host.tags || [];
   const displayDetails = useMemo(
@@ -843,7 +845,9 @@ const HostTreeItem: React.FC<HostTreeItemProps> = ({
                 <HostNotesIndicator notes={host.notes} />
               </div>
               <div className="truncate text-[11px] leading-4 text-muted-foreground">
-                {displayUsername}@{host.hostname}:{displayPort}
+                {displayProtocol === 'local'
+                  ? getVaultHostRowSubtitle(safeHost, { localFallback: t('localShell.subtitle') })
+                  : `${displayUsername}@${host.hostname}:${displayPort}`}
               </div>
             </div>
           )}

components/LocalShellHostDetailsPanel.test.tsx

@@ -0,0 +1,101 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import React from "react";
+import { renderToStaticMarkup } from "react-dom/server";
+import { readFileSync } from "node:fs";
+
+import { LocalShellHostDetailsPanel } from "./LocalShellHostDetailsPanel.tsx";
+import type { Host } from "../types.ts";
+
+const panelSource = readFileSync(
+  new URL("./LocalShellHostDetailsPanel.tsx", import.meta.url),
+  "utf8",
+);
+
+const existingLocalHost = {
+  id: "local-existing",
+  label: "Project A CMD",
+  hostname: "localhost",
+  username: "",
+  tags: ["local"],
+  group: "Projects/A",
+  protocol: "local",
+  os: "linux",
+  createdAt: 0,
+  localShell: "powershell",
+  localShellName: "Windows PowerShell",
+  localShellIcon: "powershell",
+} as unknown as Host;
+
+const noop = () => {};
+
+test("renderToStaticMarkup: create mode shows title, default-shell option and Save & Connect", () => {
+  const markup = renderToStaticMarkup(
+    <LocalShellHostDetailsPanel
+      defaultGroup="Projects/A"
+      groups={["Projects/A", "Infra"]}
+      onSave={noop}
+      onSaveAndConnect={noop}
+      onCancel={noop}
+      layout="inline"
+    />,
+  );
+
+  assert.match(markup, /localShell\.panel\.title/);
+  assert.match(markup, /localShell\.field\.shellDefault/);
+  assert.match(markup, /localShell\.saveAndConnect/);
+  assert.match(markup, /localShell\.saveAndConnect|common\.save/);
+});
+
+test("renderToStaticMarkup: edit mode hides Save & Connect and shows existing shell", () => {
+  const markup = renderToStaticMarkup(
+    <LocalShellHostDetailsPanel
+      initialData={existingLocalHost}
+      groups={["Projects/A"]}
+      onSave={noop}
+      onCancel={noop}
+      layout="inline"
+    />,
+  );
+
+  assert.match(markup, /localShell\.panel\.title\.edit/);
+  assert.doesNotMatch(markup, /localShell\.saveAndConnect/);
+  // Existing label is carried into the form
+  assert.match(markup, /Project A CMD/);
+  assert.match(markup, /local-shell-start-dir/);
+});
+
+test("buildHost preserves the saved OS on edits and detects it only for new entries", () => {
+  // Editing must retain initialData.os: entries imported/synced on one
+  // platform must not be re-classified as the editor machine's OS on save.
+  assert.match(
+    panelSource,
+    /os:\s*initialData\?\.os \?\? detectLocalOs\(navigator\.userAgent \|\| navigator\.platform\)/,
+  );
+});
+
+test("unchanged shell selection keeps stored metadata over discovery", () => {
+  // A host with custom localShellArgs for a shell id that discovery also
+  // matches must keep its stored args/name/icon when an unrelated edit
+  // (label, tag, group) is saved; discovered metadata applies only after
+  // the user changes the shell selection.
+  const unchanged = panelSource.match(
+    /const shellMeta =\s*\n[\s\S]*?shell === initialData\?\.localShell\s*\n\s*\?\s*\{[\s\S]*?\}\s*\n\s*: matchedShell;/,
+  );
+  assert.ok(unchanged, "shellMeta must branch on an unchanged shell selection");
+  // Inside the unchanged branch, stored metadata wins per field and
+  // matchedShell is only a fallback (never the primary source).
+  assert.match(
+    unchanged[0],
+    /args:\s*initialData\?\.localShellArgs \?\? matchedShell\?\.args/,
+  );
+  assert.match(
+    unchanged[0],
+    /name:\s*initialData\?\.localShellName \?\? matchedShell\?\.name/,
+  );
+  assert.match(
+    unchanged[0],
+    /icon:\s*initialData\?\.localShellIcon \?\? matchedShell\?\.icon/,
+  );
+  assert.doesNotMatch(unchanged[0], /matchedShell \?\?/);
+});

components/LocalShellHostDetailsPanel.tsx

@@ -0,0 +1,255 @@
+/**
+ * Local Shell Host Details Panel
+ * A dedicated editor for local shell / CMD vault hosts (protocol 'local'),
+ * distinct from the SSH HostDetailsPanel. Lets users save named local shells
+ * into vault groups next to their SSH hosts (issue #3615).
+ */
+import { Save, TerminalSquare, X } from 'lucide-react';
+import React, { useMemo, useState } from 'react';
+import { useI18n } from '../application/i18n/I18nProvider';
+import { useDiscoveredShells } from '../lib/useDiscoveredShells';
+import { detectLocalOs } from '../lib/localShell';
+import type { Host } from '../domain/models';
+import { createLocalShellHost } from '../domain/localShellHost';
+
+import { Button } from './ui/button';
+import { Combobox, ComboboxOption } from './ui/combobox';
+import { Input } from './ui/input';
+import { Label } from './ui/label';
+import {
+  AsidePanel,
+  AsidePanelContent,
+  AsidePanelFooter,
+  type AsidePanelLayout,
+  type AsidePanelResizeProps,
+} from './ui/aside-panel';
+import { cn } from '../lib/utils';
+
+interface LocalShellHostDetailsPanelProps {
+  /** Existing host when editing; null/undefined when creating a new entry. */
+  initialData?: Host | null;
+  defaultGroup?: string;
+  groups?: string[];
+  onSave: (host: Host) => void;
+  /** Saves the host and immediately opens a terminal for it. */
+  onSaveAndConnect?: (host: Host) => void;
+  onCancel: () => void;
+  layout?: AsidePanelLayout;
+  className?: string;
+}
+
+type LocalShellHostDetailsPanelPropsWithResize =
+  LocalShellHostDetailsPanelProps & AsidePanelResizeProps;
+
+export const LocalShellHostDetailsPanel: React.FC<LocalShellHostDetailsPanelPropsWithResize> = ({
+  initialData,
+  defaultGroup,
+  groups = [],
+  onSave,
+  onSaveAndConnect,
+  onCancel,
+  layout = 'overlay',
+  className,
+  resizable,
+  persistWidthStorageKey,
+  resizeAriaLabel,
+}) => {
+  const { t } = useI18n();
+  const discoveredShells = useDiscoveredShells();
+
+  const [label, setLabel] = useState(initialData?.label ?? '');
+  const [shell, setShell] = useState(initialData?.localShell ?? '');
+  const [startDir, setStartDir] = useState(initialData?.localStartDir ?? '');
+  // On creation, initialize from defaultGroup so the field reflects what a
+  // plain save would persist; clearing it then intentionally saves at the
+  // vault root. Edits keep the host's own group (possibly empty).
+  const [group, setGroup] = useState(
+    initialData ? initialData.group ?? '' : defaultGroup ?? '',
+  );
+
+  const matchedShell = useMemo(
+    () => discoveredShells.find((candidate) => candidate.id === shell),
+    [discoveredShells, shell],
+  );
+
+  // While the shell selection is unchanged from the saved host, prefer the
+  // host's stored metadata: an imported/synced host may carry custom startup
+  // arguments for a shell id that also exists in discovery, and saving an
+  // unrelated edit (label, tag, group) must not overwrite them with the
+  // current discovery result. Discovered metadata applies only after the user
+  // changes the selection — or per-field when the host stores none.
+  const shellMeta =
+    shell && shell === initialData?.localShell
+      ? {
+          args: initialData?.localShellArgs ?? matchedShell?.args,
+          name: initialData?.localShellName ?? matchedShell?.name,
+          icon: initialData?.localShellIcon ?? matchedShell?.icon,
+        }
+      : matchedShell;
+
+  const shellOptions: ComboboxOption[] = useMemo(() => {
+    const options: ComboboxOption[] = [
+      { value: '', label: t('localShell.field.shellDefault') },
+    ];
+    for (const candidate of discoveredShells) {
+      options.push({
+        value: candidate.id,
+        label: candidate.name,
+        sublabel: candidate.command,
+      });
+    }
+    return options;
+  }, [discoveredShells, t]);
+
+  const groupOptions: ComboboxOption[] = useMemo(() => {
+    const allGroups = new Set(groups);
+    if (group && !allGroups.has(group)) {
+      allGroups.add(group);
+    }
+    return Array.from(allGroups).map((g) => ({
+      value: g,
+      label: g,
+    }));
+  }, [groups, group]);
+
+  const buildHost = (): Host => {
+    const host = createLocalShellHost({
+      id: initialData?.id,
+      // Keep the entry's saved OS on edits: importing/syncing on one platform
+      // then editing elsewhere must not silently re-classify the host (shell
+      // defaults, CSV round trips, dedup) as the editor machine's OS.
+      os: initialData?.os ?? detectLocalOs(navigator.userAgent || navigator.platform),
+      label,
+      shell,
+      shellArgs: shellMeta?.args,
+      shellName: shellMeta?.name,
+      shellIcon: shellMeta?.icon,
+      startDir,
+      // Save the controlled value directly: '' means the user explicitly
+      // cleared the group, which persists at the vault root.
+      group: group,
+      tags: initialData?.tags,
+      notes: initialData?.notes,
+    });
+    // On edits, merge over the existing host so fields this form does not
+    // expose (pinned, lastConnectedAt, order, ...) and the original
+    // creation timestamp survive a save.
+    return initialData
+      ? { ...initialData, ...host, createdAt: initialData.createdAt ?? host.createdAt }
+      : host;
+  };
+
+  const handleSave = () => onSave(buildHost());
+  const handleSaveAndConnect = () => {
+    if (!onSaveAndConnect) return;
+    onSaveAndConnect(buildHost());
+  };
+
+  return (
+    <AsidePanel
+      open={true}
+      onClose={onCancel}
+      title={initialData ? t('localShell.panel.title.edit') : t('localShell.panel.title')}
+      subtitle={initialData?.label}
+      className={cn('z-40', className)}
+      layout={layout}
+      dataSection="local-shell-host-details-panel"
+      resizable={resizable}
+      persistWidthStorageKey={persistWidthStorageKey}
+      resizeAriaLabel={resizeAriaLabel}
+    >
+      <AsidePanelContent>
+        {/* Label */}
+        <div className="space-y-2">
+          <Label htmlFor="local-shell-label">{t('localShell.field.label')}</Label>
+          <Input
+            id="local-shell-label"
+            value={label}
+            onChange={(e) => setLabel(e.target.value)}
+            placeholder={t('localShell.field.labelPlaceholder')}
+          />
+        </div>
+
+        {/* Shell */}
+        <div className="space-y-2">
+          <Label>{t('localShell.field.shell')}</Label>
+          <Combobox
+            options={shellOptions}
+            value={shell}
+            onValueChange={setShell}
+            placeholder={t('localShell.field.shellDefault')}
+            emptyText={t('localShell.field.shellEmpty')}
+            allowCreate
+            createText={t('common.use')}
+            icon={<TerminalSquare size={14} className="text-muted-foreground" />}
+          />
+          <p className="text-xs text-muted-foreground">
+            {matchedShell
+              ? t('localShell.field.shellResolved', { command: matchedShell.command })
+              : t('localShell.field.shellDefaultDesc')}
+          </p>
+        </div>
+
+        {/* Group */}
+        <div className="space-y-2">
+          <Label>{t('hostDetails.group')}</Label>
+          <Combobox
+            options={groupOptions}
+            value={group}
+            onValueChange={setGroup}
+            placeholder={t('hostDetails.selectGroup')}
+            allowCreate
+            createText={t('hostDetails.createGroup')}
+          />
+        </div>
+
+        {/* Start directory */}
+        <div className="space-y-2">
+          <Label htmlFor="local-shell-start-dir">{t('localShell.field.startDir')}</Label>
+          <div className="relative">
+            <Input
+              id="local-shell-start-dir"
+              value={startDir}
+              onChange={(e) => setStartDir(e.target.value)}
+              placeholder={t('localShell.field.startDirPlaceholder')}
+              className="pr-8"
+            />
+            {startDir && (
+              <button
+                type="button"
+                onClick={() => setStartDir('')}
+                aria-label={t('common.reset')}
+                className="absolute right-2 top-1/2 -translate-y-1/2 p-1 text-muted-foreground hover:text-foreground transition-colors"
+              >
+                <X size={14} />
+              </button>
+            )}
+          </div>
+        </div>
+      </AsidePanelContent>
+
+      <AsidePanelFooter>
+        <div className="flex gap-2">
+          <Button variant="ghost" onClick={onCancel} className="flex-1">
+            {t('common.cancel')}
+          </Button>
+          {onSaveAndConnect && !initialData && (
+            <Button
+              onClick={handleSaveAndConnect}
+              className="flex-1"
+            >
+              <TerminalSquare size={14} className="mr-2" />
+              {t('localShell.saveAndConnect')}
+            </Button>
+          )}
+          <Button onClick={handleSave} className="flex-1">
+            <Save size={14} className="mr-2" />
+            {t('common.save')}
+          </Button>
+        </div>
+      </AsidePanelFooter>
+    </AsidePanel>
+  );
+};
+
+export default LocalShellHostDetailsPanel;

components/SelectHostPanel.tsx

@@ -30,6 +30,8 @@ interface SelectHostPanelProps {
   resizable?: boolean;
   persistWidthStorageKey?: string;
   resizeAriaLabel?: string;
+  /** Allow saved local-shell (CMD/PowerShell/...) hosts as targets, e.g. snippet/script runners. */
+  allowLocalHosts?: boolean;
 }
 
 const SelectHostPanel: React.FC<SelectHostPanelProps> = ({
@@ -56,6 +58,7 @@ const SelectHostPanel: React.FC<SelectHostPanelProps> = ({
   resizable = false,
   persistWidthStorageKey,
   resizeAriaLabel,
+  allowLocalHosts = false,
 }) => {
   const { t } = useI18n();
   const [newHostPanelOpen, setNewHostPanelOpen] = useState(false);
@@ -103,6 +106,7 @@ const SelectHostPanel: React.FC<SelectHostPanelProps> = ({
         onSaveHost={onSaveHost}
         onCreateGroup={onCreateGroup}
         onNewHostPanelOpenChange={setNewHostPanelOpen}
+        allowLocalHosts={allowLocalHosts}
         className="flex-1 min-h-0"
       />
     </AsidePanel>

components/SelectHostPanelContent.tsx

@@ -58,6 +58,8 @@ export interface SelectHostPanelContentProps {
   onSaveHost?: (host: Host) => void;
   onCreateGroup?: (groupPath: string) => void;
   onNewHostPanelOpenChange?: (open: boolean) => void;
+  /** Allow saved local-shell (CMD/PowerShell/...) hosts as targets, e.g. snippet/script runners. */
+  allowLocalHosts?: boolean;
   className?: string;
 }
 
@@ -85,6 +87,7 @@ export const SelectHostPanelContent: React.FC<SelectHostPanelContentProps> = ({
   onSaveHost,
   onCreateGroup,
   onNewHostPanelOpenChange,
+  allowLocalHosts = false,
   className,
 }) => {
   const { t } = useI18n();
@@ -106,9 +109,14 @@ export const SelectHostPanelContent: React.FC<SelectHostPanelContentProps> = ({
     onNewHostPanelOpenChange?.(showNewHostPanel);
   }, [onNewHostPanelOpenChange, showNewHostPanel]);
 
+  // This panel picks hosts for SSH-backed capabilities (tunnels, keychain
+  // key export targets); serial hosts have no SSH session to target and, by
+  // default, neither do local-shell hosts. Snippet/script target pickers pass
+  // `allowLocalHosts` because their domain treats every non-serial host
+  // (including saved CMD/PowerShell shells) as a runnable target.
   const selectableHosts = useMemo(
-    () => hosts.filter((host) => host.protocol !== 'serial'),
-    [hosts],
+    () => hosts.filter((host) => host.protocol !== 'serial' && (allowLocalHosts || host.protocol !== 'local')),
+    [hosts, allowLocalHosts],
   );
   const selectedHostIdSet = useMemo(
     () => new Set(selectedHostIds),

components/SnippetsRightPanel.tsx

@@ -132,6 +132,7 @@ export const SnippetsRightPanel: React.FC<SnippetsRightPanelProps> = ({
           customGroups={customGroups}
           selectedHostIds={targetSelection}
           multiSelect={true}
+          allowLocalHosts={true}
           onSelect={handleTargetSelect}
           onSelectionChange={handleTargetSelectionChange}
           onBack={handleTargetPickerBack}

components/TerminalLayer.tsx

@@ -50,6 +50,7 @@ import {
   resolveTerminalChainHosts,
   resolveTerminalSessionHost,
 } from '../domain/terminalHostResolution';
+import { useDefaultLocalShellContext } from '../lib/useDiscoveredShells';
 import { Tooltip, TooltipContent, TooltipTrigger } from './ui/tooltip';
 import { toast } from './ui/toast';
 import { useI18n } from '../application/i18n/I18nProvider';
@@ -182,7 +183,7 @@ function buildScriptSessionMeta(
     connected: session.status === 'connected',
     name: session.customName || session.hostLabel || host?.label,
     hostname: host?.hostname ?? session.hostname,
-    username: host?.username ?? session.username,
+    username: session.protocol === 'local' ? session.username : host?.username ?? session.username,
   };
 }
 
@@ -669,7 +670,9 @@ const TerminalLayerInner: React.FC<TerminalLayerProps> = ({
   const handleSessionExit = useCallback((sessionId: string, evt: TerminalSessionExitEvent) => {
     const intent = resolveTerminalSessionExitIntent(
       evt,
-      terminalSettings?.autoCloseOnExit ?? true,
+      // No terminal settings loaded yet -> do not close the tab; auto-close is
+      // opt-in via Settings -> Terminal -> Behavior (DEFAULT_TERMINAL_SETTINGS).
+      terminalSettings?.autoCloseOnExit ?? false,
     );
     if (intent.kind === "closeSession") {
       handleCloseSession(sessionId);
@@ -1193,14 +1196,16 @@ const TerminalLayerInner: React.FC<TerminalLayerProps> = ({
     () => new Set(proxyProfiles.map((profile) => profile.id)),
     [proxyProfiles],
   );
+  const defaultLocalShell = useDefaultLocalShellContext(terminalSettings);
   const effectiveHosts = useMemo(
     () => hosts.map((host) => resolveEffectiveTerminalHost({
       host,
       groupConfigs,
       proxyProfiles,
       validProxyProfileIds: proxyProfileIdSet,
+      defaultLocalShell,
     })),
-    [groupConfigs, hosts, proxyProfileIdSet, proxyProfiles],
+    [groupConfigs, hosts, proxyProfileIdSet, proxyProfiles, defaultLocalShell],
   );
 
   // Pre-compute fallback hosts to avoid creating new objects on every render
@@ -1213,11 +1218,12 @@ const TerminalLayerInner: React.FC<TerminalLayerProps> = ({
         groupConfigs,
         proxyProfiles,
         localOs: detectLocalOs(navigator.userAgent || navigator.platform),
+        defaultLocalShell,
       });
       map.set(session.id, applySessionFontSizeToHost(hostForSession, session));
     }
     return map;
-  }, [sessions, hosts, groupConfigs, proxyProfiles]);
+  }, [sessions, hosts, groupConfigs, proxyProfiles, defaultLocalShell]);
   const resolvedSessionHostIds = useMemo(() => {
     const ids = new Set<string>();
     for (const session of sessions) {

components/TerminalPopupPage.test.ts

@@ -5,6 +5,7 @@ import { readFileSync } from 'node:fs';
 import type { Host, TerminalSession } from '../types';
 import type { TerminalPopupPayload } from '../domain/systemManager/types';
 import { resolveTerminalPopupHost, resolveTerminalPopupReuseId } from './TerminalPopupPage';
+import { resolveShellSetting } from '../lib/useDiscoveredShells';
 
 const source = readFileSync(new URL('./TerminalPopupPage.tsx', import.meta.url), 'utf8');
 const terminalSource = readFileSync(new URL('./Terminal.tsx', import.meta.url), 'utf8');
@@ -53,6 +54,36 @@ test('resolveTerminalPopupHost honors source session transport over saved Mosh h
   assert.equal(host.etEnabled, false);
 });
 
+test('resolveTerminalPopupHost resolves the settings shell for saved local hosts with a system default shell', () => {
+  const localHost = vaultHost({
+    protocol: 'local',
+    hostname: 'localhost',
+    username: '',
+    port: undefined,
+    localShell: undefined,
+  });
+  const defaultLocalShell = {
+    discoveredShells: [],
+    resolveShellSetting,
+    terminalSettings: { localShell: 'fish', localShellArgs: [] },
+  };
+
+  const withContext = resolveTerminalPopupHost(
+    popupPayload(sourceSession({ protocol: 'local', port: undefined })),
+    [localHost],
+    { defaultLocalShell },
+  );
+  assert.equal(withContext.localShell, 'fish');
+
+  // Without the context (e.g. callers that cannot resolve it) the vault host
+  // keeps its saved (empty) shell — the caller decides how to handle it.
+  const withoutContext = resolveTerminalPopupHost(
+    popupPayload(sourceSession({ protocol: 'local', port: undefined })),
+    [localHost],
+  );
+  assert.equal(withoutContext.localShell, undefined);
+});
+
 test('resolveTerminalPopupHost still falls back to source session details when the host is missing', () => {
   const host = resolveTerminalPopupHost(popupPayload(sourceSession({ hostId: 'missing' })), []);
 
@@ -162,7 +193,7 @@ test('attach popup close preparation has a bounded timeout', () => {
 test('terminal exit auto-close setting reaches tabs, workspaces, and popups', () => {
   assert.match(
     terminalLayerSource,
-    /resolveTerminalSessionExitIntent\(\s+evt,\s+terminalSettings\?\.autoCloseOnExit \?\? true,\s+\)/,
+    /resolveTerminalSessionExitIntent\(\s+evt,[\s\S]*?terminalSettings\?\.autoCloseOnExit \?\? false,\s+\)/,
   );
   assert.match(
     terminalSource,

components/TerminalPopupPage.tsx

@@ -12,12 +12,14 @@ import {
 } from '../application/state/resolveTerminalSessionExitIntent';
 import { upsertKnownHost } from '../domain/knownHosts';
 import { isPluginHostProtocol, sanitizePluginConnection } from '../domain/pluginConnection';
+import type { ResolveDefaultLocalShellContext } from '../domain/localShellHost';
 import { resolveTerminalChainHosts, resolveTerminalSessionHost } from '../domain/terminalHostResolution';
 import type { TerminalPopupPayload } from '../domain/systemManager/types';
 import type { GroupConfig, Host, ProxyProfile, TerminalTheme } from '../domain/models';
 import type { KnownHost } from '../types';
 import { getEffectiveKnownHosts } from '../infrastructure/syncHelpers';
 import { detectLocalOs } from '../lib/localShell';
+import { useDefaultLocalShellContext } from '../lib/useDiscoveredShells';
 import { cn } from '../lib/utils';
 import type { AppLockGateRenderContext } from './AppLockGate';
 import { PluginAuthenticationHost } from './plugins/PluginAuthenticationHost';
@@ -233,6 +235,7 @@ export function resolveTerminalPopupHost(
     groupConfigs?: GroupConfig[];
     proxyProfiles?: ProxyProfile[];
     localOs?: Host['os'];
+    defaultLocalShell?: ResolveDefaultLocalShellContext;
   } = {},
 ): Host {
   const resolvedHost = resolveTerminalSessionHost({
@@ -241,6 +244,7 @@ export function resolveTerminalPopupHost(
     groupConfigs: options.groupConfigs ?? [],
     proxyProfiles: options.proxyProfiles ?? [],
     localOs: options.localOs ?? 'linux',
+    defaultLocalShell: options.defaultLocalShell,
   });
   return applySourceSessionConnectionOverrides(
     resolvedHost,
@@ -366,14 +370,17 @@ function TerminalPopupPageInner({
     });
   }, [attachAuthorization, attachSessionId, handleClose, onPrepareClose]);
 
+  const defaultLocalShell = useDefaultLocalShellContext(settings.terminalSettings);
+
   const host = useMemo(() => {
     if (!config) return null;
     return resolveTerminalPopupHost(config, hosts, {
       groupConfigs,
       proxyProfiles,
       localOs: detectLocalOs(navigator.userAgent || navigator.platform),
+      defaultLocalShell,
     });
-  }, [config, groupConfigs, hosts, proxyProfiles]);
+  }, [config, groupConfigs, hosts, proxyProfiles, defaultLocalShell]);
 
   const chainHosts = useMemo(() => resolveTerminalChainHosts({
     host,

components/VaultView.localShellSave.test.ts

@@ -0,0 +1,111 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import ts from "typescript";
+import { upsertHostById } from "../domain/host";
+import { saveWorkSurfaceHostDraft } from "../application/state/useWorkSurfaceHostEditor";
+import { createLocalShellHost } from "../domain/localShellHost";
+import type { Host } from "../types";
+
+// Execute the actual Vault save callback with its persistence boundary stubbed.
+const source = readFileSync(new URL("./VaultView.tsx", import.meta.url), "utf8");
+const callback = source.match(/const handleSaveLocalShellHost = useCallback\((\(host: Host, connectNow\?: boolean\) => \{[\s\S]*?)\}, \[/)?.[1];
+assert.ok(callback);
+const compiled = ts.transpile(`const save = ${callback}};`, { target: ts.ScriptTarget.ES2022 });
+
+for (const editing of [false, true]) {
+  for (const connectNow of [false, true]) {
+    test(`local shell save: editing=${editing}, connect=${connectNow}`, () => {
+      const opened = createLocalShellHost({ id: "local-1", label: "old", tags: ["old"], notes: "clear me" });
+      const latest = { ...opened, showLineTimestamps: true, lastConnectedAt: 42 };
+      const draft = { ...opened, tags: ["edited"], notes: undefined };
+      let saved: Host[] = [];
+      let connected: Host | undefined;
+      // Mirror useVaultState.updateHosts: hostsRef holds the freshest host
+      // array and accepts an array or functional updater argument.
+      const hostsRef: { current: Host[] } = { current: editing ? [latest] : [] };
+      const save = new Function(
+        "hosts", "editingLocalShellHost", "onUpdateHosts", "onConnect",
+        "setIsLocalShellHostPanelOpen", "setEditingLocalShellHost",
+        "upsertHostById", "saveWorkSurfaceHostDraft",
+        `${compiled} return save;`,
+      )(
+        editing ? [latest] : [], editing ? opened : null,
+        (data: Host[] | ((prev: Host[]) => Host[])) => {
+          const next = typeof data === "function" ? data(hostsRef.current) : data;
+          if (next) hostsRef.current = next;
+          saved = next ?? hostsRef.current;
+        },
+        (host: Host) => { connected = host; },
+        () => {}, () => {}, upsertHostById, saveWorkSurfaceHostDraft,
+      );
+      save(draft, connectNow);
+      assert.equal(saved.length, 1);
+      assert.deepEqual(saved[0], editing ? { ...latest, tags: ["edited"], notes: undefined } : draft);
+      assert.deepEqual(connected, connectNow ? saved[0] : undefined);
+    });
+  }
+}
+
+// Saving must apply the draft against the freshest host array, not the array
+// captured at render time — a concurrent vault write between render and Save
+// would otherwise be replaced wholesale by the stale snapshot.
+test("local shell save: updater merges against the latest host array", () => {
+  const opened = createLocalShellHost({ id: "local-1", label: "old", tags: ["old"] });
+  const draft = { ...opened, tags: ["edited"] };
+  // A concurrent write lands after the render that captured `hosts`.
+  const concurrent = createLocalShellHost({ id: "local-2", label: "later" });
+  const renderedHosts = [opened];
+  const actualHosts = [...renderedHosts, concurrent];
+  // Mirror useVaultState.updateHosts: hostsRef holds the freshest host array
+  // (including the concurrent write) and accepts an array or updater argument.
+  let saved: Host[] = [];
+  const hostsRef: { current: Host[] } = { current: actualHosts };
+  const save = new Function(
+    "hosts", "editingLocalShellHost", "onUpdateHosts", "onConnect",
+    "setIsLocalShellHostPanelOpen", "setEditingLocalShellHost",
+    "upsertHostById", "saveWorkSurfaceHostDraft",
+    `${compiled} return save;`,
+  )(
+    renderedHosts, opened,
+    (data: Host[] | ((prev: Host[]) => Host[])) => {
+      const next = typeof data === "function" ? data(hostsRef.current) : data;
+      if (next) hostsRef.current = next;
+      saved = next ?? hostsRef.current;
+    },
+    () => {}, () => {}, () => {}, upsertHostById, saveWorkSurfaceHostDraft,
+  );
+  save(draft, false);
+  assert.equal(saved.length, 2, "concurrently added host must survive the save");
+  assert.ok(saved.some((host) => host.id === "local-2"));
+  assert.ok(saved.some((host) => host.id === "local-1" && host.tags.includes("edited")));
+});
+
+// Duplicating a local-shell host opens its copy under a newly generated ID
+// that is not in the vault yet; it must be saved as a new entry, not as an
+// edit (which would no-op and silently discard the duplicate).
+test("local shell save: duplicated host with a new id saves as a new entry", () => {
+  const opened = createLocalShellHost({ label: "cmd (copy)" });
+  const draft = { ...opened, notes: "tweaked" };
+  let saved: Host[] = [];
+  let connected: Host | undefined;
+  const save = new Function(
+    "hosts", "editingLocalShellHost", "onUpdateHosts", "onConnect",
+    "setIsLocalShellHostPanelOpen", "setEditingLocalShellHost",
+    "upsertHostById", "saveWorkSurfaceHostDraft",
+    `${compiled} return save;`,
+  )(
+    [], opened,
+    // Mirror useVaultState.updateHosts: accepts an array or a functional
+    // updater applied against the freshest host array (here, the vault is
+    // empty at render time and stays empty in prev too).
+    (data: Host[] | ((prev: Host[]) => Host[])) => { saved = typeof data === "function" ? data(saved) : data; },
+    (host: Host) => { connected = host; },
+    () => {}, () => {}, upsertHostById, saveWorkSurfaceHostDraft,
+  );
+  save(draft, false);
+  assert.equal(saved.length, 1);
+  assert.equal(saved[0].id, draft.id);
+  assert.equal(saved[0].notes, "tweaked");
+  assert.equal(connected, undefined);
+});

components/VaultView.tsx

@@ -73,6 +73,7 @@ import {
   upsertHostById,
 } from "../domain/host";
 import { exportHostsToCsvWithStats } from "../domain/vaultImport";
+import { saveWorkSurfaceHostDraft, type WorkSurfaceHostEditorTarget } from "../application/state/useWorkSurfaceHostEditor";
 import { upsertKnownHost } from "../domain/knownHosts";
 import {
   remapSnippetTargetGroupPaths,
@@ -238,7 +239,9 @@ interface VaultViewProps {
   onDeleteHost: (id: string) => void;
   onConnect: (host: Host) => void;
   onOpenHostFromNote?: (host: Host, source?: { noteId: string }) => void;
-  onUpdateHosts: (hosts: Host[]) => VaultHostPersistenceResult | Promise<VaultHostPersistenceResult>;
+  onUpdateHosts: (
+    hosts: Host[] | ((prev: Host[]) => Host[]),
+  ) => VaultHostPersistenceResult | Promise<VaultHostPersistenceResult>;
   onReadPersistedHosts: () => Promise<Host[]>;
   onUpdateKeys: (keys: SSHKey[]) => void;
   onImportOrReuseKey: (draft: Partial<SSHKey>) => SSHKey;
@@ -458,6 +461,9 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
   const [isHostPanelOpen, setIsHostPanelOpen] = useState(false);
   const [editingHost, setEditingHost] = useState<Host | null>(null);
   const [newHostGroupPath, setNewHostGroupPath] = useState<string | null>(null);
+  // Local shell (CMD) host panel state — a vault host entry with protocol 'local'
+  const [isLocalShellHostPanelOpen, setIsLocalShellHostPanelOpen] = useState(false);
+  const [editingLocalShellHost, setEditingLocalShellHost] = useState<Host | null>(null);
   const [pendingOpenNoteId, setPendingOpenNoteId] = useState<string | null>(
     null,
   );
@@ -473,8 +479,17 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
     setCurrentSection("hosts");
     setSelectedGroupPath(null);
     setNewHostGroupPath(null);
-    setEditingHost(deepLinkHostDraft);
-    setIsHostPanelOpen(true);
+    if (deepLinkHostDraft.protocol === "local") {
+      setEditingHost(null);
+      setIsHostPanelOpen(false);
+      setEditingLocalShellHost(deepLinkHostDraft);
+      setIsLocalShellHostPanelOpen(true);
+    } else {
+      setIsLocalShellHostPanelOpen(false);
+      setEditingLocalShellHost(null);
+      setEditingHost(deepLinkHostDraft);
+      setIsHostPanelOpen(true);
+    }
     onDeepLinkHostDraftHandled?.();
   }, [deepLinkHostDraft, onDeepLinkHostDraftHandled]);
 
@@ -507,17 +522,17 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
   useEffect(() => {
     const currentIds = new Set(hosts.map((h) => h.id));
     // Check against previous IDs before updating the ref
-    if (
-      editingHost &&
-      knownHostIdsRef.current.has(editingHost.id) &&
-      !currentIds.has(editingHost.id)
-    ) {
+    const editingDeleted = (openHost: Host | null) =>
+      Boolean(openHost && knownHostIdsRef.current.has(openHost.id) && !currentIds.has(openHost.id));
+    if (editingDeleted(editingHost) || editingDeleted(editingLocalShellHost)) {
       setIsHostPanelOpen(false);
       setEditingHost(null);
+      setIsLocalShellHostPanelOpen(false);
+      setEditingLocalShellHost(null);
       setNewHostGroupPath(null);
     }
     knownHostIdsRef.current = currentIds;
-  }, [hosts, editingHost]);
+  }, [hosts, editingHost, editingLocalShellHost]);
 
   // Group panel state
   const [isGroupPanelOpen, setIsGroupPanelOpen] = useState(false);
@@ -599,8 +614,12 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
             {},
             { validProxyProfileIds: proxyProfileIdSet },
           );
-      // Only prompt when Telnet is available but isn't the host's default protocol.
-      if (effective.telnetEnabled && effective.protocol !== "telnet") {
+      // Only prompt when Telnet is available but isn't the host's default
+      // protocol, and only for SSH hosts: local-shell and serial hosts must
+      // always launch their own transport, never an inherited group Telnet
+      // flag. Hosts without an explicit protocol are legacy SSH entries.
+      const effectiveProtocol = effective.protocol ?? "ssh";
+      if (effectiveProtocol === "ssh" && effective.telnetEnabled) {
         setProtocolSelectHost(effective);
       } else if (effective.protocol === "telnet") {
         // Telnet-as-default wins over a stray moshEnabled flag.
@@ -654,13 +673,67 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
     setIsGroupPanelOpen(false);
     setEditingGroupPath(null);
     setEditingHost(null);
+    setIsLocalShellHostPanelOpen(false);
+    setEditingLocalShellHost(null);
     setNewHostGroupPath(null);
     setIsHostPanelOpen(true);
   }, []);
 
+  // "Local shell (CMD)" entry under the New Host menu — opens the dedicated
+  // local-shell host editor with the current vault group preselected.
+  const handleNewLocalShellHost = useCallback(() => {
+    setIsGroupPanelOpen(false);
+    setEditingGroupPath(null);
+    setEditingHost(null);
+    setIsHostPanelOpen(false);
+    setEditingLocalShellHost(null);
+    setNewHostGroupPath(null);
+    setIsLocalShellHostPanelOpen(true);
+  }, []);
+
+  const handleCancelLocalShellHost = useCallback(() => {
+    setIsLocalShellHostPanelOpen(false);
+    setEditingLocalShellHost(null);
+  }, []);
+
+  const handleSaveLocalShellHost = useCallback((host: Host, connectNow?: boolean) => {
+    // A duplicated local host carries a freshly generated ID that is not in the
+    // vault yet, so it must be saved as a new entry (edit mode would no-op).
+    // (Note: the mode is derived from the rendered hosts snapshot only, so the
+    // updater below can still merge against the up-to-date vault array.)
+    const editingExistingHost = hosts.some((entry) => entry.id === editingLocalShellHost?.id);
+    const target: WorkSurfaceHostEditorTarget = editingExistingHost && editingLocalShellHost
+      ? { mode: "edit", openedHost: editingLocalShellHost, requestId: 0 }
+      : { mode: "new", defaultGroup: null, requestId: 0 };
+    // Apply the draft against the freshest host array, not the one captured at
+    // render time: another vault write (terminal metadata, sync) may have
+    // updated hostsRef between render and Save, and submitting the captured
+    // array would replace it wholesale.
+    let savedHost: Host | null = null;
+    onUpdateHosts((prevHosts) => {
+      const updatedHosts = saveWorkSurfaceHostDraft(prevHosts, target, host);
+      if (!updatedHosts) return prevHosts;
+      savedHost = updatedHosts.find((entry) => entry.id === host.id) ?? null;
+      return updatedHosts;
+    });
+    setIsLocalShellHostPanelOpen(false);
+    setEditingLocalShellHost(null);
+    if (connectNow && savedHost) onConnect(savedHost);
+  }, [hosts, editingLocalShellHost, onConnect, onUpdateHosts]);
+
   const handleEditHost = useCallback((host: Host) => {
     setIsGroupPanelOpen(false);
     setEditingGroupPath(null);
+    // Local shell hosts route to their dedicated editor (no SSH auth fields).
+    if (host.protocol === "local") {
+      setEditingHost(null);
+      setIsHostPanelOpen(false);
+      setEditingLocalShellHost(host);
+      setIsLocalShellHostPanelOpen(true);
+      return;
+    }
+    setIsLocalShellHostPanelOpen(false);
+    setEditingLocalShellHost(null);
     setEditingHost(host);
     setIsHostPanelOpen(true);
   }, []);
@@ -687,6 +760,15 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
         lastConnectedAt: undefined,
       };
       // Open the edit panel with the duplicated host for modification
+      if (duplicatedHost.protocol === "local") {
+        setEditingHost(null);
+        setIsHostPanelOpen(false);
+        setEditingLocalShellHost(duplicatedHost);
+        setIsLocalShellHostPanelOpen(true);
+        return;
+      }
+      setEditingLocalShellHost(null);
+      setIsLocalShellHostPanelOpen(false);
       setEditingHost(duplicatedHost);
       setIsHostPanelOpen(true);
     },
@@ -1276,6 +1358,7 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
     handleUnmanageGroup,
     managedGroupPaths,
     moveHostToGroup,
+    moveHostsToGroup,
     setDragOverDropTarget,
     setGroupDragOverDropTarget,
   } = useVaultGroupDragHandlers({
@@ -1355,7 +1438,9 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
   const isHostsSectionActive = currentSection === "hosts";
   const hasHostsSidePanel =
     isHostsSectionActive &&
-    ((isGroupPanelOpen && !!editingGroupPath) || isHostPanelOpen);
+    ((isGroupPanelOpen && !!editingGroupPath)
+      || isHostPanelOpen
+      || isLocalShellHostPanelOpen);
   // Every host grid uses the same container-based fixed column count. This keeps
   // pinned/recent cards aligned with the virtualized main grid and prevents a
   // single card from stretching across the full row.
@@ -1469,6 +1554,9 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
           handleHostConnect,
           handleImportFileSelected,
           handleNewHost,
+          handleNewLocalShellHost,
+          handleCancelLocalShellHost,
+          handleSaveLocalShellHost,
           handleProtocolSelect,
           handleQuickConnect,
           handleQuickConnectSaveHost,
@@ -1488,6 +1576,8 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
           isDeleteGroupOpen,
           isGroupPanelOpen,
           isHostPanelOpen,
+          isLocalShellHostPanelOpen,
+          editingLocalShellHost,
           isHostsSectionActive,
           isImportOpen,
           isMultiSelectMode,
@@ -1513,6 +1603,7 @@ const VaultViewInner: React.FC<VaultViewProps> = ({
           managedSources,
           moveGroup,
           moveHostToGroup,
+          moveHostsToGroup,
           Network,
           newFolderName,
           newHostGroupPath,

components/VaultViewLayout.test.ts

@@ -20,8 +20,10 @@ test("vault header collapsed actions cannot retain hidden focus", () => {
   assert.match(vaultViewLayoutSource, /newHostActionsRef\.current\?\.contains\(activeElement\)/);
   assert.match(vaultViewLayoutSource, /sessionActionsRef\.current\?\.contains\(activeElement\)/);
   assert.match(vaultViewLayoutSource, /activeElement\.blur\(\)/);
-  assert.match(vaultViewLayoutSource, /aria-hidden=\{isHostPanelOpen \? true : undefined\}/);
-  assert.match(vaultViewLayoutSource, /inert=\{isHostPanelOpen \? true : undefined\}/);
+  // Both the SSH/new-host panel and the local-shell host panel collapse the
+  // header actions so hidden buttons cannot retain focus.
+  assert.match(vaultViewLayoutSource, /aria-hidden=\{isHostAsideOpen \? true : undefined\}/);
+  assert.match(vaultViewLayoutSource, /inert=\{isHostAsideOpen \? true : undefined\}/);
 });
 
 test("vault sidebar toggle keeps an accessible action label", () => {

components/ai/ChatMessageList.test.tsx

@@ -585,3 +585,20 @@ test("Codex approval render plan preserves every approval for the same item", ()
     ["approval-3"],
   );
 });
+
+test('fork is offered only for safe completed replies and hidden while streaming', () => {
+  const messages: ChatMessage[] = [
+    { id: 'u', role: 'user', content: 'hello', timestamp: 1 },
+    { id: 'done', role: 'assistant', content: 'completed', timestamp: 2, executionStatus: 'completed' },
+    { id: 'failed', role: 'assistant', content: 'failed', timestamp: 3, executionStatus: 'failed' },
+  ];
+  const render = (isStreaming: boolean) => renderToStaticMarkup(
+    <I18nProvider locale="en">
+      <TooltipProvider>
+        <ChatMessageList messages={messages} isStreaming={isStreaming} onForkFromMessage={() => {}} />
+      </TooltipProvider>
+    </I18nProvider>,
+  );
+  assert.equal((render(false).match(/Fork from here/g) ?? []).length, 1);
+  assert.equal((render(true).match(/Fork from here/g) ?? []).length, 0);
+});

components/ai/ChatMessageList.tsx

@@ -6,10 +6,11 @@
  * No avatars. Thinking blocks are collapsible.
  */
 
-import { AlertCircle, BookOpen, FileText, RotateCcw, SquareTerminal, X, ZoomIn, ZoomOut } from 'lucide-react';
+import { AlertCircle, BookOpen, FileText, GitFork, RotateCcw, SquareTerminal, X, ZoomIn, ZoomOut } from 'lucide-react';
 import React, { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import { useI18n } from '../../application/i18n/I18nProvider';
-import type { ChatMessage, ToolCall as AgentToolCall } from '../../infrastructure/ai/types';
+import type { AISessionContextCompaction, ChatMessage, ToolCall as AgentToolCall } from '../../infrastructure/ai/types';
+import { getForkableMessageIds } from '../../domain/aiSessionFork';
 import { Dialog, DialogContent, DialogTitle } from '../ui/dialog';
 import {
   Conversation,
@@ -92,6 +93,10 @@ interface ChatMessageListProps {
   /** Active chat session ID — used to filter standalone MCP approval blocks */
   activeSessionId?: string | null;
   activeCompaction?: ActiveCompactionUi | null;
+  /** Stored compaction summary for the viewed session — fork boundaries must not fall inside its coverage. */
+  contextCompaction?: AISessionContextCompaction | null;
+  /** Present when the panel supports forking a conversation from a completed assistant response. */
+  onForkFromMessage?: (messageId: string) => void;
   notes?: VaultNote[];
   hosts?: Host[];
   snippets?: Snippet[];
@@ -160,6 +165,8 @@ export function buildCodexApprovalRenderPlan(
 const MESSAGE_RENDER_BATCH = 50;
 const MESSAGE_RENDER_STEP = 50;
 
+const EMPTY_FORKABLE_SET: ReadonlySet<string> = new Set();
+
 export function pruneResolvedApprovals(
   previous: ReadonlyMap<string, boolean>,
   messages: readonly ChatMessage[],
@@ -180,6 +187,8 @@ const ChatMessageList: React.FC<ChatMessageListProps> = ({
   isStreaming,
   activeSessionId,
   activeCompaction = null,
+  contextCompaction,
+  onForkFromMessage,
   notes = [],
   hosts = [],
   snippets = [],
@@ -399,6 +408,14 @@ const ChatMessageList: React.FC<ChatMessageListProps> = ({
     [messages],
   );
 
+  // "Fork from here" targets: completed assistant responses whose whole
+  // prefix is a safe fork boundary (fully resolved tool calls, stored
+  // compaction summary still accurate). Hidden entirely while a turn streams.
+  const forkableMessageIds = useMemo(() => {
+    if (!onForkFromMessage || isStreaming) return EMPTY_FORKABLE_SET;
+    return getForkableMessageIds({ messages, contextCompaction: contextCompaction ?? undefined });
+  }, [onForkFromMessage, isStreaming, messages, contextCompaction]);
+
   // While a jump target is active, re-resolve the tail against the current list
   // so streaming appends cannot slide the window past the selected message.
   const effectiveTailCount = activeJumpMessageId
@@ -798,6 +815,22 @@ const ChatMessageList: React.FC<ChatMessageListProps> = ({
                     </div>
                   </div>
                 )}
+
+                {/* Fork from here — copies the conversation up to this completed
+                    response into a new session. Only on safe boundaries; hidden
+                    while a turn streams (forkableMessageIds empty). */}
+                {!isUser && onForkFromMessage && forkableMessageIds.has(message.id) && (
+                  <div className="flex -mt-0.5 opacity-0 group-hover:opacity-100 focus-within:opacity-100">
+                    <button
+                      type="button"
+                      onClick={() => onForkFromMessage(message.id)}
+                      className="flex items-center gap-1 rounded-md px-1.5 py-0.5 text-[11px] text-muted-foreground/40 hover:text-foreground hover:bg-white/[0.05] transition-colors cursor-pointer"
+                    >
+                      <GitFork size={11} />
+                      <span>{t('ai.chat.forkFromHere')}</span>
+                    </button>
+                  </div>
+                )}
               </MessageContent>
             </Message>
           );
@@ -1042,6 +1075,8 @@ function areMessagesEqual(prev: ChatMessageListProps, next: ChatMessageListProps
   if (prev.onOpenVaultHost !== next.onOpenVaultHost) return false;
   if (prev.onOpenVaultSnippet !== next.onOpenVaultSnippet) return false;
   if (prev.onOpenVaultSection !== next.onOpenVaultSection) return false;
+  if (prev.onForkFromMessage !== next.onForkFromMessage) return false;
+  if (prev.contextCompaction !== next.contextCompaction) return false;
   if (prev.messages.length !== next.messages.length) return false;
   if (prev.messages === next.messages) return true;
 

components/notes/NotesManager.persistence.test.tsx

@@ -0,0 +1,336 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { register } from "node:module";
+import React, { act } from "react";
+import type { VaultNote } from "../../domain/models.ts";
+
+// JSDOM has no stylesheet loader. All editor/application JavaScript stays real.
+register(`data:text/javascript,${encodeURIComponent(`
+  export async function load(url, context, nextLoad) {
+    if (url.endsWith("/components/notes/noteMath.scss")) {
+      return { format: "module", source: "export {};", shortCircuit: true };
+    }
+    return nextLoad(url, context);
+  }
+`)}`, import.meta.url);
+
+// Same browser shims as InlineMarkdownEditor.unrenderableMarkdown.test.tsx.
+import {JSDOM} from "jsdom";
+const setupDom = () => {
+  const dom = new JSDOM('<!doctype html><html><body><div id="root"></div></body></html>', {
+    pretendToBeVisual: true,
+    url: "http://localhost",
+  });
+  const window = dom.window;
+  const previousGlobals = new Map<string, PropertyDescriptor | undefined>();
+  const installGlobal = (key: string, value: unknown) => {
+    previousGlobals.set(key, Object.getOwnPropertyDescriptor(globalThis, key));
+    Object.defineProperty(globalThis, key, { configurable: true, writable: true, value });
+  };
+
+  class ResizeObserverStub {
+    observe() {}
+    unobserve() {}
+    disconnect() {}
+  }
+
+  function LoadedImageStub() {
+    const image = window.document.createElement("img");
+    Object.defineProperty(image, "src", {
+      get: () => image.getAttribute("src") ?? "",
+      set: (src: string) => {
+        image.setAttribute("src", src);
+        queueMicrotask(() => image.dispatchEvent(new window.Event("load")));
+      },
+    });
+    return image;
+  }
+
+  Object.assign(window.Range.prototype, {
+    getClientRects: () => [],
+    getBoundingClientRect: () => new window.DOMRect(),
+  });
+
+  // CodeMirror needs these browser APIs when the full note contains code blocks.
+  window.matchMedia = (query: string) => ({
+    matches: false,
+    media: query,
+    onchange: null,
+    addListener() {},
+    removeListener() {},
+    addEventListener() {},
+    removeEventListener() {},
+    dispatchEvent: () => false,
+  });
+
+  for (const [key, value] of Object.entries({
+    window,
+    Window: window.Window,
+    Image: LoadedImageStub,
+    document: window.document,
+    navigator: window.navigator,
+    HTMLElement: window.HTMLElement,
+    HTMLImageElement: window.HTMLImageElement,
+    HTMLInputElement: window.HTMLInputElement,
+    HTMLTextAreaElement: window.HTMLTextAreaElement,
+    HTMLSelectElement: window.HTMLSelectElement,
+    Element: window.Element,
+    SVGElement: window.SVGElement,
+    Node: window.Node,
+    DocumentFragment: window.DocumentFragment,
+    Range: window.Range,
+    NodeFilter: window.NodeFilter,
+    MutationObserver: window.MutationObserver,
+    CustomEvent: window.CustomEvent,
+    DOMRect: window.DOMRect,
+    Event: window.Event,
+    KeyboardEvent: window.KeyboardEvent,
+    MouseEvent: window.MouseEvent,
+    getComputedStyle: window.getComputedStyle.bind(window),
+    requestAnimationFrame: window.requestAnimationFrame.bind(window),
+    cancelAnimationFrame: window.cancelAnimationFrame.bind(window),
+    ResizeObserver: ResizeObserverStub,
+    IS_REACT_ACT_ENVIRONMENT: true,
+  })) {
+    installGlobal(key, value);
+  }
+
+  return {
+    window,
+    cleanup() {
+      for (const [key, descriptor] of previousGlobals) {
+        if (descriptor) Object.defineProperty(globalThis, key, descriptor);
+        else delete (globalThis as Record<string, unknown>)[key];
+      }
+      dom.window.close();
+    },
+  };
+};
+
+for (const mode of ["source", "edit"] as const) {
+  test(`mounted notes ${mode}: failed save retains both versions through retry and switching`, { timeout: 30_000 }, async (t) => {
+    const { window, cleanup } = setupDom();
+    // The app initializes unrelated vault collections under Web Locks. Serialize
+    // those calls in the fixture too (Node 22 does not always expose Web Locks).
+    const tails = new Map<string, Promise<unknown>>();
+    Object.defineProperty(window.navigator, "locks", { value: {
+      request(name: string, callback: () => unknown) {
+        const run = (tails.get(name) ?? Promise.resolve()).then(callback, callback);
+        tails.set(name, run.then(() => undefined, () => undefined));
+        return run;
+      },
+    } });
+    const previousStorage = Object.getOwnPropertyDescriptor(globalThis, "localStorage");
+    Object.defineProperty(globalThis, "localStorage", { configurable: true, value: window.localStorage });
+    const keys = await import("../../infrastructure/config/storageKeys.ts");
+    for (const [name, key] of Object.entries(keys)) {
+      if (name.startsWith("STORAGE_KEY_") && typeof key === "string") window.localStorage.setItem(key, "[]");
+    }
+    const original: VaultNote = { id: "synthetic-note", title: "Synthetic note", content: "Persisted baseline", createdAt: 1, updatedAt: 1, order: 0 };
+    const second: VaultNote = { ...original, id: "second-note", title: "Second note", content: "Second body", order: 1 };
+    window.localStorage.setItem(keys.STORAGE_KEY_NOTES, JSON.stringify([original, second]));
+    window.localStorage.setItem(keys.STORAGE_KEY_VAULT_NOTES_EDITOR_MODE, mode);
+    const { useVaultState } = await import("../../application/state/useVaultState.ts");
+    const { getNotesSnapshot, subscribeNotes } = await import("../../application/state/notesStore.ts");
+    const { setNotify } = await import("../../application/notification.ts");
+    const { I18nProvider } = await import("../../application/i18n/I18nProvider.tsx");
+    const { TooltipProvider } = await import("../ui/tooltip.tsx");
+    const { NotesManager } = await import("./NotesManager.tsx");
+    const { createRoot } = await import("react-dom/client");
+    const rootNode = window.document.getElementById("root")!;
+    const root = createRoot(rootNode);
+    let vault!: ReturnType<typeof useVaultState>;
+    let openNote!: React.Dispatch<React.SetStateAction<string>>;
+    const saveResults: boolean[] = [];
+    const notices: string[] = [];
+    let quota = false;
+    const realSetItem = window.Storage.prototype.setItem;
+    window.Storage.prototype.setItem = function (key: string, value: string) {
+      if (quota && key === keys.STORAGE_KEY_NOTES) throw new DOMException("Synthetic quota exceeded", "QuotaExceededError");
+      return realSetItem.call(this, key, value);
+    };
+    setNotify({ error: message => notices.push(message), info: () => {}, warning: () => {}, success: () => {} });
+    function App() {
+      const state = useVaultState();
+      vault = state;
+      const [noteId, setNoteId] = React.useState(original.id);
+      openNote = setNoteId;
+      const updateNotes = state.updateNotes;
+      const save = React.useCallback((notes: VaultNote[]) => {
+        const result = updateNotes(notes);
+        saveResults.push(result);
+        return result;
+      }, [updateNotes]);
+      return <I18nProvider locale="en"><TooltipProvider><NotesManager notes={state.notes} noteGroups={state.noteGroups}
+        hosts={[]} onUpdateNotes={save} onUpdateNoteGroups={state.updateNoteGroups} displayMode="full" openNoteId={noteId} />
+      </TooltipProvider></I18nProvider>;
+    }
+    const editor = () => mode === "source" ? rootNode.querySelector<HTMLTextAreaElement>("textarea") : rootNode.querySelector<HTMLElement>('[contenteditable="true"]');
+    const visible = () => (mode === "source" ? (editor() as HTMLTextAreaElement)?.value : editor()?.textContent)?.trim();
+    const waitFor = async (check: () => boolean, label: string) => {
+      const deadline = Date.now() + 6000;
+      while (!check()) {
+        assert.ok(Date.now() < deadline, `${label}; saves=${JSON.stringify(saveResults)}, visible=${visible()}, notes=${JSON.stringify(vault.notes)}`);
+        await act(async () => { await new Promise(resolve => setTimeout(resolve, 20)); });
+      }
+    };
+    const persisted = (): VaultNote[] => JSON.parse(window.localStorage.getItem(keys.STORAGE_KEY_NOTES)!);
+    const primary = () => vault.notes.find(note => note.id === original.id)!;
+    const edit = async (content: string) => {
+      await act(async () => {
+        if (mode === "source") {
+          const textarea = editor() as HTMLTextAreaElement;
+          Object.getOwnPropertyDescriptor(window.HTMLTextAreaElement.prototype, "value")!.set!.call(textarea, content);
+          textarea.dispatchEvent(new window.Event("input", { bubbles: true }));
+        } else {
+          const lexical = await import("lexical");
+          const instance = lexical.getNearestEditorFromDOMNode(editor()!);
+          assert.ok(instance);
+          instance.update(() => { lexical.$getRoot().clear().append(lexical.$createParagraphNode().append(lexical.$createTextNode(content))); }, { discrete: true });
+        }
+      });
+      await waitFor(() => visible() === content, "local edit is visible");
+    };
+    const incoming = async (notes: VaultNote[]) => {
+      const value = JSON.stringify(notes);
+      // Independent writer bypasses only our synthetic quota failure.
+      realSetItem.call(window.localStorage, keys.STORAGE_KEY_NOTES, value);
+      await act(async () => { window.dispatchEvent(new window.StorageEvent("storage", { key: keys.STORAGE_KEY_NOTES, newValue: value, storageArea: window.localStorage })); });
+    };
+    try {
+      await act(async () => root.render(<App />));
+      await waitFor(() => vault.isInitialized && visible() === original.content, "initial editor");
+      await edit("Successfully saved");
+      await waitFor(() => saveResults.length === 1, "normal successful debounce");
+      assert.equal(saveResults[0], true);
+      assert.equal(persisted()[0].content.trim(), "Successfully saved");
+      await incoming([{ ...original, content: "Legitimate external update", updatedAt: 5 }, second]);
+      await waitFor(() => visible() === "Legitimate external update", "external update after successful save");
+
+      quota = true;
+      const local = "Unsaved local draft";
+      await edit(local);
+      assert.equal(saveResults.length, 1, "dirty control precedes autosave echo");
+      await incoming([{ ...original, content: "Remote before echo", updatedAt: 10 }, second]);
+      assert.equal(primary().content, "Remote before echo");
+      assert.equal(visible(), local, "existing editor dirty guard works before echo");
+      await waitFor(() => saveResults.length === 2 && primary().content.trim() === local, "failed save optimistic echo");
+      assert.equal(saveResults[1], false);
+      assert.equal(notices.length, 1);
+      assert.equal(persisted()[0].content, "Remote before echo");
+      assert.ok(primary().updatedAt > 11, "incoming timestamps deliberately run behind local time");
+      const remote = [{ ...original, content: "Remote after echo", updatedAt: 11 }, second];
+      await incoming(remote);
+      assert.equal(visible(), local, "failed optimistic echo must not acknowledge durability");
+      assert.equal(primary().content.trim(), local);
+      assert.equal(getNotesSnapshot().notes.find(note => note.id === original.id)!.content.trim(), local);
+      const copy = vault.notes.find(note => note.id !== original.id && note.content === "Remote after echo");
+      assert.ok(copy, "external conflicting content must remain accessible as a note");
+      const copyId = copy.id;
+
+      await incoming(remote);
+      assert.equal(vault.notes.length, 3, "repeated storage delivery creates no duplicate copy");
+      await edit("Unsaved local draft revision two");
+      await waitFor(() => saveResults.length === 3, "second failed debounce");
+      assert.equal(saveResults[2], false);
+      assert.equal(notices.length, 1, "repeated failure respects notification throttling");
+      await act(async () => openNote(second.id));
+      await waitFor(() => visible() === second.content, "switch to second note");
+      await act(async () => openNote(original.id));
+      await waitFor(() => visible() === "Unsaved local draft revision two", "switch back retains failed draft");
+      // Switching notes intentionally defers the content swap by two frames.
+      await act(async () => { await new Promise(resolve => window.requestAnimationFrame(() => window.requestAnimationFrame(resolve))); });
+      assert.equal(vault.notes.find(note => note.id === copyId)?.content, "Remote after echo");
+
+      quota = false;
+      await edit("Durable recovered draft");
+      await waitFor(() => saveResults.length === 4, "successful retry");
+      assert.equal(saveResults[3], true);
+      assert.equal(persisted().find(note => note.id === original.id)?.content.trim(), "Durable recovered draft");
+      assert.equal(persisted().find(note => note.id === copyId)?.content, "Remote after echo");
+      const afterSuccess = persisted().map(note => note.id === original.id ? { ...note, content: "External after recovery", updatedAt: 2 } : note);
+      await incoming(afterSuccess);
+      await waitFor(() => visible() === "External after recovery", "successful same-generation save releases pending protection");
+      assert.equal(vault.notes.length, 3);
+
+      await act(async () => { window.dispatchEvent(new window.StorageEvent("storage", {
+        key: keys.STORAGE_KEY_NOTES, newValue: JSON.stringify(remote), storageArea: window.localStorage,
+      })); });
+      assert.equal(visible(), "External after recovery", "queued obsolete storage events must not roll back a successful save");
+
+      // Publishing a successful generation can synchronously trigger another
+      // write. The older acknowledgement must never clear the newer failure.
+      let nestedResult: boolean | undefined;
+      let triggered = false;
+      const unsubscribe = subscribeNotes(() => {
+        if (triggered) return;
+        triggered = true;
+        quota = true;
+        nestedResult = vault.updateNotes(getNotesSnapshot().notes.map(note => note.id === original.id ? { ...note, content: "Newer failed generation" } : note));
+      });
+      try {
+        await act(async () => {
+          assert.equal(vault.updateNotes(vault.notes.map(note => note.id === original.id ? { ...note, content: "Older successful generation" } : note)), true);
+        });
+      } finally { unsubscribe(); }
+      assert.equal(nestedResult, false);
+      await incoming(persisted().map(note => note.id === original.id ? { ...note, content: "Concurrent with newer failure" } : note));
+      assert.equal(primary().content, "Newer failed generation");
+      assert.ok(vault.notes.some(note => note.content === "Concurrent with newer failure"));
+
+      // Full-snapshot replacement (clear/restore) remains explicit and does not
+      // accidentally resurrect a disk-only note through the save-time rebase.
+      quota = false;
+      realSetItem.call(window.localStorage, keys.STORAGE_KEY_NOTES, JSON.stringify([...persisted(), { ...second, id: "disk-only" }]));
+      await act(async () => { assert.equal(vault.updateNotes([original], { replace: true }), true); });
+      assert.deepEqual(persisted().map(note => note.id), [original.id]);
+
+      for (const operation of ["clear", "import"] as const) {
+        await t.test(`failed ${operation} retains replacement ownership through events and retry`, async () => {
+          quota = false;
+          await act(async () => { assert.equal(vault.updateNotes([original, second], { replace: true }), true); });
+          const replacement = operation === "clear" ? [] : [{ ...original, content: "Imported snapshot" }];
+          quota = true;
+          await act(async () => {
+            if (operation === "clear") vault.clearVaultData();
+            else await vault.importDataFromString(JSON.stringify({ notes: replacement }));
+          });
+          const contents = (notes: VaultNote[]) => notes.map(({ id, content }) => [id, content]);
+          assert.deepEqual(contents(vault.notes), contents(replacement));
+          assert.deepEqual(contents(persisted()), contents([original, second]), "replacement has not reached disk");
+          const peer = [
+            { ...original, content: "Changed in another window", updatedAt: 30 }, second,
+            { ...second, id: "peer-added", content: "Added in another window" },
+          ];
+          await incoming(peer);
+          assert.deepEqual(contents(vault.notes), contents(replacement), "failed replacement must not adopt peer edits or additions");
+          assert.deepEqual(contents(getNotesSnapshot().notes), contents(replacement));
+
+          const edited = operation === "clear"
+            ? [{ ...original, id: "created-after-clear", content: "New local note" }]
+            : replacement.map(note => ({ ...note, content: "Edited after import" }));
+          await act(async () => { assert.equal(vault.updateNotes(edited), false); });
+          await incoming([...peer, { ...second, id: "peer-added-again" }]);
+          assert.deepEqual(contents(vault.notes), contents(edited), "an ordinary failed edit must inherit replacement ownership");
+
+          // Also cover a peer write whose storage event has not arrived yet.
+          realSetItem.call(window.localStorage, keys.STORAGE_KEY_NOTES, JSON.stringify([...peer, { ...second, id: "unobserved-peer" }]));
+          quota = false;
+          await act(async () => { assert.equal(vault.updateNotes(vault.notes), true); });
+          assert.deepEqual(contents(persisted()), contents(edited), "successful retry persists only the replacement catalog");
+          const afterReplacement = [{ ...second, id: "legitimate-later-peer" }];
+          await incoming(afterReplacement);
+          assert.deepEqual(contents(vault.notes), contents(afterReplacement), "successful current owner releases replacement protection");
+        });
+      }
+      console.log(`NOTES_FIX_${mode.toUpperCase()}: success, dirty-before-echo, failed-echo conflict, duplicate delivery, repeated failure, switch, retry, legal external update passed`);
+    } finally {
+      await act(async () => root.unmount());
+      window.Storage.prototype.setItem = realSetItem;
+      setNotify({ error: () => {}, info: () => {}, warning: () => {}, success: () => {} });
+      if (previousStorage) Object.defineProperty(globalThis, "localStorage", previousStorage);
+      else delete (globalThis as Record<string, unknown>).localStorage;
+      cleanup();
+    }
+  });
+}

components/scripts/ScriptEditorModal.tsx

@@ -200,6 +200,7 @@ export const ScriptEditorModal: React.FC<ScriptEditorModalProps> = ({
         customGroups={customGroups}
         selectedHostIds={selectedHostIds}
         multiSelect
+        allowLocalHosts={true}
         onSelect={onSelectHost}
         onSelectionChange={onSelectionChange}
         onConfirm={handleTargetsConfirm}

components/settings/tabs/SettingsShortcutsTab.test.tsx

@@ -0,0 +1,86 @@
+import assert from "node:assert/strict";
+import test, { type TestContext } from "node:test";
+import React from "react";
+import { DEFAULT_KEY_BINDINGS } from "../../../domain/models/keyBindings";
+import { createDomRenderer, dispatchDomEvent, installDomEnvironment } from "../../test-support/renderReactDom";
+
+async function setup(t: TestContext, label: string) {
+  const env = installDomEnvironment();
+  const previous = new Map<string, PropertyDescriptor | undefined>();
+  const globals = {
+    DocumentFragment: env.window.DocumentFragment,
+    MutationObserver: env.window.MutationObserver,
+    Element: env.window.Element,
+    requestAnimationFrame: (callback: FrameRequestCallback) => setTimeout(() => callback(Date.now()), 0),
+    cancelAnimationFrame: clearTimeout,
+  };
+  for (const [key, value] of Object.entries(globals)) {
+    previous.set(key, Object.getOwnPropertyDescriptor(globalThis, key));
+    Object.defineProperty(globalThis, key, { configurable: true, writable: true, value });
+  }
+  const { default: SettingsShortcutsTab } = await import("./SettingsShortcutsTab");
+  const { I18nProvider } = await import("../../../application/i18n/I18nProvider");
+  const { Tabs } = await import("../../ui/tabs");
+  const renderer = await createDomRenderer(env.document);
+  t.after(async () => {
+    await renderer.unmount();
+    for (const [key, descriptor] of previous) {
+      if (descriptor) Object.defineProperty(globalThis, key, descriptor);
+      else Reflect.deleteProperty(globalThis, key);
+    }
+    env.cleanup();
+  });
+  const updates: string[][] = [];
+  await renderer.render(<I18nProvider locale="en"><Tabs value="shortcuts"><SettingsShortcutsTab
+    hotkeyScheme="pc" setHotkeyScheme={() => {}}
+    shellOnlyTabNumberShortcuts={false} setShellOnlyTabNumberShortcuts={() => {}}
+    showTabNumberBadges={true} setShowTabNumberBadges={() => {}}
+    disableTerminalFontZoom={false} setDisableTerminalFontZoom={() => {}}
+    keyBindings={DEFAULT_KEY_BINDINGS} resetAllKeyBindings={() => {}}
+    updateKeyBinding={(...args) => { updates.push(args); }}
+  /></Tabs></I18nProvider>);
+  const row = [...env.document.querySelectorAll("span")].find((span) => span.textContent === label)?.parentElement;
+  const button = row?.querySelector("button");
+  assert.ok(button);
+  await dispatchDomEvent(button, new env.window.MouseEvent("click", { bubbles: true }));
+  const key = (type: "keydown" | "keyup", init: KeyboardEventInit) => dispatchDomEvent(
+    env.window, new env.window.KeyboardEvent(type, { bubbles: true, cancelable: true, ...init }),
+  );
+  return { updates, key, button };
+}
+
+test("the tab modifier editor saves left Alt on release without requiring a digit", async (t) => {
+  const { updates, key } = await setup(t, "Switch to Tab [1...9]");
+  await key("keydown", { key: "Alt", code: "AltLeft", altKey: true });
+  assert.deepEqual(updates, []);
+  await key("keyup", { key: "Alt", code: "AltLeft" });
+  assert.deepEqual(updates, [["switch-tab-1-9", "pc", "Alt + [1...9]"]]);
+});
+
+test("the modifier editor waits for the full modifier chord to be released", async (t) => {
+  const { updates, key } = await setup(t, "Switch to Tab [1...9]");
+  await key("keydown", { key: "Control", ctrlKey: true });
+  await key("keydown", { key: "Alt", ctrlKey: true, altKey: true });
+  await key("keyup", { key: "Alt", ctrlKey: true });
+  assert.deepEqual(updates, []);
+  await key("keyup", { key: "Control" });
+  assert.deepEqual(updates, [["switch-tab-1-9", "pc", "Ctrl + Alt + [1...9]"]]);
+});
+
+test("ordinary shortcuts still require a non-modifier key", async (t) => {
+  const { updates, key } = await setup(t, "Next Tab");
+  await key("keydown", { key: "Alt", altKey: true });
+  await key("keyup", { key: "Alt" });
+  assert.deepEqual(updates, []);
+  await key("keydown", { key: "ArrowRight", altKey: true });
+  assert.deepEqual(updates, [["next-tab", "pc", "Alt + \u2192"]]);
+});
+
+test("Escape cancels an unfinished modifier recording", async (t) => {
+  const { updates, key, button } = await setup(t, "Switch to Tab [1...9]");
+  await key("keydown", { key: "Alt", altKey: true });
+  await key("keydown", { key: "Escape", altKey: true });
+  await key("keyup", { key: "Alt" });
+  assert.deepEqual(updates, []);
+  assert.equal(button.textContent, "Ctrl");
+});

components/settings/tabs/SettingsShortcutsTab.tsx

@@ -64,6 +64,7 @@ export default function SettingsShortcutsTab(props: {
     if (!recordingBindingId || !recordingScheme) return;
 
     const specialSuffix = getSpecialSuffix(recordingBindingId);
+    let pendingModifierBinding: string | null = null;
 
     const handleKeyDown = (e: KeyboardEvent) => {
       // Skip while app lock overlay is up so password keys never bind (Codex P2).
@@ -77,8 +78,6 @@ export default function SettingsShortcutsTab(props: {
       }
 
       if (specialSuffix) {
-        if (["Meta", "Control", "Alt", "Shift"].includes(e.key)) return;
-
         const parts: string[] = [];
         if (recordingScheme === "mac") {
           if (e.metaKey) parts.push("⌘");
@@ -95,6 +94,11 @@ export default function SettingsShortcutsTab(props: {
         const modifierString = parts.length > 0 ? `${parts.join(" + ")} + ` : "";
         const fullKeyString = modifierString + specialSuffix;
 
+        if (["Meta", "Control", "Alt", "Shift"].includes(e.key)) {
+          pendingModifierBinding = fullKeyString;
+          return;
+        }
+
         updateKeyBinding?.(recordingBindingId, recordingScheme, fullKeyString);
         cancelRecording();
         return;
@@ -106,6 +110,17 @@ export default function SettingsShortcutsTab(props: {
       cancelRecording();
     };
 
+    const handleKeyUp = (e: KeyboardEvent) => {
+      if (!specialSuffix || !pendingModifierBinding || isAppLockOverlayActive()) return;
+      if (!["Meta", "Control", "Alt", "Shift"].includes(e.key)) return;
+      e.preventDefault();
+      e.stopPropagation();
+      // Wait for release so a modifier-only editor can capture Ctrl+Alt, etc.
+      if (e.metaKey || e.ctrlKey || e.altKey || e.shiftKey) return;
+      updateKeyBinding?.(recordingBindingId, recordingScheme, pendingModifierBinding);
+      cancelRecording();
+    };
+
     const handleClick = () => {
       cancelRecording();
     };
@@ -115,9 +130,11 @@ export default function SettingsShortcutsTab(props: {
     }, 100);
 
     window.addEventListener("keydown", handleKeyDown, true);
+    window.addEventListener("keyup", handleKeyUp, true);
     return () => {
       clearTimeout(timer);
       window.removeEventListener("keydown", handleKeyDown, true);
+      window.removeEventListener("keyup", handleKeyUp, true);
       window.removeEventListener("click", handleClick, true);
     };
   }, [recordingBindingId, recordingScheme, updateKeyBinding, cancelRecording, getSpecialSuffix]);

components/sftp/SftpHostPicker.tsx

@@ -10,7 +10,7 @@ import {
     sftpSourceSessionIdForHost,
     type SftpConnectedHostEntry,
 } from '../../domain/sftpConnectedHosts';
-import { isPluginHostProtocol } from '../../domain/pluginConnection';
+import { canOpenDualPaneSftp } from '../../domain/sftpDualPaneOpen';
 import { Host } from '../../types';
 import { DistroAvatar } from '../DistroAvatar';
 import { getQuickSwitcherRowStateClass, shouldUseQuickSwitcherPointerNavigation } from '../QuickSwitcher';
@@ -95,9 +95,11 @@ const SftpHostPickerInner: React.FC<SftpHostPickerProps> = ({
 
     const filteredHosts = useMemo(() => {
         return hosts.filter((h) => {
-            // SFTP is an SSH-specific host capability. Plugin protocols may
-            // provide arbitrary transports and cannot be treated as SSH.
-            if (h.protocol === "serial" || isPluginHostProtocol(h.protocol)) return false;
+            // SFTP is an SSH-specific host capability. Reuse the dual-pane
+            // opener's predicate so serial, local-shell (no SSH channel —
+            // selecting one would SSH into localhost) and plugin protocols
+            // are excluded the same way everywhere.
+            if (!canOpenDualPaneSftp(h)) return false;
             // Hide a saved host only when Connected already shows the same endpoint.
             // If the vault host was edited after connect, keep both: Live (old) + Saved (new).
             const connected = connectedByHostId.get(h.id);

components/terminal/AutocompletePopup.hover.test.tsx

@@ -1,6 +1,7 @@
 import test from "node:test";
 import assert from "node:assert/strict";
 import { JSDOM } from "jsdom";
+import { reconcileAutocompletePopupState, type AutocompleteState } from "./autocomplete/useTerminalAutocomplete.ts";
 
 /**
  * Regression test for #3426: hovering autocomplete rows must not change the
@@ -10,7 +11,7 @@ import { JSDOM } from "jsdom";
  * the hovered row and self-oscillating (violent mousemove jitter).
  */
 
-test("autocomplete popup keeps a fixed geometry while hovering rows (#3426)", async () => {
+test("autocomplete popup keeps a fixed geometry while hovering rows (#3426)", async (t) => {
   const dom = new JSDOM('<!doctype html><html><body><div id="root"></div></body></html>', {
     pretendToBeVisual: true,
     url: "http://localhost",
@@ -194,6 +195,38 @@ test("autocomplete popup keeps a fixed geometry while hovering rows (#3426)", as
       }
     }
 
+    await t.test("edited snippet rows cannot be clicked before the provider refresh", async () => {
+      let clicks = 0;
+      const state: AutocompleteState = {
+        suggestions: [{ text: "deploy", displayText: "deploy", source: "snippet", score: 2000,
+          snippet: { id: "deploy", label: "deploy", command: "echo deploy" } }],
+        selectedIndex: -1, popupVisible: true,
+        popupAnchorViewport: { left: 100, top: 300, bottom: 316 },
+        expandUpward: false, subDirPanels: [], subDirFocusLevel: -1,
+      };
+      const renderPopup = async (next: AutocompleteState) => {
+        await act(async () => {
+          root.render(<AutocompletePopup
+            suggestions={next.suggestions} selectedIndex={next.selectedIndex}
+            anchorViewport={next.popupAnchorViewport} visible={next.popupVisible}
+            onSelect={() => { clicks++; }} containerRef={containerRef}
+          />);
+        });
+      };
+      await renderPopup(state);
+      const label = Array.from(rootNode.querySelectorAll<HTMLElement>("span"))
+        .find((el) => el.textContent === "deploy");
+      const row = label?.closest<HTMLElement>("div[style*='cursor']");
+      assert.ok(row);
+      await act(async () => {
+        row.dispatchEvent(new window.MouseEvent("mousedown", { bubbles: true }));
+      });
+      assert.equal(clicks, 1, "an unselected fresh snippet is clickable");
+      await renderPopup(reconcileAutocompletePopupState(state, "git pull xyz"));
+      assert.equal(Boolean(rootNode.querySelector(".xterm-autocomplete-popup")), false);
+      assert.equal(clicks, 1);
+    });
+
     await act(async () => {
       root.unmount();
     });

components/terminal/autocomplete/completionEngine.ts

@@ -406,16 +406,32 @@ export async function getCompletions(
     }
   }
 
-  // Snippets: only at the command position (typing the command name).
+  // Snippets: at the command position the whole typed line is the needle. Once
+  // arguments are present, match against the word being typed so a snippet
+  // (e.g. an email shortcut) stays reachable after a command like `git pull `
+  // (#3622). Argument-position matching is prefix-only, needs at least two
+  // typed characters, and yields when path completion owns the slot.
   // Push without the early seen-text skip: snippets score above history, so if
   // a snippet's label collides with an existing history entry's text, the
   // score-sort + final dedup below keeps the snippet (the higher-scored one).
-  if (options.snippets && options.snippets.length > 0 && ctx.wordIndex === 0) {
-    for (const snippetSuggestion of getSnippetSuggestions(input, options.snippets, {
-      hostId,
-      hostGroup: options.hostGroup,
-    })) {
-      suggestions.push(snippetSuggestion);
+  if (options.snippets && options.snippets.length > 0) {
+    const atCommandPosition = ctx.wordIndex === 0;
+    const argumentNeedle = normalizeHistoryPathPrefix(ctx.currentWord);
+    const snippetArgumentMatch = !atCommandPosition
+      && !preferPathSuggestions
+      && argumentNeedle.trim().length >= 2;
+    if (atCommandPosition || snippetArgumentMatch) {
+      for (const snippetSuggestion of getSnippetSuggestions(
+        atCommandPosition ? input : argumentNeedle,
+        options.snippets,
+        {
+          hostId,
+          hostGroup: options.hostGroup,
+          prefixOnly: !atCommandPosition,
+        },
+      )) {
+        suggestions.push(snippetSuggestion);
+      }
     }
   }
 

components/terminal/autocomplete/snippetCompleter.ts

@@ -8,7 +8,7 @@
  */
 import type { Snippet } from "../../../domain/models";
 import { snippetAppliesToHost } from "../../../domain/snippetTargets";
-import { matchesSearchQuery } from "../../../lib/searchMatcher";
+import { matchesSearchQuery, matchesWordPrefixQuery } from "../../../lib/searchMatcher";
 import type { CompletionSuggestion } from "./completionEngine";
 
 const SNIPPET_BASE_SCORE = 2000; // Above history (1000+freq) per "snippet > history".
@@ -30,7 +30,7 @@ function snippetAvailableForAutocomplete(
 export function getSnippetSuggestions(
   input: string,
   snippets: Snippet[],
-  options: { hostId?: string; hostGroup?: string } = {},
+  options: { hostId?: string; hostGroup?: string; prefixOnly?: boolean } = {},
 ): CompletionSuggestion[] {
   const needle = input.trim().toLowerCase();
   if (!needle || !Array.isArray(snippets)) return [];
@@ -44,10 +44,16 @@ export function getSnippetSuggestions(
     const labelPrefix = label.startsWith(needle);
     // Literal prefix/substring first (cheap); fall back to shared smart matcher
     // so Chinese titles surface for pinyin / initials the same way host search does.
-    const matches = labelPrefix
-      || label.includes(needle)
-      || firstLine.startsWith(needle)
-      || matchesSearchQuery(needle, snippet.label, firstLine);
+    // In prefixOnly mode (argument position), matches must start at a word
+    // boundary to avoid flooding mid-argument popups; pinyin still applies.
+    const matches = options.prefixOnly
+      ? labelPrefix
+        || firstLine.startsWith(needle)
+        || matchesWordPrefixQuery(needle, snippet.label, firstLine)
+      : labelPrefix
+        || label.includes(needle)
+        || firstLine.startsWith(needle)
+        || matchesSearchQuery(needle, snippet.label, firstLine);
     if (!matches) continue;
 
     out.push({

components/terminal/autocomplete/useTerminalAutocomplete.ts

@@ -144,8 +144,8 @@ function isSubsequence(query: string, target: string): boolean {
 
 /**
  * Remove history rows that no longer match the edited input while a debounced
- * provider refresh is pending. Other sources keep their provider-specific
- * matching semantics (snippet search, plugin replacement, etc.).
+ * provider refresh is pending. Snippets must be re-queried for the new input
+ * before they can be selected or executed. Other sources retain their matching.
  */
 export function reconcileAutocompletePopupState(
   prev: AutocompleteState,
@@ -158,6 +158,7 @@ export function reconcileAutocompletePopupState(
   const inputContext = parseCommandLine(input);
   const allowFuzzyHistory = input.length >= 2 && inputContext.wordIndex === 0;
   const suggestions = prev.suggestions.filter((suggestion) => {
+    if (suggestion.source === "snippet") return false;
     if (suggestion.source !== "history") return true;
     const text = suggestion.text.toLowerCase();
     if (suggestion.historyMatch === "path-argument") {

components/terminal/completionEngineSnippets.test.ts

@@ -14,8 +14,28 @@ test("getCompletions includes snippet suggestions at the command position", asyn
   assert.equal(snip?.displayText, "deploy");
 });
 
-test("getCompletions does not surface snippets past the command position", async () => {
-  const out = await getCompletions("git dep", { snippets: [deploySnippet] });
+test("getCompletions surfaces prefix-matching snippets while typing an argument (#3622)", async () => {
+  const out = await getCompletions("git pull dep", { snippets: [deploySnippet] });
+  const snip = out.find((s) => s.source === "snippet");
+  assert.ok(snip, "expected a snippet suggestion while typing an argument");
+  assert.equal(snip?.displayText, "deploy");
+});
+
+test("getCompletions does not surface snippets for mid-word argument matches", async () => {
+  // Argument-position matching works on word boundaries only: "mai" sits
+  // mid-word in "gmail" and must not surface the snippet.
+  const substringSnippet: Snippet = { id: "gm", label: "gmail", command: "echo gmail" };
+  const out = await getCompletions("git push mai", { snippets: [substringSnippet] });
+  assert.equal(out.find((s) => s.source === "snippet"), undefined);
+});
+
+test("getCompletions does not surface snippets for single-character arguments", async () => {
+  const out = await getCompletions("git pull d", { snippets: [deploySnippet] });
+  assert.equal(out.find((s) => s.source === "snippet"), undefined);
+});
+
+test("getCompletions yields argument-position snippets to path completion", async () => {
+  const out = await getCompletions("cat dep", { snippets: [deploySnippet] });
   assert.equal(out.find((s) => s.source === "snippet"), undefined);
 });
 

components/terminal/restoreWindowResizeFocus.test.ts

@@ -0,0 +1,258 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import {
+  attachWindowResizeFocusRestore,
+  WINDOW_RESIZE_RESTORE_FOCUS_DELAY_MS,
+  type MinimalDocument,
+} from "./restoreWindowResizeFocus";
+
+type FakeWindow = {
+  listeners: Map<string, Array<() => void>>;
+  addEventListener: (type: string, listener: () => void) => void;
+  removeEventListener: (type: string, listener: () => void) => void;
+  emit: (type: string) => void;
+};
+
+const createWindowStub = (): FakeWindow => {
+  const listeners = new Map<string, Array<() => void>>();
+  return {
+    listeners,
+    addEventListener(type, listener) {
+      const bucket = listeners.get(type) ?? [];
+      bucket.push(listener);
+      listeners.set(type, bucket);
+    },
+    removeEventListener(type, listener) {
+      const bucket = listeners.get(type) ?? [];
+      const index = bucket.indexOf(listener);
+      if (index >= 0) bucket.splice(index, 1);
+    },
+    emit(type) {
+      for (const listener of [...(listeners.get(type) ?? [])]) listener();
+    },
+  };
+};
+
+type SchedulerState = {
+  schedule: (callback: () => void, delay: number) => number;
+  cancel: (id: number) => void;
+  runNext: () => void;
+  pendingCount: () => number;
+};
+
+const createScheduler = (): SchedulerState => {
+  type Entry = { id: number; callback: () => void; cancelled: boolean };
+  const queue: Entry[] = [];
+  let nextId = 1;
+  return {
+    schedule(callback, delay) {
+      assert.equal(delay, WINDOW_RESIZE_RESTORE_FOCUS_DELAY_MS);
+      queue.push({ id: nextId, callback, cancelled: false });
+      return nextId++;
+    },
+    cancel(id) {
+      for (const entry of queue) {
+        if (entry.id === id) entry.cancelled = true;
+      }
+    },
+    runNext() {
+      while (queue.length) {
+        const entry = queue.shift()!;
+        if (!entry.cancelled) {
+          entry.callback();
+          return;
+        }
+      }
+    },
+    pendingCount: () => queue.filter((entry) => !entry.cancelled).length,
+  };
+};
+
+test("resize restores terminal focus once the resize settles", () => {
+  const win = createWindowStub();
+  const scheduler = createScheduler();
+  let refocusCalls = 0;
+  const detach = attachWindowResizeFocusRestore({
+    win,
+    doc: { querySelector: () => null, hasFocus: () => true } as MinimalDocument,
+    refocus: () => { refocusCalls += 1; },
+    scheduleTimeout: scheduler.schedule,
+    cancelTimeout: scheduler.cancel,
+  });
+
+  win.emit("resize");
+  assert.equal(scheduler.pendingCount(), 1, "restore must be debounced");
+  assert.equal(refocusCalls, 0);
+  scheduler.runNext();
+  assert.equal(refocusCalls, 1);
+
+  detach();
+});
+
+test("a continuous frame drag only triggers one restore", () => {
+  const win = createWindowStub();
+  const scheduler = createScheduler();
+  let refocusCalls = 0;
+  const detach = attachWindowResizeFocusRestore({
+    win,
+    doc: { querySelector: () => null, hasFocus: () => true } as MinimalDocument,
+    refocus: () => { refocusCalls += 1; },
+    scheduleTimeout: scheduler.schedule,
+    cancelTimeout: scheduler.cancel,
+  });
+
+  win.emit("resize");
+  win.emit("resize");
+  win.emit("resize");
+  scheduler.runNext();
+  assert.equal(refocusCalls, 1, "debounced resizes must collapse into one restore");
+
+  detach();
+});
+
+test("resize does not steal focus when the app window is not focused", () => {
+  const win = createWindowStub();
+  const scheduler = createScheduler();
+  let refocusCalls = 0;
+  const detach = attachWindowResizeFocusRestore({
+    win,
+    doc: { querySelector: () => null, hasFocus: () => false } as MinimalDocument,
+    refocus: () => { refocusCalls += 1; },
+    scheduleTimeout: scheduler.schedule,
+    cancelTimeout: scheduler.cancel,
+  });
+
+  win.emit("resize");
+  scheduler.runNext();
+  assert.equal(refocusCalls, 0);
+
+  detach();
+});
+
+test("resize restore is skipped while a modal dialog is open", () => {
+  const win = createWindowStub();
+  const scheduler = createScheduler();
+  let refocusCalls = 0;
+  const detach = attachWindowResizeFocusRestore({
+    win,
+    doc: {
+      querySelector: (selector: string) => (
+        selector === '[role="dialog"][data-state="open"]' ? {} : null
+      ),
+      hasFocus: () => true,
+    } as MinimalDocument,
+    refocus: () => { refocusCalls += 1; },
+    scheduleTimeout: scheduler.schedule,
+    cancelTimeout: scheduler.cancel,
+  });
+
+  win.emit("resize");
+  scheduler.runNext();
+  assert.equal(refocusCalls, 0);
+
+  detach();
+});
+
+test("resize does not steal focus from an active editable field", () => {
+  const win = createWindowStub();
+  const scheduler = createScheduler();
+  let refocusCalls = 0;
+  const detach = attachWindowResizeFocusRestore({
+    win,
+    doc: {
+      querySelector: () => null,
+      hasFocus: () => true,
+      activeElement: { tagName: "INPUT", matches: () => false },
+    } as unknown as MinimalDocument,
+    refocus: () => { refocusCalls += 1; },
+    scheduleTimeout: scheduler.schedule,
+    cancelTimeout: scheduler.cancel,
+  });
+
+  win.emit("resize");
+  scheduler.runNext();
+  assert.equal(refocusCalls, 0, "restore must not yank focus out of an editable field");
+
+  detach();
+});
+
+test("resize does not steal focus from a contenteditable field", () => {
+  const win = createWindowStub();
+  const scheduler = createScheduler();
+  let refocusCalls = 0;
+  const detach = attachWindowResizeFocusRestore({
+    win,
+    doc: {
+      querySelector: () => null,
+      hasFocus: () => true,
+      activeElement: { tagName: "DIV", isContentEditable: true, matches: () => false },
+    } as unknown as MinimalDocument,
+    refocus: () => { refocusCalls += 1; },
+    scheduleTimeout: scheduler.schedule,
+    cancelTimeout: scheduler.cancel,
+  });
+
+  win.emit("resize");
+  scheduler.runNext();
+  assert.equal(refocusCalls, 0);
+
+  detach();
+});
+
+test("resize still restores while the xterm helper textarea is focused", () => {
+  const win = createWindowStub();
+  const scheduler = createScheduler();
+  let refocusCalls = 0;
+  const detach = attachWindowResizeFocusRestore({
+    win,
+    doc: {
+      querySelector: () => null,
+      hasFocus: () => true,
+      activeElement: {
+        tagName: "TEXTAREA",
+        matches: (selector: string) => selector === "textarea.xterm-helper-textarea",
+      },
+    } as unknown as MinimalDocument,
+    refocus: () => { refocusCalls += 1; },
+    scheduleTimeout: scheduler.schedule,
+    cancelTimeout: scheduler.cancel,
+  });
+
+  win.emit("resize");
+  scheduler.runNext();
+  assert.equal(refocusCalls, 1, "terminal-owned focus must be restored after resize");
+
+  detach();
+});
+
+test("detach removes the listener and cancels a pending restore", () => {
+  const win = createWindowStub();
+  const scheduler = createScheduler();
+  let refocusCalls = 0;
+  const detach = attachWindowResizeFocusRestore({
+    win,
+    doc: { querySelector: () => null, hasFocus: () => true } as MinimalDocument,
+    refocus: () => { refocusCalls += 1; },
+    scheduleTimeout: scheduler.schedule,
+    cancelTimeout: scheduler.cancel,
+  });
+
+  win.emit("resize");
+  detach();
+
+  assert.equal((win.listeners.get("resize") ?? []).length, 0, "listener must be removed");
+  assert.equal(scheduler.pendingCount(), 0, "pending restore must be cancelled");
+  scheduler.runNext();
+  assert.equal(refocusCalls, 0);
+});
+
+test("a win without listener support degrades to a no-op detach", () => {
+  const detach = attachWindowResizeFocusRestore({
+    win: null,
+    refocus: () => {},
+    scheduleTimeout: () => 1,
+    cancelTimeout: () => {},
+  });
+  assert.doesNotThrow(() => detach());
+});

components/terminal/restoreWindowResizeFocus.ts

@@ -0,0 +1,104 @@
+import { hasOpenAppDialog } from "./focusTerminalSession";
+
+/** Debounce so a continuous frame drag (or maximize transition) triggers one restore. */
+export const WINDOW_RESIZE_RESTORE_FOCUS_DELAY_MS = 120;
+
+export type MinimalWindow = {
+  addEventListener?: (type: string, listener: () => void) => unknown;
+  removeEventListener?: (type: string, listener: () => void) => unknown;
+};
+
+export type MinimalActiveElement = {
+  tagName?: string | null;
+  isContentEditable?: boolean;
+  matches?: (selector: string) => boolean;
+};
+
+export type MinimalDocument = Parameters<typeof hasOpenAppDialog>[0] & {
+  hasFocus?: () => boolean;
+  activeElement?: MinimalActiveElement | null;
+};
+
+/**
+ * True when keyboard focus sits in an editable app field (search box, chat
+ * input, SFTP filter, inline rename, ...) that is not an xterm helper
+ * textarea. Resize-driven restores must not yank focus away from such fields.
+ * Focus parked on `body`/`html` (or an xterm helper textarea) does not count
+ * as editing another field.
+ */
+export const hasActiveEditableElement = (doc: MinimalDocument | null): boolean => {
+  const element = doc?.activeElement;
+  if (!element) return false;
+  if (typeof element.matches === "function" && element.matches("textarea.xterm-helper-textarea")) {
+    return false;
+  }
+  const tagName = typeof element.tagName === "string" ? element.tagName.toLowerCase() : "";
+  return (
+    tagName === "input"
+    || tagName === "textarea"
+    || tagName === "select"
+    || Boolean(element.isContentEditable)
+  );
+};
+
+type AttachWindowResizeFocusRestoreOptions = {
+  win?: MinimalWindow | null;
+  doc?: MinimalDocument | null;
+  refocus?: () => void;
+  delayMs?: number;
+  scheduleTimeout?: (callback: () => void, delay: number) => unknown;
+  cancelTimeout?: (id: unknown) => void;
+};
+
+/**
+ * #3647: dragging the OS window frame (or maximizing) leaves the active xterm
+ * helper textarea unfocused, so keystrokes do nothing until the user clicks
+ * back into the terminal. Attach a window `resize` listener that re-runs the
+ * tab-change refocus path after the resize settles.
+ *
+ * Restore is skipped when the app window does not hold OS input focus, when a
+ * modal dialog is open, or when an editable element other than the xterm
+ * helper textarea already holds focus, so the restore never steals typing
+ * from elsewhere.
+ */
+export const attachWindowResizeFocusRestore = (
+  {
+    win = typeof window !== "undefined" ? window : null,
+    doc = typeof document !== "undefined" ? document : null,
+    refocus,
+    delayMs = WINDOW_RESIZE_RESTORE_FOCUS_DELAY_MS,
+    scheduleTimeout = (callback: () => void, delay: number) => setTimeout(callback, delay),
+    cancelTimeout = (id: unknown) => clearTimeout(id as ReturnType<typeof setTimeout>),
+  }: AttachWindowResizeFocusRestoreOptions = {},
+): (() => void) => {
+  if (!win?.addEventListener || !win.removeEventListener || typeof refocus !== "function") {
+    return () => {};
+  }
+
+  let timerId: unknown = null;
+  const restoreFocus = () => {
+    timerId = null;
+    if (doc?.hasFocus?.() === false) return;
+    if (hasOpenAppDialog(doc)) return;
+    // The window holds OS focus, but the user may still be typing in a
+    // non-terminal field (terminal search, AI chat, SFTP filter, rename).
+    // Never steal focus from an active editable element.
+    if (hasActiveEditableElement(doc)) return;
+    refocus();
+  };
+  const handleResize = () => {
+    if (timerId !== null) {
+      cancelTimeout(timerId);
+    }
+    timerId = scheduleTimeout(restoreFocus, delayMs);
+  };
+
+  win.addEventListener("resize", handleResize);
+  return () => {
+    win.removeEventListener("resize", handleResize);
+    if (timerId !== null) {
+      cancelTimeout(timerId);
+      timerId = null;
+    }
+  };
+};

components/terminal/runtime/createTerminalSessionStarters.localShellArgs.test.ts

@@ -0,0 +1,104 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import { createTerminalSessionStarters } from "./createTerminalSessionStarters";
+
+const noop = () => undefined;
+
+const makeCtx = (
+  host: Record<string, unknown>,
+  startLocalSession: (options: Record<string, unknown>) => Promise<string>,
+) => ({
+  host: {
+    id: "host-1",
+    label: "Local Shell",
+    hostname: "localhost",
+    username: "",
+    protocol: "local",
+    ...host,
+  },
+  keys: [],
+  identities: [],
+  resolvedChainHosts: [],
+  sessionId: "session-1",
+  terminalSettings: {},
+  terminalBackend: {
+    backendAvailable: () => true,
+    telnetAvailable: () => true,
+    moshAvailable: () => true,
+    etAvailable: () => true,
+    localAvailable: () => true,
+    serialAvailable: () => true,
+    execAvailable: () => true,
+    startSSHSession: async () => "ssh-session",
+    startLocalSession,
+    onSessionData: () => noop,
+    onSessionExit: () => noop,
+    writeToSession: noop,
+    resizeSession: noop,
+  },
+  sessionRef: { current: null },
+  hasConnectedRef: { current: true },
+  hasRunStartupCommandRef: { current: false },
+  disposeDataRef: { current: null },
+  disposeExitRef: { current: null },
+  fitAddonRef: { current: null },
+  serializeAddonRef: { current: null },
+  pendingAuthRef: { current: null },
+  updateStatus: noop,
+  setStatus: noop,
+  setError: noop,
+  setNeedsAuth: noop,
+  setAuthRetryMessage: noop,
+  setAuthPassword: noop,
+  setProgressLogs: noop,
+  setProgressValue: noop,
+  setChainProgress: noop,
+});
+
+const term = {
+  cols: 120,
+  rows: 32,
+  write: noop,
+  writeln: noop,
+  scrollToBottom: noop,
+};
+
+test("startLocal omits an empty no-args snapshot so backend defaults apply", async () => {
+  // Vault local hosts snapshot absent args as [] to keep launch-time no-args
+  // semantics for clone/popup relaunch, but the snapshot must not be passed to
+  // the bridge: an empty array is truthy and would suppress the bridge's
+  // discovered-shell args and getLocalShellArgs fallbacks (login flags,
+  // PowerShell -NoLogo).
+  let started: Record<string, unknown> | null = null;
+  const ctx = makeCtx(
+    { localShell: "fish", localShellArgs: [] },
+    async (options) => {
+      started = options;
+      return "local-session";
+    },
+  );
+
+  await createTerminalSessionStarters(ctx as never).startLocal(term as never);
+
+  assert.ok(started);
+  assert.equal((started as { shell?: string }).shell, "fish");
+  assert.equal((started as { shellArgs?: string[] }).shellArgs, undefined);
+});
+
+test("startLocal passes explicit local shell args through", async () => {
+  let started: Record<string, unknown> | null = null;
+  const ctx = makeCtx(
+    { localShell: "bash", localShellArgs: ["--login", "-i"] },
+    async (options) => {
+      started = options;
+      return "local-session";
+    },
+  );
+
+  await createTerminalSessionStarters(ctx as never).startLocal(term as never);
+
+  assert.ok(started);
+  assert.equal((started as { shell?: string }).shell, "bash");
+  assert.deepEqual((started as { shellArgs?: string[] }).shellArgs, ["--login", "-i"]);
+});

components/terminal/runtime/createTerminalSessionStarters.test.ts

@@ -3653,7 +3653,13 @@ test("restored local reconnect runs the host startup command while automatic ret
   assert.deepEqual(sessionWrites, []);
 });
 
-test("local session start uses per-session directory before global default", async () => {
+for (const { name, hostDirectory, globalDirectory, expectedDirectory } of [
+  { name: "uses saved directory before global default", hostDirectory: "/Users/alice/project", globalDirectory: "/Users/alice/default", expectedDirectory: "/Users/alice/project" },
+  { name: "inherits global directory when unset", hostDirectory: undefined, globalDirectory: "/Users/alice/default", expectedDirectory: "/Users/alice/default" },
+  { name: "inherits global directory when cleared", hostDirectory: "", globalDirectory: "/Users/alice/default", expectedDirectory: "/Users/alice/default" },
+  { name: "leaves directory unset for backend home default", hostDirectory: undefined, globalDirectory: undefined, expectedDirectory: undefined },
+]) {
+test(`local session start ${name}`, async () => {
   let capturedOptions: Record<string, unknown> | null = null;
   const terminalBackend = {
     backendAvailable: () => true,
@@ -3685,16 +3691,17 @@ test("local session start uses per-session directory before global default", asy
       hostname: "local",
       username: "",
       protocol: "local",
-      localStartDir: "/Users/alice/project",
+      localStartDir: hostDirectory,
     },
-    terminalSettings: { localStartDir: "/Users/alice/default" },
+    terminalSettings: { localStartDir: globalDirectory },
     terminalBackend,
   });
 
   await createTerminalSessionStarters(ctx as never).startLocal(createTermStub() as never);
 
-  assert.equal(capturedOptions?.cwd, "/Users/alice/project");
+  assert.equal(capturedOptions?.cwd, expectedDirectory);
 });
+}
 
 test("local session restores cwd before startup command after attaching", async () => {
   const sessionWrites: Array<{ id: string; data: string; automated?: boolean }> = [];

components/terminal/runtime/createTerminalSessionStarters.ts

@@ -1835,8 +1835,14 @@ export const createTerminalSessionStarters = (ctx: TerminalSessionStartersContex
       // which was already resolved to command+args and stored on the session object by App.tsx.
       // Only pass shell/shellArgs when we have concrete per-session values;
       // otherwise omit them so the backend uses its own default shell detection.
+      // An empty array is truthy, so `|| undefined` does not filter it out.
+      // Vault local hosts snapshot absent args as `[]` (to preserve
+      // launch-time no-args semantics for clone/popup relaunch), but the
+      // snapshot must still be omitted here: the bridge only applies its
+      // discovered-shell args and getLocalShellArgs fallbacks when shellArgs
+      // is absent (#1221).
       const sessionShell = ctx.host.localShell;
-      const sessionShellArgs = ctx.host.localShellArgs;
+      const sessionShellArgs = ctx.host.localShellArgs?.length ? ctx.host.localShellArgs : undefined;
       const localStartDir = ctx.host.localStartDir || ctx.terminalSettings?.localStartDir;
 
       const id = await ctx.terminalBackend.startLocalSession({
@@ -1844,7 +1850,7 @@ export const createTerminalSessionStarters = (ctx: TerminalSessionStartersContex
         cols: term.cols,
         rows: term.rows,
         shell: sessionShell || undefined,
-        shellArgs: sessionShellArgs || undefined,
+        shellArgs: sessionShellArgs,
         cwd: localStartDir,
         env: {
           TERM: ctx.terminalSettings?.terminalEmulationType ?? "xterm-256color",

components/terminal/runtime/cursorLineHighlight.test.ts

@@ -33,7 +33,7 @@ const createFakeTerm = (cols = 80) => {
     onRender: (handler: (element: FakeElement) => void) => { dispose: () => void };
     onDispose: (handler: Handler) => { dispose: () => void };
   }> = [];
-  const markers: Array<{ line: number; disposed: boolean }> = [];
+  const markers: Array<{ line: number; disposed: boolean; dispose: () => void }> = [];
 
   const term = {
     cols,
@@ -477,6 +477,84 @@ test('CursorLineHighlighter restores after the terminal resets its decorations',
   highlighter.dispose();
 });
 
+test('CursorLineHighlighter self-heals when xterm disposes its decorations without a write', () => {
+  const term = createFakeTerm(80);
+  const highlighter = new CursorLineHighlighter(term as never);
+  highlighter.setEnabled(true);
+  assert.equal(term.decorations.at(-1)?.disposed, false);
+
+  // xterm-side disposal (decoration service reset / term.reset): no cursor
+  // move and no write follow, only the next render frame.
+  term.resetDecorations();
+  assert.equal(term.decorations[0]?.disposed, true);
+
+  term.render();
+  assert.equal(term.decorations.at(-1)?.disposed, false);
+  assert.equal(term.decorations.at(-1)?.options.width, 80);
+  highlighter.dispose();
+});
+
+test('CursorLineHighlighter recreates after a buffer clear wipes markers and decorations', () => {
+  const term = createFakeTerm(80);
+  const highlighter = new CursorLineHighlighter(term as never);
+  highlighter.setEnabled(true);
+  assert.equal(term.markers.at(-1)?.disposed, false);
+
+  // term.clear() disposes every marker; decorations follow their markers.
+  for (const marker of term.markers) marker.dispose();
+  term.resetDecorations();
+  assert.equal(term.decorations.at(-1)?.disposed, true);
+
+  term.render();
+  assert.equal(term.decorations.at(-1)?.disposed, false);
+  assert.equal(term.markers.at(-1)?.line, 0);
+  highlighter.dispose();
+});
+
+test('CursorLineHighlighter does not duplicate decorations on redundant renders', () => {
+  const term = createFakeTerm(80);
+  const highlighter = new CursorLineHighlighter(term as never);
+  highlighter.setEnabled(true);
+  const aliveBefore = term.decorations.filter((decoration) => !decoration.disposed).length;
+
+  term.render();
+  term.render();
+  assert.equal(
+    term.decorations.filter((decoration) => !decoration.disposed).length,
+    aliveBefore,
+  );
+  highlighter.dispose();
+});
+
+test('CursorLineHighlighter does not churn markers when a fully colored row has no decorations', () => {
+  const cols = 8;
+  const term = createFakeTerm(cols);
+  // Every cell has an explicit ANSI background and the row is full, so both
+  // highlight ranges and the blank tail are legitimately empty.
+  term.setColoredBackgrounds(Array.from({ length: cols }, (_, column) => column));
+  const highlighter = new CursorLineHighlighter(term as never);
+  highlighter.setEnabled(true);
+
+  assert.equal(term.decorations.length, 0);
+  assert.equal(term.markers.length, 1);
+  const marker = term.markers[0];
+  assert.ok(marker);
+  assert.equal(marker.disposed, false);
+  assert.equal(marker.line, 0);
+  const aliveBefore = term.markers.filter((candidate) => !candidate.disposed).length;
+
+  term.render();
+  term.render();
+  term.render();
+
+  assert.equal(term.markers.length, 1);
+  assert.equal(term.markers.filter((candidate) => !candidate.disposed).length, aliveBefore);
+  assert.equal(marker.disposed, false);
+  assert.equal(marker.line, 0);
+  assert.equal(term.decorations.length, 0);
+  highlighter.dispose();
+});
+
 test('CursorLineHighlighter clears in the alternate buffer and restores in normal buffer', () => {
   const term = createFakeTerm(80);
   const highlighter = new CursorLineHighlighter(term as never);

components/terminal/runtime/cursorLineHighlight.ts

@@ -37,6 +37,8 @@ export class CursorLineHighlighter implements IDisposable {
   private activeColor: string | null = null;
   private activeRanges: HighlightRange[] = [];
   private activeTailRanges: HighlightRange[] = [];
+  /** False once any tracked decoration has been disposed out from under us. */
+  private decorationsAlive = false;
   private readonly disposables: IDisposable[] = [];
   private pendingRefresh = false;
   private disposed = false;
@@ -46,10 +48,16 @@ export class CursorLineHighlighter implements IDisposable {
       this.term.onCursorMove(() => this.markPendingRefresh()),
       this.term.onWriteParsed(() => this.markPendingRefresh()),
       this.term.onRender(() => {
-        if (this.pendingRefresh) {
-          this.pendingRefresh = false;
-          this.refresh();
-        }
+        const pending = this.pendingRefresh;
+        this.pendingRefresh = false;
+        if (this.disposed || !this.enabled) return;
+        // Writes and cursor moves defer to render, but xterm can also dispose
+        // or clear our decorations out from under us (term.clear/reset,
+        // decoration service resets, marker reindexing) without any further
+        // cursor move or write. Verify the tracked set on every render so the
+        // highlight can self-heal at the cursor line instead of staying
+        // anchored to stale bookkeeping (wrong/missing line).
+        if (pending || !this.isTrackingIntact()) this.refresh();
       }),
       this.term.onSelectionChange(() => this.refresh({ force: true })),
       this.term.onResize(() => this.refresh({ force: true })),
@@ -111,6 +119,7 @@ export class CursorLineHighlighter implements IDisposable {
       color === this.activeColor &&
       rangesEqual(ranges, this.activeRanges) &&
       rangesEqual(tailRanges, this.activeTailRanges) &&
+      this.decorationsAlive &&
       this.marker &&
       !this.marker.isDisposed &&
       this.marker.line === absoluteLine
@@ -160,13 +169,18 @@ export class CursorLineHighlighter implements IDisposable {
 
     this.marker = marker;
     this.decorations = decorations;
+    // An empty set is valid when the whole row already has ANSI backgrounds or
+    // inverse cells. Tracking stays intact so later frames do not churn markers.
+    this.decorationsAlive = true;
     this.decorationDisposeListeners = decorations.map((decoration) =>
       decoration.onDispose(() => {
         if (this.decorations.includes(decoration)) {
+          this.decorationsAlive = false;
           this.activeLine = null;
           this.activeCols = null;
           this.activeColor = null;
           this.activeRanges = [];
+          this.activeTailRanges = [];
         }
       }),
     );
@@ -244,6 +258,7 @@ export class CursorLineHighlighter implements IDisposable {
     this.marker = null;
     this.decorations = [];
     this.decorationDisposeListeners = [];
+    this.decorationsAlive = false;
     this.activeLine = null;
     this.activeCols = null;
     this.activeColor = null;
@@ -251,6 +266,19 @@ export class CursorLineHighlighter implements IDisposable {
     this.activeTailRanges = [];
   }
 
+  /**
+   * Cheap render-time check that the tracked marker and decorations are still
+   * owned by xterm. xterm disposes highlight decorations on buffer clears,
+   * resets, and marker reindexing without emitting cursor-move/write events,
+   * so a stale tracking state must be recreated before the next frame paints.
+   */
+  private isTrackingIntact(): boolean {
+    if (this.marker === null || this.marker.isDisposed) {
+      return this.marker === null && this.decorations.length === 0;
+    }
+    return this.decorationsAlive;
+  }
+
   private clearOwned(
     marker: IMarker | null,
     decorations: IDecoration[],

components/terminal/snippetCompleter.test.ts

@@ -111,3 +111,31 @@ test("matches Chinese labels by pinyin and initials (smart suggest)", () => {
   assert.equal(getSnippetSuggestions("bushu", [s], {})[0]?.snippet?.id, "zh");
   assert.equal(getSnippetSuggestions("bsfw", [s], {})[0]?.snippet?.id, "zh");
 });
+
+test("prefixOnly mode matches at word boundaries (argument position, #3622)", () => {
+  const s = snip({ id: "mail", label: "set-email", command: "git config user.email a@b.c" });
+  // First 3 letters of the label's last word still match while typing an
+  // argument, e.g. after `git pull `.
+  assert.equal(getSnippetSuggestions("ema", [s], { prefixOnly: true })[0]?.snippet?.id, "mail");
+  // Mid-word substrings do not match.
+  const gmail = snip({ id: "gm", label: "gmail", command: "echo gmail" });
+  assert.deepEqual(getSnippetSuggestions("mai", [gmail], { prefixOnly: true }), []);
+});
+
+test("prefixOnly mode matches Chinese labels via pinyin and initials", () => {
+  const s = snip({ id: "zh", label: "部署服务", command: "kubectl apply" });
+  assert.equal(getSnippetSuggestions("bush", [s], { prefixOnly: true })[0]?.snippet?.id, "zh");
+  const mailbox = snip({ id: "yx", label: "邮箱", command: "user@example.com" });
+  assert.equal(getSnippetSuggestions("yx", [mailbox], { prefixOnly: true })[0]?.snippet?.id, "yx");
+});
+
+test("prefixOnly mode does not match option-prefixed needles (#3623)", () => {
+  // The pinyin fallback must not strip the leading "--"/"-" punctuation:
+  // "--ve" (from `git --ve`) would otherwise match "version", and "-d"
+  // (from `git -d`) match "deploy" via a single typed letter, displacing
+  // the real Fig option completions while typing flags.
+  const version = snip({ id: "v", label: "version", command: "echo version" });
+  const deploy = snip({ id: "d", label: "deploy", command: "kubectl apply" });
+  assert.deepEqual(getSnippetSuggestions("--ve", [version], { prefixOnly: true }), []);
+  assert.deepEqual(getSnippetSuggestions("-d", [deploy], { prefixOnly: true }), []);
+});

components/terminal/terminalAutocompleteInput.test.ts

@@ -177,7 +177,7 @@ test("path history follows the current argument instead of the whole line", () =
   assert.equal(changedArgument.popupVisible, false);
 });
 
-test("provider-specific non-history rows remain until their debounced refresh", () => {
+test("snippet rows are removed synchronously while their next query is pending", () => {
   const snippet: CompletionSuggestion = {
     text: "deploy production",
     displayText: "deploy production",
@@ -186,7 +186,8 @@ test("provider-specific non-history rows remain until their debounced refresh",
   };
 
   const next = reconcileAutocompletePopupState(popupState([snippet]), "dp");
-  assert.deepEqual(next.suggestions, [snippet]);
+  assert.deepEqual(next.suggestions, []);
+  assert.equal(next.popupVisible, false);
   assert.equal(next.selectedIndex, -1);
 });
 

components/terminal/terminalAutocompleteKeyEvent.test.ts

@@ -1,6 +1,8 @@
 import test from "node:test";
 import assert from "node:assert/strict";
 
+import { reconcileAutocompletePopupState } from "./autocomplete/useTerminalAutocomplete.ts";
+import type { AutocompleteState } from "./autocomplete/useTerminalAutocomplete.ts";
 import { handleTerminalAutocompleteKeyEvent } from "./autocomplete/terminalAutocompleteKeyEvent.ts";
 
 const suggestion = (text: string) => ({
@@ -348,3 +350,32 @@ test("subdir Escape does not arm Meta prefix", () => {
   assert.equal(context.escMetaPrefixUntilRef.current, 0);
 });
 
+
+for (const edited of [false, true]) {
+  test(`snippet navigation before provider refresh: edited=${edited}`, () => {
+    let runs = 0;
+    const initial: AutocompleteState = {
+      suggestions: [{
+        text: "deploy", displayText: "deploy", source: "snippet", score: 2000,
+        snippet: { id: "deploy", label: "deploy", command: "echo deploy" },
+      }],
+      selectedIndex: -1, popupVisible: true,
+      popupAnchorViewport: { left: 0, top: 0, bottom: 0 },
+      expandUpward: false, subDirPanels: [], subDirFocusLevel: -1,
+    };
+    const stateRef = { current: edited ? reconcileAutocompletePopupState(initial, "git pull xyz") : initial };
+    const { context } = createContext({
+      stateRef,
+      setState(update: AutocompleteState | ((prev: AutocompleteState) => AutocompleteState)) {
+        stateRef.current = typeof update === "function" ? update(stateRef.current) : update;
+      },
+      acceptSnippet() { runs++; return true; },
+    });
+    // An unselected snippet does not execute on direct Enter.
+    handleTerminalAutocompleteKeyEvent(keyEvent("Enter"), context);
+    assert.equal(runs, 0);
+    handleTerminalAutocompleteKeyEvent(keyEvent("ArrowDown"), context);
+    handleTerminalAutocompleteKeyEvent(keyEvent("Enter"), context);
+    assert.equal(runs, edited ? 0 : 1);
+  });
+}

components/terminalLayer/TerminalLayerSupport.tsx

@@ -584,6 +584,7 @@ const AIChatPanelsHostInner: React.FC<AIChatPanelsHostProps> = ({
                     addDraftFiles={aiConfig.addDraftFiles}
                     removeDraftFile={aiConfig.removeDraftFile}
                     createSession={aiConfig.createSession}
+                    undoLastTurnInSession={aiConfig.undoLastTurnInSession}
                     deleteSession={aiConfig.deleteSession}
                     updateSessionTitle={aiConfig.updateSessionTitle}
                     updateSessionExternalSessionId={aiConfig.updateSessionExternalSessionId}
@@ -591,6 +592,7 @@ const AIChatPanelsHostInner: React.FC<AIChatPanelsHostProps> = ({
                     updateLastMessage={aiConfig.updateLastMessage}
                     updateMessageById={aiConfig.updateMessageById}
                     persistContextCompaction={aiConfig.persistContextCompaction}
+                    forkSessionFromMessage={aiConfig.forkSessionFromMessage}
                     providers={aiConfig.providers}
                     activeProviderId={aiConfig.activeProviderId}
                     activeModelId={aiConfig.activeModelId}

components/terminalLayer/useTerminalLayerEffects.ts

@@ -23,6 +23,7 @@ import {
   type SidePanelTabRemap,
 } from '../../domain/workspaceSidePanelTabRemap';
 import { AI_PANEL_FORCE_HIDE_SHELL } from '../ai/aiPanelDiagnostics';
+import { attachWindowResizeFocusRestore } from '../terminal/restoreWindowResizeFocus';
 import { toast } from '../ui/toast';
 import { getTerminalSidePanelShellWidth } from './TerminalLayerSidePanelSection';
 import type { RendererCwdSource } from '../terminal/sftpCwd';
@@ -747,6 +748,23 @@ export function useTerminalLayerEffects(ctx: TerminalLayerEffectsContext) {
     refocusActiveTerminalSession();
   }, [activeTabId, isTerminalLayerVisible, refocusActiveTerminalSession]);
 
+  // Restore keyboard focus after the OS window is resized or maximized.
+  // #3647: dragging the frame (or maximizing) leaves the active xterm helper
+  // textarea unfocused on Windows, so keystrokes do nothing until a click.
+  // Reuse the tab-change refocus path; the helper only fires once the resize
+  // settles and is gated on the app window actually holding input focus.
+  useEffect(() => {
+    if (!isTerminalLayerVisible) return undefined;
+    return attachWindowResizeFocusRestore({
+      win: window,
+      doc: document,
+      refocus: () => {
+        if (isComposeBarOpen) return;
+        refocusActiveTerminalSession?.();
+      },
+    });
+  }, [document, isComposeBarOpen, isTerminalLayerVisible, refocusActiveTerminalSession, window]);
+
   // When focusedSessionId changes or terminal layer becomes visible,
     // focus the corresponding terminal to restore :focus-within CSS state
     useEffect(() => {

components/top-tabs/TopTabItems.tsx

@@ -86,7 +86,7 @@ const SessionTabIcon: React.FC<{
   // Local protocol → shell-specific icon if available, else OS-specific icon
   if (protocol === 'local' || host?.protocol === 'local' || (!protocol && !host)) {
     // Use shell icon from discovery when available
-    const iconId = shellIcon || host?.localShellIcon;
+    const iconId = shellIcon ?? host?.localShellIcon;
     if (iconId) {
       return (
         <img