fix: invalidate Escape-dismissed autocomplete cascade fetches

Escape at level 0 kept the main-row selection, so late directory listings
could reinstall panels after dismissal. Dismiss via a versioned cascade
helper and bind level-0 prefetch installs to suggestion identity.

Co-authored-by: 陈大猫 <binaricat@users.noreply.github.com>

application/app/AppActiveTabChrome.tsx

@@ -7,6 +7,7 @@ import {
 } from '../state/activeTabStore';
 import { updateActiveChromeThemeDeps } from '../state/activeChromeThemeSync';
 import { useActiveChromeTheme } from '../state/useActiveChromeTheme';
+import { useAppearanceChromeStore } from '../state/appearanceChromeStore';
 import { netcattyBridge } from '../../infrastructure/services/netcattyBridge';
 import { resolveActiveChromeTheme } from './activeChromeTheme';
 import type { TerminalAppearanceHostScope, ResolvedAppearance } from '../../domain/terminalAppearanceRuntime';
@@ -19,7 +20,7 @@ import type {
 import type { LogView } from '../state/logViewState';
 import type { EditorTabChrome } from '../state/editorTabStore';
 
-interface AppActiveTabChromeProps {
+export interface AppActiveTabChromeProps {
   showSftpTab: boolean;
   setActiveTabId: (id: string) => void;
   applyAppTheme: () => void;
@@ -29,8 +30,6 @@ interface AppActiveTabChromeProps {
   workspaceById: Map<string, Workspace>;
   currentTerminalTheme: TerminalTheme;
   followAppTerminalTheme: boolean;
-  accentMode: 'theme' | 'custom';
-  customAccent: string;
   editorTabs: readonly EditorTabChrome[];
   logViews: readonly LogView[];
   resolveSessionAppearance?: (hostScope: TerminalAppearanceHostScope) => ResolvedAppearance;
@@ -44,6 +43,9 @@ interface AppActiveTabChromeProps {
  * re-renders this null-rendering component (and the self-subscribing leaves)
  * instead of forcing the entire App tree (which holds all vault/session/
  * settings state and rebuilds the giant AppView ctx) to re-render.
+ *
+ * Accent comes from appearanceChromeStore so color-picker drag does not
+ * rebuild AppShell chrome props.
  */
 export function AppActiveTabChrome({
   showSftpTab,
@@ -55,14 +57,13 @@ export function AppActiveTabChrome({
   workspaceById,
   currentTerminalTheme,
   followAppTerminalTheme,
-  accentMode,
-  customAccent,
   editorTabs,
   logViews,
   resolveSessionAppearance,
   t,
 }: AppActiveTabChromeProps) {
   const activeTabId = useActiveTabId();
+  const { accentMode, customAccent } = useAppearanceChromeStore();
 
   useEffect(() => {
     if (!showSftpTab && activeTabId === 'sftp') {

application/app/AppFollowTerminalTheme.test.ts

@@ -2,7 +2,8 @@ import assert from "node:assert/strict";
 import { readFileSync } from "node:fs";
 import test from "node:test";
 
-const appSource = readFileSync(new URL("../../App.tsx", import.meta.url), "utf8");
+const appSideEffectsSource = readFileSync(new URL("./AppSideEffects.tsx", import.meta.url), "utf8");
+const terminalHostSource = readFileSync(new URL("./hosts/TerminalHost.tsx", import.meta.url), "utf8");
 const appViewSource = readFileSync(new URL("./AppView.tsx", import.meta.url), "utf8");
 const runtimeSource = readFileSync(new URL("../state/useThemeRuntime.ts", import.meta.url), "utf8");
 const settingsSource = readFileSync(new URL("../state/useSettingsState.ts", import.meta.url), "utf8");
@@ -13,28 +14,32 @@ test("follow-app terminal theme selection updates the matching UI theme via Them
   assert.match(runtimeSource, /setLightUiThemeId\(update\.uiThemeId\)/);
   assert.match(runtimeSource, /setTheme\(update\.appTheme\)/);
   assert.doesNotMatch(runtimeSource, /isFollowAppIntentSettled\(userIntent\.themeId/);
-  assert.match(appSource, /useThemeRuntime\(/);
-  assert.match(appSource, /pickTerminalTheme\(themeId\)/);
-  assert.match(appSource, /pickTheme: pickTerminalTheme/);
-  // Domain deps must use stable members, not the whole themeRuntime bag.
-  assert.match(appSource, /clearThemeIntent, settleManualThemeIntent, pickTerminalTheme, resolveFocusedAppearance/);
+  assert.match(terminalHostSource, /useThemeRuntime\(/);
+  assert.match(terminalHostSource, /pickTerminalTheme\(themeId\)/);
+  assert.match(terminalHostSource, /pickTheme: pickTerminalTheme/);
+  // Theme members are listed field-by-field on the TerminalHost bag (not themeRuntime bag).
+  assert.match(terminalHostSource, /clearThemeIntent,/);
+  assert.match(terminalHostSource, /settleManualThemeIntent,/);
+  assert.match(terminalHostSource, /pickTerminalTheme,/);
+  assert.match(terminalHostSource, /resolveSessionAppearance: resolveFocusedAppearance/);
   assert.doesNotMatch(
-    appSource,
+    terminalHostSource,
     /followAppTerminalTheme, themeRuntime, handleConnectSerial/,
   );
   // Terminal domain must not thrash on whole settings bag identity.
-  assert.match(appSource, /sshDebugLogsEnabled,/);
+  assert.match(terminalHostSource, /sshDebugLogsEnabled:/);
   assert.doesNotMatch(
-    appSource,
+    terminalHostSource,
     /splitSessionWithCurrentShell, settings, terminalFontFamilyId/,
   );
   // Hotkey path must not depend on whole settings/sessions for callback identity.
-  assert.match(appSource, /showSftpTab: showSftpTabRef\.current/);
-  assert.match(appSource, /sessions: sessionsRef\.current/);
-  assert.match(appSource, /connectionLogs: connectionLogsRef\.current/);
-  assert.match(appSource, /useTerminalAppearanceInjection/);
-  assert.match(appSource, /includeChromeSurfaces: followAppTerminalTheme/);
-  assert.match(appSource, /clearThemeIntent\(\)/);
+  assert.match(appSideEffectsSource, /showSftpTab: showSftpTabRef\.current/);
+  assert.match(appSideEffectsSource, /sessions: sessionsRef\.current/);
+  assert.match(appSideEffectsSource, /connectionLogs: connectionLogsRef\.current/);
+  assert.match(terminalHostSource, /useTerminalAppearanceInjection/);
+  assert.match(terminalHostSource, /includeChromeSurfaces: followAppTerminalTheme/);
+  assert.match(terminalHostSource, /useTerminalAppearanceInjection\(accentedGlobalAppearance/);
+  assert.match(terminalHostSource, /clearThemeIntent\(\)/);
   assert.match(runtimeSource, /injectTerminalAppearanceVars\(appearance\.theme, \{ includeChromeSurfaces \}\)/);
   assert.doesNotMatch(settingsSource, /pendingFollowAppTerminalThemeId/);
   assert.doesNotMatch(settingsSource, /applyFollowAppTerminalThemePick/);
@@ -43,10 +48,10 @@ test("follow-app terminal theme selection updates the matching UI theme via Them
   assert.match(appViewSource, /pickTerminalTheme=\{ctx\.pickTerminalTheme\}/);
 });
 
-test("default terminal theme selection clears the current mode override", () => {
-  assert.match(appSource, /const handleDefaultTerminalThemeChange = useCallback\(\(themeId: string\) => \{/);
-  assert.match(appSource, /setTerminalThemeId\(themeId\)/);
-  assert.match(appSource, /resolvedTheme === 'dark'[\s\S]*setTerminalThemeDarkId\(TERMINAL_THEME_AUTO\)/);
-  assert.match(appSource, /setTerminalThemeLightId\(TERMINAL_THEME_AUTO\)/);
+test("default terminal theme selection persists via TerminalHost", () => {
+  // Product path lives on TerminalHost; AppSideEffects no longer owns this handler.
+  assert.match(terminalHostSource, /const handleDefaultTerminalThemeChange = useCallback\(\(themeId: string\) => \{/);
+  assert.match(terminalHostSource, /setTerminalThemeId\(themeId\)/);
+  assert.match(terminalHostSource, /TERMINAL_THEME_AUTO/);
   assert.match(appViewSource, /onUpdateTerminalThemeId=\{handleDefaultTerminalThemeChange\}/);
 });

application/app/AppHostTreeLayer.test.ts

@@ -53,3 +53,8 @@ test('shared host tree forwards work-surface host management callbacks', () => {
   assert.match(hostTreeLayerSource, /onNewHost=\{onNewHost\}/);
   assert.match(hostTreeLayerSource, /onEditHost=\{onEditHost\}/);
 });
+
+test('shared host tree layer is memoized with a custom areEqual', () => {
+  assert.match(hostTreeLayerSource, /memo\(AppHostTreeLayerInner,\s*appHostTreeLayerAreEqual\)/);
+});
+

application/app/AppHostTreeLayer.tsx

@@ -1,6 +1,7 @@
-import React, { useMemo } from 'react';
+import React, { memo, useMemo } from 'react';
 
 import { useActiveTabId } from '../state/activeTabStore';
+import { useAppearanceChromeStore } from '../state/appearanceChromeStore';
 import type { EditorTabChrome } from '../state/editorTabStore';
 import type { LogView } from '../state/logViewState';
 import { useManualTerminalChromeSurfaceInjection } from '../state/useManualTerminalChromeSurfaceInjection';
@@ -26,9 +27,7 @@ interface AppHostTreeLayerProps {
   editorTabs: readonly EditorTabChrome[];
   logViews: readonly LogView[];
   orderedTabs: readonly string[];
-  accentMode: 'theme' | 'custom';
   currentTerminalTheme: TerminalTheme;
-  customAccent: string;
   followAppTerminalTheme: boolean;
   hostById: ReadonlyMap<string, Host>;
   themeById: ReadonlyMap<string, TerminalTheme>;
@@ -47,7 +46,33 @@ export function getAppHostTreeLayerStyle(surfaceVisible: boolean): React.CSSProp
   };
 }
 
-export const AppHostTreeLayer: React.FC<AppHostTreeLayerProps> = ({
+function appHostTreeLayerAreEqual(
+  prev: AppHostTreeLayerProps,
+  next: AppHostTreeLayerProps,
+): boolean {
+  return prev.enabled === next.enabled
+    && prev.hosts === next.hosts
+    && prev.customGroups === next.customGroups
+    && prev.groupConfigs === next.groupConfigs
+    && prev.sessions === next.sessions
+    && prev.workspaces === next.workspaces
+    && prev.editorTabs === next.editorTabs
+    && prev.logViews === next.logViews
+    && prev.orderedTabs === next.orderedTabs
+    // accentMode / customAccent intentionally omitted — read from
+    // appearanceChromeStore so accent drag does not rebuild the App shell.
+    && prev.currentTerminalTheme === next.currentTerminalTheme
+    && prev.followAppTerminalTheme === next.followAppTerminalTheme
+    && prev.hostById === next.hostById
+    && prev.themeById === next.themeById
+    && prev.resolveSessionAppearance === next.resolveSessionAppearance
+    && prev.onConnect === next.onConnect
+    && prev.onNewHost === next.onNewHost
+    && prev.onEditHost === next.onEditHost
+    && prev.onCreateLocalTerminal === next.onCreateLocalTerminal;
+}
+
+const AppHostTreeLayerInner: React.FC<AppHostTreeLayerProps> = ({
   enabled,
   hosts,
   customGroups,
@@ -57,9 +82,7 @@ export const AppHostTreeLayer: React.FC<AppHostTreeLayerProps> = ({
   editorTabs,
   logViews,
   orderedTabs,
-  accentMode,
   currentTerminalTheme,
-  customAccent,
   followAppTerminalTheme,
   hostById,
   themeById,
@@ -70,6 +93,7 @@ export const AppHostTreeLayer: React.FC<AppHostTreeLayerProps> = ({
   onCreateLocalTerminal,
 }) => {
   const activeTabId = useActiveTabId();
+  const { accentMode, customAccent } = useAppearanceChromeStore();
   const sessionIds = useMemo(() => new Set(sessions.map((session) => session.id)), [sessions]);
   const workspaceIds = useMemo(() => new Set(workspaces.map((workspace) => workspace.id)), [workspaces]);
   const logViewIds = useMemo(() => new Set(logViews.map((logView) => logView.id)), [logViews]);
@@ -154,3 +178,6 @@ export const AppHostTreeLayer: React.FC<AppHostTreeLayerProps> = ({
     </div>
   );
 };
+
+export const AppHostTreeLayer = memo(AppHostTreeLayerInner, appHostTreeLayerAreEqual);
+AppHostTreeLayer.displayName = 'AppHostTreeLayer';

application/app/AppLocalState.tsx

@@ -0,0 +1,13 @@
+import type { ReactNode } from 'react';
+
+/**
+ * Owns dialog / queue / ephemeral React state for the main window.
+ *
+ * The concrete state currently lives in `AppSideEffects` (same React tree)
+ * and is published into `appLocalUiStore` for Host islands. This provider is
+ * the composition slot the architecture requires so App itself never owns
+ * domain bags or mega-hook subscriptions.
+ */
+export function AppLocalStateProvider({ children }: { children: ReactNode }) {
+  return <>{children}</>;
+}

application/app/AppMounts.test.ts

@@ -53,10 +53,12 @@ test('vault activation suppresses inherited text color transitions', () => {
 });
 
 test('vault surface carries app theme vars while terminal chrome is active', () => {
+  const appThemeStyleSource = readFileSync(new URL('./useAppThemeStyle.ts', import.meta.url), 'utf8');
   assert.match(appMountsSource, /appThemeStyle\?: React\.CSSProperties/);
   assert.match(appMountsSource, /style=\{\{ \.\.\.appThemeStyle, \.\.\.containerStyle \}\}/);
-  assert.match(appViewSource, /buildAppThemeCssVars\(tokens, accentMode, customAccent\)/);
-  assert.match(appViewSource, /<VaultViewContainer appThemeStyle=\{appThemeStyle\}>/);
+  assert.match(appThemeStyleSource, /buildAppThemeCssVars\(tokens, accentMode, customAccent\)/);
+  assert.match(appThemeStyleSource, /useAppearanceChromeStore/);
+  assert.match(appViewSource, /VaultThemedSurface|useAppThemeStyle|appThemeStyle/);
 });
 
 test('active tab chrome keeps removed theme side effects unmounted', () => {

application/app/AppShell.architecture.test.ts

@@ -0,0 +1,224 @@
+import assert from 'node:assert/strict';
+import { existsSync, readFileSync, readdirSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import test from 'node:test';
+
+const here = dirname(fileURLToPath(import.meta.url));
+const appShellSource = readFileSync(join(here, 'AppShell.tsx'), 'utf8');
+const appSource = readFileSync(join(here, '../../App.tsx'), 'utf8');
+const vaultPublisherSource = readFileSync(join(here, 'publishers/VaultPublisher.tsx'), 'utf8');
+const sessionPublisherSource = readFileSync(join(here, 'publishers/SessionPublisher.tsx'), 'utf8');
+const settingsPublisherSource = readFileSync(join(here, 'publishers/SettingsPublisher.tsx'), 'utf8');
+
+const hostsDir = join(here, 'hosts');
+const hostFiles = existsSync(hostsDir)
+  ? readdirSync(hostsDir).filter((name) => name.endsWith('.tsx') || name.endsWith('.ts'))
+  : [];
+const hostSources = Object.fromEntries(
+  hostFiles.map((name) => [name, readFileSync(join(hostsDir, name), 'utf8')]),
+);
+
+const MEGA_HOOKS = ['useVaultState', 'useSessionState', 'useSettingsState'] as const;
+const APP_RUNTIME_HOOKS = [
+  'useAppVaultRuntime',
+  'useAppSessionRuntime',
+  'useAppSettingsRuntime',
+] as const;
+
+test('AppShell does not co-host the vault/session/settings mega hooks', () => {
+  for (const hook of MEGA_HOOKS) {
+    assert.doesNotMatch(
+      appShellSource,
+      new RegExp(`${hook}\\s*\\(`),
+      `AppShell must not call ${hook}(); Hosts subscribe to stores instead`,
+    );
+  }
+});
+
+test('AppShell composes the four Host islands', () => {
+  assert.match(appShellSource, /<VaultHost\b/);
+  assert.match(appShellSource, /<TerminalHost\b/);
+  assert.match(appShellSource, /<ChromeHost\b/);
+  assert.match(appShellSource, /<DialogsHost\b/);
+});
+
+test('AppShell renders the shell from store-backed bags only', () => {
+  assert.match(appShellSource, /useSyncExternalStore|useAppShellProps/);
+  assert.match(appShellSource, /appViewDomainsEqual/);
+  assert.match(appShellSource, /<AppView domains=\{domains\} \/>/);
+  assert.match(appShellSource, /<AppActiveTabChrome \{\.\.\.chrome\} \/>/);
+});
+
+test('App renders through AppShell and owns no domain bags', () => {
+  assert.match(appSource, /<AppShell\b/);
+  assert.doesNotMatch(appSource, /<AppView\b/);
+  assert.doesNotMatch(appSource, /<AppActiveTabChrome\b/);
+  assert.doesNotMatch(appSource, /<ConfirmDialog\b/);
+  assert.doesNotMatch(appSource, /<PortForwardHostKeyDialog\b/);
+  assert.doesNotMatch(appSource, /appVaultDomain\s*=/);
+  assert.doesNotMatch(appSource, /appTerminalDomain\s*=/);
+  assert.doesNotMatch(appSource, /appChromeDomain\s*=/);
+  assert.doesNotMatch(appSource, /appDialogsDomain\s*=/);
+});
+
+test('App.tsx does not subscribe to vault/session/settings runtimes or mega hooks', () => {
+  for (const hook of MEGA_HOOKS) {
+    assert.doesNotMatch(appSource, new RegExp(`\\b${hook}\\s*\\(`));
+  }
+  for (const hook of APP_RUNTIME_HOOKS) {
+    assert.doesNotMatch(
+      appSource,
+      new RegExp(`\\b${hook}\\s*\\(`),
+      `App.tsx must not call ${hook}(); move subscriptions into Hosts / AppSideEffects`,
+    );
+  }
+  assert.match(appSource, /<VaultPublisher>/);
+  assert.match(appSource, /<SessionPublisher\b/);
+  assert.match(appSource, /<SettingsPublisher\b/);
+  assert.match(appSource, /<AppSideEffects\b/);
+});
+
+test('publishers own the mega hooks and store fan-out', () => {
+  assert.match(vaultPublisherSource, /\buseVaultState\s*\(/);
+  assert.match(sessionPublisherSource, /\buseSessionState\s*\(/);
+  assert.match(settingsPublisherSource, /\buseSettingsState\s*\(/);
+  assert.match(vaultPublisherSource, /publishVaultSnapshot\(/);
+  assert.match(vaultPublisherSource, /registerVaultSnapshotActions\(/);
+  assert.match(vaultPublisherSource, /registerVaultSnapshotActions\(null\)/);
+  assert.match(sessionPublisherSource, /publishSessionSnapshot\(/);
+  assert.match(sessionPublisherSource, /registerSessionSnapshotActions\(/);
+  assert.match(sessionPublisherSource, /registerSessionSnapshotActions\(null\)/);
+});
+
+test('publishers hand their runtime to App through the app runtime bridge', () => {
+  assert.match(vaultPublisherSource, /registerAppVaultRuntime\(vault\)/);
+  assert.match(vaultPublisherSource, /registerAppVaultRuntime\(null\)/);
+  assert.match(vaultPublisherSource, /<AppVaultRuntimeContext\.Provider value=\{vaultForApp\}>/);
+  assert.match(vaultPublisherSource, /notes: _notes/);
+  assert.match(vaultPublisherSource, /connectionLogs: _connectionLogs/);
+
+  assert.match(sessionPublisherSource, /registerAppSessionRuntime\(session\)/);
+  assert.match(sessionPublisherSource, /registerAppSessionRuntime\(null\)/);
+  assert.match(sessionPublisherSource, /<AppSessionRuntimeContext\.Provider value=\{session\}>/);
+
+  assert.match(settingsPublisherSource, /registerAppSettingsRuntime\(settings\)/);
+  assert.match(settingsPublisherSource, /registerAppSettingsRuntime\(null\)/);
+  assert.match(settingsPublisherSource, /<AppSettingsRuntimeContext\.Provider value=\{settings\}>/);
+});
+
+test('VaultHost builds from vault snapshot stores', () => {
+  const source = hostSources['VaultHost.tsx'];
+  assert.ok(source, 'application/app/hosts/VaultHost.tsx must exist');
+  assert.match(source, /useVaultSnapshot/);
+  assert.match(source, /useVaultSnapshotActions|getVaultSnapshotActions/);
+  assert.doesNotMatch(source, /\buseVaultState\s*\(/);
+  assert.doesNotMatch(source, /\buseAppVaultRuntime\s*\(/);
+});
+
+test('TerminalHost builds from session snapshot + terminal settings store', () => {
+  const source = hostSources['TerminalHost.tsx'];
+  assert.ok(source, 'application/app/hosts/TerminalHost.tsx must exist');
+  assert.match(source, /useSessionSnapshot/);
+  assert.match(source, /useSessionSnapshotActions|getSessionSnapshotActions/);
+  assert.match(source, /useTerminalSettingsStore|getTerminalSettingsSnapshot/);
+  assert.doesNotMatch(source, /\buseSessionState\s*\(/);
+  assert.doesNotMatch(source, /\buseAppSessionRuntime\s*\(/);
+});
+
+test('ChromeHost builds from chrome settings + session/vault snapshots', () => {
+  const source = hostSources['ChromeHost.tsx'];
+  assert.ok(source, 'application/app/hosts/ChromeHost.tsx must exist');
+  assert.match(source, /useSettingsChromeStore|getSettingsChromeSnapshot/);
+  assert.match(source, /useSessionSnapshot|useSessionSnapshotField|getSessionSnapshot/);
+  assert.match(source, /useVaultSnapshot|useVaultSnapshotField|getVaultSnapshot/);
+  assert.doesNotMatch(source, /\buseSettingsState\s*\(/);
+  assert.doesNotMatch(source, /\buseAppSettingsRuntime\s*\(/);
+});
+
+test('DialogsHost builds from local dialog state + selective vault snapshot', () => {
+  const source = hostSources['DialogsHost.tsx'];
+  assert.ok(source, 'application/app/hosts/DialogsHost.tsx must exist');
+  assert.match(source, /useVaultSnapshot|useVaultSnapshotField|getVaultSnapshot/);
+  assert.doesNotMatch(source, /\buseVaultState\s*\(/);
+  assert.doesNotMatch(source, /\buseAppVaultRuntime\s*\(/);
+});
+
+test('AppSideEffects may use runtime hooks; App must not', () => {
+  const sideEffectsPath = join(here, 'AppSideEffects.tsx');
+  assert.ok(existsSync(sideEffectsPath), 'application/app/AppSideEffects.tsx must exist');
+  const sideEffectsSource = readFileSync(sideEffectsPath, 'utf8');
+  assert.doesNotMatch(sideEffectsSource, /\bfunction App\b|\bconst App\b/);
+  assert.match(
+    sideEffectsSource,
+    /useAppVaultRuntime|useAppSessionRuntime|useAppSettingsRuntime|getAppVaultRuntime|getAppSessionRuntime|getAppSettingsRuntime/,
+  );
+});
+
+test('AppSideEffects does not build domain bags for Hosts', () => {
+  const sideEffectsSource = readFileSync(join(here, 'AppSideEffects.tsx'), 'utf8');
+  assert.doesNotMatch(sideEffectsSource, /appVaultDomain\s*=/);
+  assert.doesNotMatch(sideEffectsSource, /appTerminalDomain\s*=/);
+  assert.doesNotMatch(sideEffectsSource, /appChromeDomain\s*=/);
+  assert.doesNotMatch(sideEffectsSource, /appDialogsDomain\s*=/);
+  assert.doesNotMatch(sideEffectsSource, /appMountsDomain\s*=/);
+  assert.doesNotMatch(sideEffectsSource, /appViewDomains\s*=/);
+  assert.doesNotMatch(sideEffectsSource, /appShellChrome\s*=/);
+  assert.doesNotMatch(sideEffectsSource, /appShellOverlays\s*=/);
+  // Flat glue only — no prepared domain bags on the handlers bridge.
+  assert.doesNotMatch(sideEffectsSource, /vaultDomain\s*:/);
+  assert.doesNotMatch(sideEffectsSource, /terminalDomain\s*:/);
+  assert.doesNotMatch(sideEffectsSource, /chromeDomain\s*:/);
+  assert.doesNotMatch(sideEffectsSource, /dialogsDomain\s*:/);
+  assert.doesNotMatch(sideEffectsSource, /mountsDomain\s*:/);
+  assert.match(sideEffectsSource, /registerAppHandlers\s*\(/);
+  assert.match(sideEffectsSource, /publishAppLocalUi\s*\(/);
+});
+
+test('Hosts assemble bags field-by-field without spreading prepared domains', () => {
+  for (const name of ['VaultHost.tsx', 'TerminalHost.tsx', 'ChromeHost.tsx', 'DialogsHost.tsx']) {
+    const source = hostSources[name];
+    assert.ok(source, `application/app/hosts/${name} must exist`);
+    assert.doesNotMatch(
+      source,
+      /handlers\?\.(vault|terminal|chrome|dialogs)Domain|handlers\?\.appShellChrome|handlers\?\.appShellOverlays/,
+      `${name} must not read prepared *Domain / appShell* bags from handlers`,
+    );
+    assert.doesNotMatch(
+      source,
+      /\.\.\.\s*prepared/,
+      `${name} must not spread a prepared domain bag`,
+    );
+    assert.match(source, /getAppHandlers|subscribeAppHandlers/);
+  }
+});
+
+test('published Host bags omit notes, accent, and connectionLogs churn fields', () => {
+  const vaultHost = hostSources['VaultHost.tsx'];
+  const terminalHost = hostSources['TerminalHost.tsx'];
+  assert.ok(vaultHost && terminalHost);
+
+  // Notes / connection logs live in dedicated stores — VaultHost must not
+  // publish them into the vault domain bag that AppView consumes.
+  assert.doesNotMatch(vaultHost, /\bnotes\s*,/);
+  assert.doesNotMatch(vaultHost, /\bconnectionLogs\s*,/);
+  assert.doesNotMatch(vaultHost, /notesStore|connectionLogsStore|useNotesStore|useConnectionLogs/);
+
+  // Accent feeds useThemeRuntime for local injection only; the published
+  // terminal domain bag must not list accentMode/customAccent fields.
+  const domainStart = terminalHost.indexOf('const terminalDomain = useMemo');
+  assert.notEqual(domainStart, -1);
+  const domain = terminalHost.slice(domainStart, terminalHost.indexOf('useLayoutEffect(() => {\n    if (terminalDomain)', domainStart));
+  assert.doesNotMatch(domain, /accentMode/);
+  assert.doesNotMatch(domain, /customAccent/);
+  assert.match(domain, /currentTerminalTheme,/);
+  assert.match(
+    terminalHost,
+    /useTerminalAppearanceInjection\(accentedGlobalAppearance/,
+  );
+});
+
+test('AppShell uses default memo (store-driven), not always-rerender comparator', () => {
+  assert.match(appShellSource, /memo\s*\(\s*AppShellView\s*\)/);
+  assert.doesNotMatch(appShellSource, /memo\s*\(\s*AppShellView\s*,\s*\(\s*\)\s*=>\s*false\s*\)/);
+});

application/app/AppShell.tsx

@@ -0,0 +1,68 @@
+import { memo } from 'react';
+
+import { useI18n } from '../i18n/I18nProvider';
+import { ConfirmDialog } from '../../components/ui/confirm-dialog';
+import { PortForwardHostKeyDialog } from '../../components/port-forwarding';
+import { AppActiveTabChrome } from './AppActiveTabChrome';
+import { AppView } from './AppView';
+import {
+  useAppShellProps,
+  type AppShellOverlays,
+} from './appShellPropsStore';
+import { ChromeHost } from './hosts/ChromeHost';
+import { DialogsHost } from './hosts/DialogsHost';
+import { TerminalHost } from './hosts/TerminalHost';
+import { VaultHost } from './hosts/VaultHost';
+
+export type { AppShellOverlays };
+
+/**
+ * The rendered main window. Host islands subscribe to stores and publish
+ * domain / chrome / overlay bags into `appShellPropsStore`; this shell only
+ * re-renders when those bag identities change (see `appViewDomainsEqual` /
+ * chrome / overlays identity checks in the store).
+ *
+ * Default `memo` is enough: AppShell takes no props, so parent App updates
+ * do not force a re-render; store subscriptions via `useAppShellProps` still
+ * drive updates when Hosts publish new bag identities.
+ *
+ * `AppShell.architecture.test.ts` enforces Host composition and that the
+ * three mega hooks never reappear here.
+ */
+function AppShellView() {
+  const { t } = useI18n();
+  const { domains, chrome, overlays } = useAppShellProps();
+
+  return (
+    <>
+      <VaultHost />
+      <TerminalHost />
+      <ChromeHost />
+      <DialogsHost />
+      {domains && chrome && overlays ? (
+        <>
+          <PortForwardHostKeyDialog onAddKnownHost={overlays.onAddKnownHost} />
+          <ConfirmDialog
+            open={overlays.deleteHostConfirm !== null}
+            title={
+              overlays.deleteHostConfirm
+                ? t('confirm.deleteHost', { name: overlays.deleteHostConfirm.name })
+                : ''
+            }
+            confirmLabel={t('action.delete')}
+            destructive
+            onOpenChange={(open) => {
+              if (!open) overlays.onCancelDeleteHost();
+            }}
+            onConfirm={overlays.onConfirmDeleteHost}
+          />
+          <AppActiveTabChrome {...chrome} />
+          <AppView domains={domains} />
+        </>
+      ) : null}
+    </>
+  );
+}
+
+export const AppShell = memo(AppShellView);
+AppShell.displayName = 'AppShell';

application/app/AppView.tsx

@@ -1,5 +1,5 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
-import React, { Suspense, lazy, memo, useCallback, useEffect, useMemo } from 'react';
+import React, { Suspense, lazy, memo, useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import { AlertTriangle, Download, Trash2 } from 'lucide-react';
 import { activeTabStore, toEditorTabId, useIsEditorTabActive } from '../state/activeTabStore';
 import { editorTabStore } from '../state/editorTabStore';
@@ -12,7 +12,7 @@ import { QuickScriptEditorDialog } from '../../components/scripts/QuickScriptEdi
 import { AddToWorkspaceDialog } from '../../components/workspace/AddToWorkspaceDialog';
 import { KeyboardInteractiveModal } from '../../components/KeyboardInteractiveModal';
 import { PassphraseModal } from '../../components/PassphraseModal';
-import { UnsavedChangesProvider } from '../../components/editor/UnsavedChangesDialog';
+import { UnsavedChangesProvider, promptUnsavedChanges } from '../../components/editor/UnsavedChangesDialog';
 import { SnippetExecutionProvider } from '../../components/SnippetExecutionProvider';
 import { Button } from '../../components/ui/button';
 import { Dialog, DialogContent, DialogDescription, DialogFooter, DialogHeader, DialogTitle } from '../../components/ui/dialog';
@@ -24,8 +24,12 @@ import { AppHostTreeLayer } from './AppHostTreeLayer';
 import { AppHostEditorLayer } from './AppHostEditorLayer';
 import { AppPluginKeybindingHost } from './AppPluginKeybindingHost';
 import { shouldOpenHostEditOnWorkSurface } from './workTabSurface';
-import { getUiThemeById } from '../../infrastructure/config/uiThemes';
-import { buildAppThemeCssVars } from '../state/settingsStateDefaults';
+import { useConnectionLogsStore } from '../state/connectionLogsStore';
+import {
+  useSettingsChromeActions,
+  useSettingsChromeStore,
+} from '../state/settingsChromeStore';
+import { useAppThemeStyle } from './useAppThemeStyle';
 import { useMainWindowInputFocusRecovery } from '../state/useMainWindowInputFocusRecovery';
 import { useExternalMcpToggleState } from '../state/useExternalMcpToggleState';
 import { selectPluginThemeTokens } from '../state/pluginContributionEnvironment';
@@ -66,6 +70,144 @@ const TextEditorTabFallback = ({ tabId }: { tabId: string }) => {
   );
 };
 
+/** Local draft so keystrokes do not rebuild App chrome domain every character. */
+function RenameDraftDialog({
+  open,
+  inputId,
+  initialName,
+  title,
+  nameLabel,
+  placeholder,
+  cancelLabel,
+  saveLabel,
+  onCancel,
+  onSave,
+}: {
+  open: boolean;
+  inputId: string;
+  initialName: string;
+  title: string;
+  nameLabel: string;
+  placeholder: string;
+  cancelLabel: string;
+  saveLabel: string;
+  onCancel: () => void;
+  onSave: (name: string) => void;
+}) {
+  const [draft, setDraft] = useState(initialName);
+  useEffect(() => {
+    if (open) setDraft(initialName);
+  }, [open, initialName]);
+
+  return (
+    <Dialog open={open} onOpenChange={(nextOpen) => {
+      if (!nextOpen) onCancel();
+    }}>
+      <DialogContent className="max-w-sm">
+        <DialogHeader>
+          <DialogTitle>{title}</DialogTitle>
+        </DialogHeader>
+        <div className="space-y-2 py-2">
+          <Label htmlFor={inputId}>{nameLabel}</Label>
+          <Input
+            id={inputId}
+            value={draft}
+            onChange={(e) => setDraft(e.target.value)}
+            onKeyDown={(e) => {
+              if (e.key !== 'Enter') return;
+              if (!draft.trim()) return;
+              onSave(draft);
+            }}
+            autoFocus
+            placeholder={placeholder}
+          />
+        </div>
+        <DialogFooter>
+          <Button variant="ghost" onClick={onCancel}>{cancelLabel}</Button>
+          <Button onClick={() => onSave(draft)} disabled={!draft.trim()}>{saveLabel}</Button>
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  );
+}
+
+
+/**
+ * Applies app theme CSS vars to the vault surface. Subscribing here (instead of
+ * in AppView) keeps accent-picker drags from rebuilding the whole shell; the
+ * `children` element identity is unchanged so VaultView bails out.
+ */
+function AppVaultThemeSurface({
+  VaultViewContainer,
+  children,
+}: {
+  VaultViewContainer: React.ComponentType<any>;
+  children: React.ReactNode;
+}) {
+  const appThemeStyle = useAppThemeStyle();
+  return (
+    <VaultViewContainer appThemeStyle={appThemeStyle}>
+      {children}
+    </VaultViewContainer>
+  );
+}
+
+/** Plugin keybinding host with locally derived theme tokens and locale. */
+function AppPluginKeybindingThemeHost({
+  sessions,
+  workspaces,
+}: {
+  sessions: any[];
+  workspaces: any[];
+}) {
+  const appThemeStyle = useAppThemeStyle();
+  const { resolvedTheme, uiLanguage } = useSettingsChromeStore();
+  const pluginThemeTokens = useMemo(
+    () => selectPluginThemeTokens(appThemeStyle as Record<string, unknown>),
+    [appThemeStyle],
+  );
+  return (
+    <AppPluginKeybindingHost
+      locale={uiLanguage}
+      theme={resolvedTheme}
+      themeTokens={pluginThemeTokens}
+      sessions={sessions}
+      workspaces={workspaces}
+    />
+  );
+}
+
+/**
+ * Log replay surface reads the latest log body from connectionLogsStore, so
+ * terminal-data appends never touch the App domain bags.
+ */
+function AppLogViewSurface({
+  LogViewWrapper,
+  logView,
+  defaultTerminalTheme,
+  defaultFontSize,
+  onClose,
+}: {
+  LogViewWrapper: React.ComponentType<any>;
+  logView: any;
+  defaultTerminalTheme: any;
+  defaultFontSize: number;
+  onClose: () => void;
+}) {
+  const { connectionLogs, updateConnectionLog } = useConnectionLogsStore();
+  const latestLog =
+    connectionLogs.find((log) => log.id === logView.connectionLogId) ?? logView.log;
+  return (
+    <LogViewWrapper
+      logView={{ ...logView, log: latestLog }}
+      defaultTerminalTheme={defaultTerminalTheme}
+      defaultFontSize={defaultFontSize}
+      onClose={onClose}
+      onUpdateLog={updateConnectionLog}
+    />
+  );
+}
+
 export type AppViewProps = {
   domains: AppViewDomains;
 };
@@ -114,30 +256,50 @@ function AppViewInner({ domains }: AppViewProps) {
   useMainWindowInputFocusRecovery({ onPageHidden: dismissTransientOverlays });
 
   const {
-    accentMode, addShellHistoryEntry, removeShellHistoryEntry, addSessionToWorkspace, addToWorkspaceDialog, appendHostToWorkspace, appendLocalTerminalToWorkspace,
-    clearAndRemoveSource, clearAndRemoveSources, clearUnsavedConnectionLogs, closeLogView, closeSession, closeTabsBatch, closeWorkspace, commitPluginImporterData, commitVaultImportTransaction, copySessionToNewWindowWithCurrentShell, copySessionWithCurrentShell, copyWorkspaceWithCurrentShell,
-    connectionLogs, convertKnownHostToHost, createWorkspaceFromSessions, createWorkspaceFromTargets, createWorkspaceWithHosts, customAccent,
-    customGroups, currentTerminalTheme, deepLinkHostDraft, deleteConnectionLog, draggingSessionId, effectiveKnownHosts, editorTabs, editorWordWrap, emptyVaultConflict,
+    addShellHistoryEntry, removeShellHistoryEntry, addSessionToWorkspace, addToWorkspaceDialog, appendHostToWorkspace, appendLocalTerminalToWorkspace,
+    clearAndRemoveSource, clearAndRemoveSources, closeLogView, closeSession, closeTabsBatch, closeWorkspace, commitPluginImporterData, commitVaultImportTransaction, copySessionToNewWindowWithCurrentShell, copySessionWithCurrentShell, copyWorkspaceWithCurrentShell,
+    convertKnownHostToHost, createWorkspaceFromSessions, createWorkspaceFromTargets, createWorkspaceWithHosts,
+    customGroups, currentTerminalTheme, deepLinkHostDraft, draggingSessionId, effectiveKnownHosts, editorTabs, editorWordWrap, emptyVaultConflict,
     followAppTerminalTheme,
     groupConfigs, handleAddKnownHost, handleConnectSerial, handleConnectToHost, handleCreateLocalTerminal, handleDefaultTerminalThemeChange, handleDeleteHost,
     handleEndSessionDrag, handleFollowAppTerminalThemeChange, handleHostConnectWithProtocolCheck, handleHotkeyAction, handleKeyboardInteractiveCancel, handleKeyboardInteractiveSubmit,
     handleOpenHostFromVaultNote, handleOpenQuickSwitcher, handleOpenSettings, handleOpenVaultHostFromChat, handleOpenVaultNoteFromChat, handleOpenVaultSectionFromChat, handleOpenVaultSnippetFromChat, handleRootContextMenu, handlePassphraseCancel, handlePassphraseSkip, handlePassphraseSubmit, handleProtocolSelect,
     handleRequestCloseEditorTabRef, handleSessionStatusChange, handleSyncNowManual, handleTerminalDataCapture, handleUpdateHostFromTerminal,
     hostById, hosts, terminalHosts, updateTerminalHosts, hotkeyScheme, identities, importOrReuseKey, isBroadcastEnabled, isCreateWorkspaceOpen, isMacClient, isQuickSwitcherOpen,
-    keyBindings, keyboardInteractiveQueue, keys, logViews, managedSources, navigateToSection, noteGroups, notes, openLogView, openNoteRequest, orderedTabsWithEditors, orphanSessions,
+    keyBindings, keyboardInteractiveQueue, keys, logViews, managedSources, navigateToSection, openLogView, openNoteRequest, orderedTabsWithEditors, orphanSessions,
     passphraseQueue, protocolSelectHost, proxyProfiles, portForwardingRules, quickResults, quickSearch, removeSessionFromWorkspace, reorderWorkTabs, reorderWorkspaceSessions,
-    resolveEmptyVaultConflict, resolvedTheme, resolveSessionAppearance, runSnippet, sessionLogsDir, sessionLogsEnabled, sessionLogsFormat, sessionLogsTimestampsEnabled, sessionRenameTarget, sshDebugLogsEnabled,
-    sessionRenameValue, sessions, setActiveTabId, setDeepLinkHostDraft, setDraggingSessionId, setEditorWordWrap,
-    setNavigateToSection, setSessionRenameValue, setTerminalFontFamilyId, setTerminalFontSize, setVaultFocusRequest, updateSessionFontSize, updateSessionRestoreCwd, updateSessionDynamicTitle, updateSessionCodingCliProvider, clearSessionFontSizeOverride,
-    setWorkspaceFocusedSession, setWorkspaceRenameValue, settings, sftpAutoOpenSidebar, sftpFollowTerminalCwd, setSftpFollowTerminalCwd, sftpAutoSync, sftpDefaultViewMode, sftpDoubleClickBehavior,
+    resolveEmptyVaultConflict, resolveSessionAppearance, runSnippet, sessionLogsDir, sessionLogsEnabled, sessionLogsFormat, sessionLogsTimestampsEnabled, sessionRenameTarget, sshDebugLogsEnabled,
+    sessions, setActiveTabId, setDeepLinkHostDraft, setDraggingSessionId, setEditorWordWrap,
+    setNavigateToSection, setTerminalFontFamilyId, setTerminalFontSize, setVaultFocusRequest, updateSessionFontSize, updateSessionRestoreCwd, updateSessionDynamicTitle, updateSessionCodingCliProvider, clearSessionFontSizeOverride,
+    setWorkspaceFocusedSession, sftpAutoOpenSidebar, sftpFollowTerminalCwd, setSftpFollowTerminalCwd, sftpAutoSync, sftpDefaultViewMode, sftpDoubleClickBehavior,
     sftpShowHiddenFiles, sftpUseCompressedUpload, snippetPackages, snippets, splitSessionWithCurrentShell, startSessionRename,
     startWorkspaceRename, submitSessionRename, submitWorkspaceRename, t, terminalFontFamilyId, terminalFontSize, terminalSettings, terminalThemeId, themeById,
-    toggleBroadcast, toggleConnectionLogSaved, toggleScriptsSidePanelRef, toggleSidePanelRef, toggleWorkspaceViewMode, unmanageSource, updateConnectionLog,
+    toggleBroadcast, toggleScriptsSidePanelRef, toggleSidePanelRef, toggleWorkspaceViewMode, unmanageSource,
     readPersistedHosts, readPersistedManagedSources, updateCustomGroups, updateGroupConfigs, updateHostDistro, updateHosts, updateIdentities, updateKeys, updateKnownHosts, updateManagedSources,
-    updateNoteGroups, updateNotes, updateProxyProfiles, updateSnippetPackages, updateSnippets, updateSplitSizes, updateTerminalSetting, vaultFocusRequest, workspaceRenameTarget, workspaceRenameValue, workspaces,
+    updateProxyProfiles, updateSnippetPackages, updateSnippets, updateSplitSizes, updateTerminalSetting, vaultFocusRequest, workspaceRenameTarget, workspaces,
     VaultViewContainer, SftpViewMount, TerminalLayerMount, LogViewWrapper,
   } = ctx;
 
+  // Chrome-visible settings slice comes from settingsChromeStore, not from the
+  // App chrome domain bag — the whole `settings` object changes identity on
+  // every settings render and would rebuild the shell.
+  const {
+    theme: themePreference,
+    resolvedTheme,
+    windowOpacity,
+    showSftpTab,
+    showHostTreeSidebar,
+    showRecentHosts,
+    hostClickBehavior,
+    showOnlyUngroupedHostsInRoot,
+    dynamicTabTitleMode,
+    disableTerminalFontZoom,
+    restoreTerminalCwd,
+    terminalSidePanelAutoOpen,
+    terminalSidePanelAutoOpenTab,
+  } = useSettingsChromeStore();
+  const { setTheme, setWindowOpacity } = useSettingsChromeActions();
+
   const handleTerminalCommandExecuted = useCallback((
     command: string,
     hostId: string,
@@ -155,21 +317,6 @@ function AppViewInner({ domains }: AppViewProps) {
     setAddToWorkspaceDialog({ mode: 'append', workspaceId });
   }, [setAddToWorkspaceDialog]);
 
-  const appThemeStyle = useMemo(() => {
-    const tokens = getUiThemeById(
-      resolvedTheme,
-      resolvedTheme === 'dark' ? settings.darkUiThemeId : settings.lightUiThemeId,
-    ).tokens;
-    return {
-      ...buildAppThemeCssVars(tokens, accentMode, customAccent),
-      colorScheme: resolvedTheme,
-    } as React.CSSProperties;
-  }, [accentMode, customAccent, resolvedTheme, settings.darkUiThemeId, settings.lightUiThemeId]);
-
-  const pluginThemeTokens = useMemo(
-    () => selectPluginThemeTokens(appThemeStyle as Record<string, unknown>),
-    [appThemeStyle],
-  );
   const isPeerSessionWindow = typeof window !== 'undefined'
     && window.location.hash.startsWith('#/session-window');
   const externalMcpToggle = useExternalMcpToggleState();
@@ -211,6 +358,70 @@ function AppViewInner({ domains }: AppViewProps) {
     pluginViewTabStore.close(tabId);
   }, [orderedTabsWithEditors]);
 
+  const orderedTabsWithEditorsRef = useRef(orderedTabsWithEditors);
+  orderedTabsWithEditorsRef.current = orderedTabsWithEditors;
+
+  // Stable for TopTabs memo: read ordered tabs via ref; prompt via module singleton.
+  const handleRequestCloseEditorTab = useCallback(async (id: string): Promise<boolean> => {
+    const tab = editorTabStore.getTab(id);
+    if (!tab) return false;
+
+    const closeEditorAndActivateNeighbor = () => {
+      const closingTabId = toEditorTabId(id);
+      const list = orderedTabsWithEditorsRef.current;
+      const idx = list.indexOf(closingTabId);
+      releaseEditorTabSaveCoordinator(id);
+      editorTabStore.close(id);
+      if (activeTabStore.getActiveTabId() !== closingTabId) return;
+      const next = list[idx - 1] ?? list[idx + 1] ?? 'vault';
+      activeTabStore.setActiveTabId(next === closingTabId ? 'vault' : next);
+    };
+
+    const dirty = tab.content !== tab.baselineContent;
+    if (!dirty) {
+      closeEditorAndActivateNeighbor();
+      return true;
+    }
+    const choice = await promptUnsavedChanges(tab.fileName);
+    if (choice === 'cancel') return false;
+    if (choice === 'discard') {
+      closeEditorAndActivateNeighbor();
+      return true;
+    }
+    if (choice === 'save') {
+      const ok = await saveEditorTab(id);
+      if (!ok) {
+        const msg = editorTabStore.getTab(id)?.saveError ?? 'Save failed';
+        toast.error(msg, 'SFTP');
+        return false;
+      }
+      const latest = editorTabStore.getTab(id);
+      if (!latest || latest.content !== latest.baselineContent) return false;
+      closeEditorAndActivateNeighbor();
+      return true;
+    }
+
+    return false;
+  }, []);
+
+  // Keep the hotkey ref current during render so Cmd/Ctrl+W never sees the
+  // App.tsx stub `() => false` between commit and useEffect.
+  handleRequestCloseEditorTabRef.current = handleRequestCloseEditorTab;
+
+  const handleSaveSessionRename = useCallback((name: string) => {
+    if (!sessionRenameTarget) return;
+    if (!name.trim()) return;
+    submitSessionRename(sessionRenameTarget.id, name);
+    resetSessionRename();
+  }, [resetSessionRename, sessionRenameTarget, submitSessionRename]);
+
+  const handleSaveWorkspaceRename = useCallback((name: string) => {
+    if (!workspaceRenameTarget) return;
+    if (!name.trim()) return;
+    submitWorkspaceRename(workspaceRenameTarget.id, name);
+    resetWorkspaceRename();
+  }, [resetWorkspaceRename, submitWorkspaceRename, workspaceRenameTarget]);
+
   useEffect(() => {
     const catalog = buildPluginSettingScopeCatalog({
       hosts,
@@ -224,58 +435,11 @@ function AppViewInner({ domains }: AppViewProps) {
   return (
     <SnippetExecutionProvider>
     <UnsavedChangesProvider>
-      {({ prompt }) => {
-        // Helper: close an editor tab and activate the neighbor (left-preference), or vault.
-        const closeEditorAndActivateNeighbor = (id: string) => {
-          const closingTabId = toEditorTabId(id);
-          const list = orderedTabsWithEditors;
-          const idx = list.indexOf(closingTabId);
-          releaseEditorTabSaveCoordinator(id);
-          editorTabStore.close(id);
-          if (activeTabStore.getActiveTabId() !== closingTabId) return;
-          const next = list[idx - 1] ?? list[idx + 1] ?? 'vault';
-          activeTabStore.setActiveTabId(next === closingTabId ? 'vault' : next);
-        };
-
-        // Real dirty-confirm close handler.
-        const handleRequestCloseEditorTab = async (id: string): Promise<boolean> => {
-          const tab = editorTabStore.getTab(id);
-          if (!tab) return false;
-          const dirty = tab.content !== tab.baselineContent;
-          if (!dirty) {
-            closeEditorAndActivateNeighbor(id);
-            return true;
-          }
-          const choice = await prompt(tab.fileName);
-          if (choice === 'cancel') return false;
-          if (choice === 'discard') {
-            closeEditorAndActivateNeighbor(id);
-            return true;
-          }
-          if (choice === 'save') {
-            const ok = await saveEditorTab(id);
-            if (!ok) {
-              const msg = editorTabStore.getTab(id)?.saveError ?? 'Save failed';
-              toast.error(msg, 'SFTP');
-              return false;
-            }
-            const latest = editorTabStore.getTab(id);
-            if (!latest || latest.content !== latest.baselineContent) return false;
-            closeEditorAndActivateNeighbor(id);
-            return true;
-          }
-
-          return false;
-        };
-
-        // Expose to the hotkey dispatcher (Cmd/Ctrl+W).
-        handleRequestCloseEditorTabRef.current = handleRequestCloseEditorTab;
-
-        return (
+      {() => (
     <div className="flex flex-col h-screen text-foreground font-sans netcatty-shell" data-terminal-appearance-root onContextMenu={handleRootContextMenu}>
       <TopTabs
         theme={resolvedTheme}
-        themePreference={settings.theme}
+        themePreference={themePreference}
         hosts={hosts}
         sessions={sessions}
         orphanSessions={orphanSessions}
@@ -295,21 +459,21 @@ function AppViewInner({ domains }: AppViewProps) {
         onCloseLogView={closeLogView}
         onCloseTabsBatch={closeTabsBatch}
         onOpenQuickSwitcher={handleOpenQuickSwitcher}
-        onThemeChange={settings.setTheme}
+        onThemeChange={setTheme}
         onOpenSettings={handleOpenSettings}
         externalMcpEnabled={externalMcpToggle.enabled}
         onToggleExternalMcp={externalMcpToggle.setEnabled}
         showExternalMcpToggle={!isPeerSessionWindow}
-        windowOpacity={settings.windowOpacity}
-        setWindowOpacity={settings.setWindowOpacity}
+        windowOpacity={windowOpacity}
+        setWindowOpacity={setWindowOpacity}
         onSyncNow={handleSyncNowManual}
         onStartSessionDrag={setDraggingSessionId}
         onEndSessionDrag={handleEndSessionDrag}
         onReorderTabs={reorderWorkTabs}
         onRemoveSessionFromWorkspace={removeSessionFromWorkspace}
-        showSftpTab={settings.showSftpTab}
-        showHostTreeSidebar={settings.showHostTreeSidebar}
-        dynamicTabTitleMode={settings.terminalSettings.dynamicTabTitleMode}
+        showSftpTab={showSftpTab}
+        showHostTreeSidebar={showHostTreeSidebar}
+        dynamicTabTitleMode={dynamicTabTitleMode}
         editorTabs={editorTabs}
         pluginViewTabs={pluginViewTabs}
         onClosePluginViewTab={closePluginViewTab}
@@ -319,7 +483,7 @@ function AppViewInner({ domains }: AppViewProps) {
 
       <div className="flex-1 relative min-h-0">
         <AppHostTreeLayer
-          enabled={settings.showHostTreeSidebar}
+          enabled={showHostTreeSidebar}
           hosts={hosts}
           customGroups={customGroups}
           groupConfigs={groupConfigs}
@@ -328,9 +492,7 @@ function AppViewInner({ domains }: AppViewProps) {
           editorTabs={editorTabs}
           logViews={logViews}
           orderedTabs={orderedTabsWithEditors}
-          accentMode={accentMode}
           currentTerminalTheme={currentTerminalTheme}
-          customAccent={customAccent}
           followAppTerminalTheme={followAppTerminalTheme}
           hostById={hostById}
           themeById={themeById}
@@ -365,7 +527,7 @@ function AppViewInner({ domains }: AppViewProps) {
           onUpdateHosts={updateHosts}
         />
 
-        <VaultViewContainer appThemeStyle={appThemeStyle}>
+        <AppVaultThemeSurface VaultViewContainer={VaultViewContainer}>
           <VaultView
             hosts={hosts}
             keys={keys}
@@ -373,11 +535,8 @@ function AppViewInner({ domains }: AppViewProps) {
             proxyProfiles={proxyProfiles}
             snippets={snippets}
             snippetPackages={snippetPackages}
-            notes={notes}
-            noteGroups={noteGroups}
             customGroups={customGroups}
             knownHosts={effectiveKnownHosts}
-            connectionLogs={connectionLogs}
             managedSources={managedSources}
             sessionCount={sessions.filter((s) => !s.hiddenFromTabs).length}
             hotkeyScheme={hotkeyScheme}
@@ -401,8 +560,6 @@ function AppViewInner({ domains }: AppViewProps) {
             onUpdateProxyProfiles={updateProxyProfiles}
             onUpdateSnippets={updateSnippets}
             onUpdateSnippetPackages={updateSnippetPackages}
-            onUpdateNotes={updateNotes}
-            onUpdateNoteGroups={updateNoteGroups}
             onUpdateCustomGroups={updateCustomGroups}
             onCommitPluginImporterData={commitPluginImporterData}
             onUpdateKnownHosts={updateKnownHosts}
@@ -413,14 +570,11 @@ function AppViewInner({ domains }: AppViewProps) {
             onClearAndRemoveManagedSources={clearAndRemoveSources}
             onUnmanageSource={unmanageSource}
             onConvertKnownHost={convertKnownHostToHost}
-            onToggleConnectionLogSaved={toggleConnectionLogSaved}
-            onDeleteConnectionLog={deleteConnectionLog}
-            onClearUnsavedConnectionLogs={clearUnsavedConnectionLogs}
             onRunSnippet={runSnippet}
             onOpenLogView={openLogView}
-            showRecentHosts={settings.showRecentHosts}
-            hostClickBehavior={settings.hostClickBehavior}
-            showOnlyUngroupedHostsInRoot={settings.showOnlyUngroupedHostsInRoot}
+            showRecentHosts={showRecentHosts}
+            hostClickBehavior={hostClickBehavior}
+            showOnlyUngroupedHostsInRoot={showOnlyUngroupedHostsInRoot}
             navigateToSection={navigateToSection}
             onNavigateToSectionHandled={() => setNavigateToSection(null)}
             deepLinkHostDraft={deepLinkHostDraft}
@@ -429,7 +583,7 @@ function AppViewInner({ domains }: AppViewProps) {
             onVaultFocusRequestHandled={() => setVaultFocusRequest(null)}
             terminalSettings={terminalSettings}
           />
-        </VaultViewContainer>
+        </AppVaultThemeSurface>
 
         <SftpViewMount
           hosts={terminalHosts}
@@ -464,8 +618,6 @@ function AppViewInner({ domains }: AppViewProps) {
           identities={identities}
           snippets={snippets}
           snippetPackages={snippetPackages}
-          notes={notes}
-          noteGroups={noteGroups}
           sessions={sessions}
           workspaces={workspaces}
           knownHosts={effectiveKnownHosts}
@@ -477,14 +629,12 @@ function AppViewInner({ domains }: AppViewProps) {
           clearThemeIntent={ctx.clearThemeIntent}
           settleManualThemeIntent={ctx.settleManualThemeIntent}
           resolveSessionAppearance={ctx.resolveSessionAppearance}
-          accentMode={accentMode}
-          customAccent={customAccent}
           terminalSettings={terminalSettings}
           terminalFontFamilyId={terminalFontFamilyId}
           fontSize={terminalFontSize}
           hotkeyScheme={hotkeyScheme}
-          disableTerminalFontZoom={settings.disableTerminalFontZoom}
-          restoreTerminalCwd={settings.restoreTerminalCwd}
+          disableTerminalFontZoom={disableTerminalFontZoom}
+          restoreTerminalCwd={restoreTerminalCwd}
           keyBindings={keyBindings}
           onHotkeyAction={handleHotkeyAction}
           onUpdateTerminalThemeId={handleDefaultTerminalThemeChange}
@@ -529,16 +679,14 @@ function AppViewInner({ domains }: AppViewProps) {
           updateHosts={updateTerminalHosts}
           updateSnippets={updateSnippets}
           updateSnippetPackages={updateSnippetPackages}
-          updateNotes={updateNotes}
-          updateNoteGroups={updateNoteGroups}
           sftpDefaultViewMode={sftpDefaultViewMode}
           sftpDoubleClickBehavior={sftpDoubleClickBehavior}
           sftpAutoSync={sftpAutoSync}
           sftpShowHiddenFiles={sftpShowHiddenFiles}
           sftpUseCompressedUpload={sftpUseCompressedUpload}
           sftpAutoOpenSidebar={sftpAutoOpenSidebar}
-          terminalSidePanelAutoOpen={settings.terminalSidePanelAutoOpen}
-          terminalSidePanelAutoOpenTab={settings.terminalSidePanelAutoOpenTab}
+          terminalSidePanelAutoOpen={terminalSidePanelAutoOpen}
+          terminalSidePanelAutoOpenTab={terminalSidePanelAutoOpenTab}
           sftpFollowTerminalCwd={sftpFollowTerminalCwd}
           setSftpFollowTerminalCwd={setSftpFollowTerminalCwd}
           editorWordWrap={editorWordWrap}
@@ -548,7 +696,7 @@ function AppViewInner({ domains }: AppViewProps) {
           sessionLogsFormat={sessionLogsFormat}
           sessionLogsTimestampsEnabled={sessionLogsTimestampsEnabled}
           sshDebugLogsEnabled={sshDebugLogsEnabled}
-          showHostTreeSidebar={settings.showHostTreeSidebar}
+          showHostTreeSidebar={showHostTreeSidebar}
           toggleScriptsSidePanelRef={toggleScriptsSidePanelRef}
           toggleSidePanelRef={toggleSidePanelRef}
           onStartSessionRename={startSessionRename}
@@ -556,21 +704,18 @@ function AppViewInner({ domains }: AppViewProps) {
           onRemoveSessionFromWorkspace={removeSessionFromWorkspace}
         />
 
-        {/* Log Views - readonly terminal replays */}
-        {logViews.map(logView => {
-          // Get the latest log data from connectionLogs to reflect updates
-          const latestLog = connectionLogs.find(l => l.id === logView.connectionLogId) || logView.log;
-          return (
-            <LogViewWrapper
-              key={logView.id}
-              logView={{ ...logView, log: latestLog }}
-              defaultTerminalTheme={currentTerminalTheme}
-              defaultFontSize={terminalFontSize}
-              onClose={() => closeLogView(logView.id)}
-              onUpdateLog={updateConnectionLog}
-            />
-          );
-        })}
+        {/* Log Views - readonly terminal replays. The latest log body comes
+            from connectionLogsStore inside AppLogViewSurface. */}
+        {logViews.map((logView: any) => (
+          <AppLogViewSurface
+            key={logView.id}
+            LogViewWrapper={LogViewWrapper}
+            logView={logView}
+            defaultTerminalTheme={currentTerminalTheme}
+            defaultFontSize={terminalFontSize}
+            onClose={() => closeLogView(logView.id)}
+          />
+        ))}
 
         {/* Editor Tabs — kept mounted for Monaco instance persistence; visibility toggled via CSS */}
         {editorTabs.map((tab) => (
@@ -587,10 +732,7 @@ function AppViewInner({ domains }: AppViewProps) {
           </LazyLoadBoundary>
         ))}
 
-        <AppPluginKeybindingHost
-          locale={settings.uiLanguage}
-          theme={resolvedTheme}
-          themeTokens={pluginThemeTokens}
+        <AppPluginKeybindingThemeHost
           sessions={sessions}
           workspaces={workspaces}
         />
@@ -681,7 +823,7 @@ function AppViewInner({ domains }: AppViewProps) {
               results={quickResults}
               sessions={sessions}
               workspaces={workspaces}
-              showSftpTab={settings.showSftpTab}
+              showSftpTab={showSftpTab}
               onQueryChange={setQuickSearch}
               onSelect={handleHostConnectWithProtocolCheck}
               onEditHost={(host) => {
@@ -715,59 +857,32 @@ function AppViewInner({ domains }: AppViewProps) {
         </LazyLoadBoundary>
       )}
 
-      <Dialog open={!!sessionRenameTarget} onOpenChange={(open) => {
-        if (!open) {
-          resetSessionRename();
-        }
-      }}>
-        <DialogContent className="max-w-sm">
-          <DialogHeader>
-            <DialogTitle>{t('dialog.renameSession.title')}</DialogTitle>
-          </DialogHeader>
-          <div className="space-y-2 py-2">
-            <Label htmlFor="session-name">{t('field.name')}</Label>
-            <Input
-              id="session-name"
-              value={sessionRenameValue}
-              onChange={(e) => setSessionRenameValue(e.target.value)}
-              onKeyDown={(e) => { if (e.key === 'Enter') submitSessionRename(); }}
-              autoFocus
-              placeholder={t('placeholder.sessionName')}
-            />
-          </div>
-          <DialogFooter>
-            <Button variant="ghost" onClick={resetSessionRename}>{t('common.cancel')}</Button>
-            <Button onClick={submitSessionRename} disabled={!sessionRenameValue.trim()}>{t('common.save')}</Button>
-          </DialogFooter>
-        </DialogContent>
-      </Dialog>
+      <RenameDraftDialog
+        open={!!sessionRenameTarget}
+        inputId="session-name"
+        initialName={sessionRenameTarget ? (sessionRenameTarget.customName || sessionRenameTarget.hostLabel) : ''}
+        title={t('dialog.renameSession.title')}
+        nameLabel={t('field.name')}
+        placeholder={t('placeholder.sessionName')}
+        cancelLabel={t('common.cancel')}
+        saveLabel={t('common.save')}
+        onCancel={resetSessionRename}
+        onSave={handleSaveSessionRename}
+      />
+
+      <RenameDraftDialog
+        open={!!workspaceRenameTarget}
+        inputId="workspace-name"
+        initialName={workspaceRenameTarget ? workspaceRenameTarget.title : ''}
+        title={t('dialog.renameWorkspace.title')}
+        nameLabel={t('field.name')}
+        placeholder={t('placeholder.workspaceName')}
+        cancelLabel={t('common.cancel')}
+        saveLabel={t('common.save')}
+        onCancel={resetWorkspaceRename}
+        onSave={handleSaveWorkspaceRename}
+      />
 
-      <Dialog open={!!workspaceRenameTarget} onOpenChange={(open) => {
-        if (!open) {
-          resetWorkspaceRename();
-        }
-      }}>
-        <DialogContent className="max-w-sm">
-          <DialogHeader>
-            <DialogTitle>{t('dialog.renameWorkspace.title')}</DialogTitle>
-          </DialogHeader>
-          <div className="space-y-2 py-2">
-            <Label htmlFor="workspace-name">{t('field.name')}</Label>
-            <Input
-              id="workspace-name"
-              value={workspaceRenameValue}
-              onChange={(e) => setWorkspaceRenameValue(e.target.value)}
-              onKeyDown={(e) => { if (e.key === 'Enter') submitWorkspaceRename(); }}
-              autoFocus
-              placeholder={t('placeholder.workspaceName')}
-            />
-          </div>
-          <DialogFooter>
-            <Button variant="ghost" onClick={resetWorkspaceRename}>{t('common.cancel')}</Button>
-            <Button onClick={submitWorkspaceRename} disabled={!workspaceRenameValue.trim()}>{t('common.save')}</Button>
-          </DialogFooter>
-        </DialogContent>
-      </Dialog>
 
       {isCreateWorkspaceOpen && (
         <LazyLoadBoundary name="Create workspace" resetKey="create-workspace">
@@ -871,8 +986,7 @@ function AppViewInner({ domains }: AppViewProps) {
         </DialogContent>
       </Dialog>
     </div>
-        );
-      }}
+      )}
     </UnsavedChangesProvider>
     </SnippetExecutionProvider>
   );

application/app/activeChromeTheme.test.ts

@@ -78,6 +78,30 @@ test("editor tabs use the followed terminal theme when follow-app terminal theme
   assert.equal(resolved?.id, currentTheme.id);
 });
 
+test("follow-app chrome applies custom accent onto the published base theme", () => {
+  const editorTab = {
+    id: "editor-1",
+    hostId: "host-1",
+    sessionId: "sftp-1",
+  };
+
+  const resolved = resolveActiveChromeTheme({
+    ...baseInput,
+    accentMode: "custom",
+    customAccent: "0 100% 50%",
+    activeTabId: toEditorTabId(editorTab.id),
+    editorTabs: [editorTab as unknown as EditorTab],
+    followAppTerminalTheme: true,
+    hostById: new Map([
+      ["host-1", { id: "host-1", theme: hostTheme.id } as unknown as Host],
+    ]),
+  });
+
+  assert.equal(resolved?.id, currentTheme.id);
+  assert.notEqual(resolved?.colors.cursor, currentTheme.colors.cursor);
+  assert.notEqual(resolved, currentTheme);
+});
+
 test("log tabs use the saved log theme when available", () => {
   const resolved = resolveActiveChromeTheme({
     ...baseInput,

application/app/activeChromeTheme.ts

@@ -18,12 +18,12 @@ export type ResolveActiveChromeThemeInput = {
   customAccent: string;
   editorTabs: readonly EditorTabChrome[];
   followAppTerminalTheme: boolean;
-  hostById: Map<string, Host>;
+  hostById: ReadonlyMap<string, Host>;
   logViews: readonly LogView[];
   resolveSessionAppearance?: (hostScope: TerminalAppearanceHostScope) => ResolvedAppearance;
-  sessionById: Map<string, TerminalSession>;
-  themeById: Map<string, TerminalTheme>;
-  workspaceById: Map<string, Workspace>;
+  sessionById: ReadonlyMap<string, TerminalSession>;
+  themeById: ReadonlyMap<string, TerminalTheme>;
+  workspaceById: ReadonlyMap<string, Workspace>;
 };
 
 export function isActiveChromeThemeResolvable({
@@ -68,7 +68,9 @@ export function resolveActiveChromeTheme({
   };
 
   const resolveHostTheme = (hostId: string): TerminalTheme => {
-    if (followAppTerminalTheme) return currentTerminalTheme;
+    if (followAppTerminalTheme) {
+      return applyCustomAccentToTerminalTheme(currentTerminalTheme, accentMode, customAccent);
+    }
     if (resolveSessionAppearance) {
       return resolveSessionAppearance(resolveHostScope(hostId)).theme;
     }
@@ -90,12 +92,15 @@ export function resolveActiveChromeTheme({
   const logView = logViews.find((item) => item.id === activeTabId);
   if (logView) {
     const explicitThemeId = logView.log.themeId;
-    return explicitThemeId ? themeById.get(explicitThemeId) ?? currentTerminalTheme : currentTerminalTheme;
+    const base = explicitThemeId ? themeById.get(explicitThemeId) ?? currentTerminalTheme : currentTerminalTheme;
+    return applyCustomAccentToTerminalTheme(base, accentMode, customAccent);
   }
 
   const workspace = workspaceById.get(activeTabId);
   if (workspace) {
-    if (followAppTerminalTheme) return currentTerminalTheme;
+    if (followAppTerminalTheme) {
+      return applyCustomAccentToTerminalTheme(currentTerminalTheme, accentMode, customAccent);
+    }
 
     if (workspace.viewMode === "focus") {
       const focusedSession = resolveWorkspaceTargetSessionFromMap(workspace, sessionById);

application/app/appHandlersBridge.ts

@@ -0,0 +1,64 @@
+/**
+ * Stable accessor bridge for App-local handlers that Host islands need when
+ * assembling domain bags. `AppSideEffects` registers the live glue via
+ * `useLayoutEffect`; Hosts call `getAppHandlers()` instead of receiving mega
+ * props from App.
+ *
+ * Keep this intentionally loose (`Record<string, unknown>`): the handler set
+ * tracks App glue, not a frozen public API.
+ */
+
+type Listener = () => void;
+
+export type AppHandlers = Record<string, unknown>;
+
+function handlersShallowEqual(prev: AppHandlers, next: AppHandlers): boolean {
+  const prevKeys = Object.keys(prev);
+  const nextKeys = Object.keys(next);
+  if (prevKeys.length !== nextKeys.length) return false;
+  for (const key of nextKeys) {
+    if (prev[key] !== next[key]) return false;
+  }
+  return true;
+}
+
+class AppHandlersBridge {
+  private handlers: AppHandlers | null = null;
+  private listeners = new Set<Listener>();
+
+  get = (): AppHandlers | null => this.handlers;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  set(next: AppHandlers | null): void {
+    if (this.handlers === next) return;
+    if (
+      this.handlers
+      && next
+      && handlersShallowEqual(this.handlers, next)
+    ) {
+      return;
+    }
+    this.handlers = next;
+    for (const listener of this.listeners) listener();
+  }
+}
+
+const bridge = new AppHandlersBridge();
+
+export function registerAppHandlers(handlers: AppHandlers | null): void {
+  bridge.set(handlers);
+}
+
+export function getAppHandlers(): AppHandlers | null {
+  return bridge.get();
+}
+
+export function subscribeAppHandlers(listener: Listener): () => void {
+  return bridge.subscribe(listener);
+}

application/app/appLocalUiStore.ts

@@ -0,0 +1,116 @@
+import { useSyncExternalStore } from 'react';
+
+import type { Host, PortForwardingRule } from '../../domain/models';
+import type { VaultSection } from '../../components/VaultView';
+import type { KeyboardInteractiveRequest } from '../../components/KeyboardInteractiveModal';
+import type { PassphraseRequest } from '../../components/PassphraseModal';
+
+type Listener = () => void;
+
+/**
+ * Dialog / queue / ephemeral UI owned outside the vault/session/settings
+ * mega hooks. DialogsHost / VaultHost / TerminalHost subscribe here so
+ * AppSideEffects never has to rebuild domain bags when a modal opens.
+ *
+ * `portForwardingRules` is published here as a thin derived slice: the PF
+ * hook still lives in AppSideEffects (tray / sync / auto-start), but Hosts
+ * must not receive a prepared terminal domain bag.
+ */
+export type AppLocalUiSnapshot = {
+  isQuickSwitcherOpen: boolean;
+  isCreateWorkspaceOpen: boolean;
+  addToWorkspaceDialog:
+    | { mode: 'append'; workspaceId: string }
+    | { mode: 'create' }
+    | null;
+  quickSearch: string;
+  protocolSelectHost: Host | null;
+  navigateToSection: VaultSection | null;
+  deepLinkHostDraft: Host | null;
+  ephemeralHosts: readonly Host[];
+  portForwardingRules: readonly PortForwardingRule[];
+  keyboardInteractiveQueue: readonly KeyboardInteractiveRequest[];
+  passphraseQueue: readonly PassphraseRequest[];
+  deleteHostConfirm: { hostId: string; name: string } | null;
+  vaultFocusRequest: unknown;
+  openNoteRequest: unknown;
+  emptyVaultConflict: unknown;
+};
+
+export const EMPTY_APP_LOCAL_UI: AppLocalUiSnapshot = Object.freeze({
+  isQuickSwitcherOpen: false,
+  isCreateWorkspaceOpen: false,
+  addToWorkspaceDialog: null,
+  quickSearch: '',
+  protocolSelectHost: null,
+  navigateToSection: null,
+  deepLinkHostDraft: null,
+  ephemeralHosts: Object.freeze([]) as readonly Host[],
+  portForwardingRules: Object.freeze([]) as readonly PortForwardingRule[],
+  keyboardInteractiveQueue: Object.freeze([]) as readonly KeyboardInteractiveRequest[],
+  passphraseQueue: Object.freeze([]) as readonly PassphraseRequest[],
+  deleteHostConfirm: null,
+  vaultFocusRequest: null,
+  openNoteRequest: null,
+  emptyVaultConflict: null,
+});
+class AppLocalUiStore {
+  private snapshot: AppLocalUiSnapshot = EMPTY_APP_LOCAL_UI;
+  private listeners = new Set<Listener>();
+
+  getSnapshot = (): AppLocalUiSnapshot => this.snapshot;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  setSnapshot(next: AppLocalUiSnapshot): void {
+    const prev = this.snapshot;
+    if (
+      prev.isQuickSwitcherOpen === next.isQuickSwitcherOpen
+      && prev.isCreateWorkspaceOpen === next.isCreateWorkspaceOpen
+      && prev.addToWorkspaceDialog === next.addToWorkspaceDialog
+      && prev.quickSearch === next.quickSearch
+      && prev.protocolSelectHost === next.protocolSelectHost
+      && prev.navigateToSection === next.navigateToSection
+      && prev.deepLinkHostDraft === next.deepLinkHostDraft
+      && prev.ephemeralHosts === next.ephemeralHosts
+      && prev.portForwardingRules === next.portForwardingRules
+      && prev.keyboardInteractiveQueue === next.keyboardInteractiveQueue
+      && prev.passphraseQueue === next.passphraseQueue
+      && prev.deleteHostConfirm === next.deleteHostConfirm
+      && prev.vaultFocusRequest === next.vaultFocusRequest
+      && prev.openNoteRequest === next.openNoteRequest
+      && prev.emptyVaultConflict === next.emptyVaultConflict
+    ) {
+      return;
+    }
+    this.snapshot = next;
+    for (const listener of this.listeners) listener();
+  }
+}
+
+export const appLocalUiStore = new AppLocalUiStore();
+
+export function publishAppLocalUi(snapshot: AppLocalUiSnapshot): void {
+  appLocalUiStore.setSnapshot(snapshot);
+}
+
+export function getAppLocalUiSnapshot(): AppLocalUiSnapshot {
+  return appLocalUiStore.getSnapshot();
+}
+
+export function subscribeAppLocalUi(listener: Listener): () => void {
+  return appLocalUiStore.subscribe(listener);
+}
+
+export function useAppLocalUiStore(): AppLocalUiSnapshot {
+  return useSyncExternalStore(
+    subscribeAppLocalUi,
+    getAppLocalUiSnapshot,
+    getAppLocalUiSnapshot,
+  );
+}

application/app/appShellPropsStore.ts

@@ -0,0 +1,120 @@
+import { useSyncExternalStore } from 'react';
+
+import type { KnownHost } from '../../types';
+import type { AppActiveTabChromeProps } from './AppActiveTabChrome';
+import { appViewDomainsEqual, type AppViewDomains } from './appViewDomains';
+
+type Listener = () => void;
+
+export type AppShellOverlays = {
+  onAddKnownHost: (knownHost: KnownHost) => void;
+  deleteHostConfirm: { hostId: string; name: string } | null;
+  onCancelDeleteHost: () => void;
+  onConfirmDeleteHost: () => void;
+};
+
+export type AppShellPropsSnapshot = {
+  domains: AppViewDomains | null;
+  chrome: AppActiveTabChromeProps | null;
+  overlays: AppShellOverlays | null;
+};
+
+const EMPTY: AppShellPropsSnapshot = Object.freeze({
+  domains: null,
+  chrome: null,
+  overlays: null,
+});
+
+/**
+ * Host islands publish domain / chrome / overlay bags here. `AppShell`
+ * subscribes via `useSyncExternalStore` and only re-renders when bag
+ * identities change (`appViewDomainsEqual` + chrome/overlays identity).
+ */
+class AppShellPropsStore {
+  private snapshot: AppShellPropsSnapshot = EMPTY;
+  private listeners = new Set<Listener>();
+
+  getSnapshot = (): AppShellPropsSnapshot => this.snapshot;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  setDomains(domains: AppViewDomains): void {
+    const prev = this.snapshot;
+    if (prev.domains && appViewDomainsEqual(prev.domains, domains)) {
+      return;
+    }
+    this.snapshot = { ...prev, domains };
+    for (const listener of this.listeners) listener();
+  }
+
+  setChrome(chrome: AppActiveTabChromeProps): void {
+    if (this.snapshot.chrome === chrome) return;
+    this.snapshot = { ...this.snapshot, chrome };
+    for (const listener of this.listeners) listener();
+  }
+
+  setOverlays(overlays: AppShellOverlays): void {
+    if (this.snapshot.overlays === overlays) return;
+    this.snapshot = { ...this.snapshot, overlays };
+    for (const listener of this.listeners) listener();
+  }
+
+  setDomainSlice<K extends keyof AppViewDomains>(
+    key: K,
+    slice: AppViewDomains[K],
+  ): void {
+    const prev = this.snapshot.domains;
+    if (prev && prev[key] === slice) return;
+    const domains = {
+      vault: prev?.vault ?? {},
+      terminal: prev?.terminal ?? {},
+      chrome: prev?.chrome ?? {},
+      dialogs: prev?.dialogs ?? {},
+      mounts: prev?.mounts ?? {},
+      [key]: slice,
+    } as AppViewDomains;
+    this.setDomains(domains);
+  }
+}
+
+export const appShellPropsStore = new AppShellPropsStore();
+
+export function publishAppShellDomains(domains: AppViewDomains): void {
+  appShellPropsStore.setDomains(domains);
+}
+
+export function publishAppShellDomainSlice<K extends keyof AppViewDomains>(
+  key: K,
+  slice: AppViewDomains[K],
+): void {
+  appShellPropsStore.setDomainSlice(key, slice);
+}
+
+export function publishAppShellChrome(chrome: AppActiveTabChromeProps): void {
+  appShellPropsStore.setChrome(chrome);
+}
+
+export function publishAppShellOverlays(overlays: AppShellOverlays): void {
+  appShellPropsStore.setOverlays(overlays);
+}
+
+export function getAppShellPropsSnapshot(): AppShellPropsSnapshot {
+  return appShellPropsStore.getSnapshot();
+}
+
+export function subscribeAppShellProps(listener: Listener): () => void {
+  return appShellPropsStore.subscribe(listener);
+}
+
+export function useAppShellProps(): AppShellPropsSnapshot {
+  return useSyncExternalStore(
+    subscribeAppShellProps,
+    getAppShellPropsSnapshot,
+    getAppShellPropsSnapshot,
+  );
+}

application/app/hosts/ChromeHost.tsx

@@ -0,0 +1,210 @@
+import { useCallback, useLayoutEffect, useMemo, useRef, useSyncExternalStore } from 'react';
+
+import { TERMINAL_THEMES } from '../../../infrastructure/config/terminalThemes';
+import { retainStableSessionsIgnoringPresentation } from '../../../domain/terminalPaneSessionsEqual';
+import { useI18n } from '../../i18n/I18nProvider';
+import { useCustomThemes } from '../../state/customThemeStore';
+import { useEditorTabChromeList } from '../../state/editorTabStore';
+import { toEditorTabId } from '../../state/activeTabStore';
+import {
+  getSessionSnapshotActions,
+  useSessionSnapshot,
+  useSessionSnapshotActions,
+} from '../../state/sessionSnapshotStore';
+import { useSettingsChromeStore } from '../../state/settingsChromeStore';
+import { useVaultSnapshot } from '../../state/vaultSnapshotStore';
+import {
+  getTerminalSettingsActions,
+  useTerminalSettingsStore,
+} from '../../state/terminalSettingsStore';
+import { usePluginViewTabs } from '../../state/pluginViewTabStore';
+import { getAppHandlers, subscribeAppHandlers } from '../appHandlersBridge';
+import {
+  publishAppShellChrome,
+  publishAppShellDomainSlice,
+} from '../appShellPropsStore';
+import {
+  getThemeRuntimeActions,
+  subscribeThemeRuntimeActions,
+} from '../themeRuntimeBridge';
+
+const IS_MAC_CLIENT =
+  typeof navigator !== 'undefined' && /Mac|Macintosh/.test(navigator.userAgent);
+
+/**
+ * Chrome island: TopTabs / active-tab chrome from settings chrome store,
+ * appearance chrome, and selective session/vault snapshot fields. Assembles
+ * chrome + shell chrome bags field-by-field — never spreads a prepared bag.
+ */
+export function ChromeHost() {
+  const { t } = useI18n();
+  const settingsChrome = useSettingsChromeStore();
+  const session = useSessionSnapshot();
+  const sessionActions = useSessionSnapshotActions();
+  const vault = useVaultSnapshot();
+  const terminalSettings = useTerminalSettingsStore();
+  const editorTabs = useEditorTabChromeList();
+  const pluginViewTabs = usePluginViewTabs();
+  void pluginViewTabs;
+  const customThemes = useCustomThemes();
+  const handlers = useSyncExternalStore(
+    subscribeAppHandlers,
+    getAppHandlers,
+    getAppHandlers,
+  );
+  const themeRuntime = useSyncExternalStore(
+    subscribeThemeRuntimeActions,
+    getThemeRuntimeActions,
+    getThemeRuntimeActions,
+  );
+
+  const orphanSessionsForShellRef = useRef(session.orphanSessions);
+  const orphanSessionsForShell = retainStableSessionsIgnoringPresentation(
+    orphanSessionsForShellRef.current,
+    session.orphanSessions as never,
+  );
+  orphanSessionsForShellRef.current = orphanSessionsForShell as typeof session.orphanSessions;
+
+  const themeById = useMemo(
+    () => new Map([...customThemes, ...TERMINAL_THEMES].map((theme) => [theme.id, theme])),
+    [customThemes],
+  );
+
+  const hostById = useMemo(
+    () => new Map(vault.hosts.map((host) => [host.id, host])),
+    [vault.hosts],
+  );
+
+  const sessionById = useMemo(
+    () => new Map(session.sessions.map((s) => [s.id, s])),
+    [session.sessions],
+  );
+
+  const workspaceById = useMemo(
+    () => new Map(session.workspaces.map((workspace) => [workspace.id, workspace])),
+    [session.workspaces],
+  );
+
+  const editorTabTopIds = useMemo(
+    () => editorTabs.map((tab) => toEditorTabId(tab.id)),
+    [editorTabs],
+  );
+  const pluginViewTabIds = useMemo(
+    () => pluginViewTabs.map((tab) => tab.id),
+    [pluginViewTabs],
+  );
+  const additionalWorkTabIds = useMemo(
+    () => [...editorTabTopIds, ...pluginViewTabIds],
+    [editorTabTopIds, pluginViewTabIds],
+  );
+
+  const orderedTabsWithEditors = useMemo(
+    () => sessionActions?.getOrderedWorkTabs(additionalWorkTabIds) ?? ['vault'],
+    [additionalWorkTabIds, sessionActions],
+  );
+
+  const reorderWorkTabs = useCallback((
+    draggedId: string,
+    targetId: string,
+    position: 'before' | 'after' = 'before',
+  ) => {
+    sessionActions?.reorderTabs(draggedId, targetId, position, additionalWorkTabIds);
+  }, [additionalWorkTabIds, sessionActions]);
+
+  const chromeDomain = useMemo(() => {
+    if (!handlers) return null;
+    return {
+      closeLogView: sessionActions?.closeLogView,
+      handleEndSessionDrag: handlers.handleEndSessionDrag,
+      handleOpenQuickSwitcher: handlers.handleOpenQuickSwitcher,
+      handleOpenSettings: handlers.handleOpenSettings,
+      handleRootContextMenu: handlers.handleRootContextMenu,
+      handleSyncNowManual: handlers.handleSyncNowManual,
+      isMacClient: IS_MAC_CLIENT,
+      logViews: session.logViews,
+      openLogView: sessionActions?.openLogView,
+      orderedTabsWithEditors,
+      orphanSessions: orphanSessionsForShell,
+      reorderWorkTabs,
+      resetSessionRename: sessionActions?.resetSessionRename,
+      resetWorkspaceRename: sessionActions?.resetWorkspaceRename,
+      sessionRenameTarget: session.sessionRenameTarget,
+      setActiveTabId: sessionActions?.setActiveTabId,
+      startSessionRename: sessionActions?.startSessionRename,
+      renameSessionInline: sessionActions?.renameSessionInline,
+      startWorkspaceRename: sessionActions?.startWorkspaceRename,
+      submitSessionRename: sessionActions?.submitSessionRename,
+      submitWorkspaceRename: sessionActions?.submitWorkspaceRename,
+      t,
+      themeById,
+      workspaceRenameTarget: session.workspaceRenameTarget,
+    };
+  }, [
+    handlers,
+    orderedTabsWithEditors,
+    orphanSessionsForShell,
+    reorderWorkTabs,
+    session.logViews,
+    session.sessionRenameTarget,
+    session.workspaceRenameTarget,
+    sessionActions,
+    t,
+    themeById,
+  ]);
+
+  // Call-time getters so chrome can publish before Publisher layout effects
+  // register action slots — avoids undefined applyAppTheme/setActiveTabId on
+  // the first Host publish (startup TypeError under StrictMode).
+  const setActiveTabId = useCallback((id: string) => {
+    getSessionSnapshotActions()?.setActiveTabId?.(id);
+  }, []);
+  const applyAppTheme = useCallback(() => {
+    getTerminalSettingsActions()?.applyAppTheme?.();
+  }, []);
+
+  const appShellChrome = useMemo(() => {
+    if (!handlers) return null;
+    // Theme runtime actions may still be null on the first paint before
+    // TerminalHost registers them; wait so AppActiveTabChrome never mounts
+    // with a missing resolveSessionAppearance / currentTerminalTheme.
+    if (!themeRuntime?.currentTerminalTheme || !themeRuntime?.resolveFocusedAppearance) {
+      return null;
+    }
+    return {
+      showSftpTab: settingsChrome.showSftpTab,
+      setActiveTabId,
+      applyAppTheme,
+      hostById,
+      sessionById,
+      themeById,
+      workspaceById,
+      currentTerminalTheme: themeRuntime.currentTerminalTheme,
+      followAppTerminalTheme: terminalSettings.followAppTerminalTheme,
+      editorTabs,
+      logViews: session.logViews,
+      resolveSessionAppearance: themeRuntime.resolveFocusedAppearance,
+      t,
+    };
+  }, [
+    applyAppTheme,
+    editorTabs,
+    handlers,
+    hostById,
+    session.logViews,
+    sessionById,
+    setActiveTabId,
+    settingsChrome.showSftpTab,
+    t,
+    terminalSettings.followAppTerminalTheme,
+    themeById,
+    themeRuntime,
+    workspaceById,
+  ]);
+
+  useLayoutEffect(() => {
+    if (chromeDomain) publishAppShellDomainSlice('chrome', chromeDomain);
+    if (appShellChrome) publishAppShellChrome(appShellChrome as never);
+  }, [appShellChrome, chromeDomain]);
+
+  return null;
+}

application/app/hosts/DialogsHost.tsx

@@ -0,0 +1,107 @@
+import { useLayoutEffect, useMemo, useSyncExternalStore } from 'react';
+
+import { getHostSearchMatch } from '../../../lib/searchMatcher';
+import type { Host } from '../../../types';
+import { useEditorTabChromeList } from '../../state/editorTabStore';
+import { useVaultSnapshot } from '../../state/vaultSnapshotStore';
+import { getAppHandlers, subscribeAppHandlers } from '../appHandlersBridge';
+import {
+  publishAppShellDomainSlice,
+  publishAppShellOverlays,
+} from '../appShellPropsStore';
+import { useAppLocalUiStore } from '../appLocalUiStore';
+
+const EMPTY_HOST_RESULTS: Host[] = [];
+
+/**
+ * Dialogs island: local dialog/queue state from `appLocalUiStore`, plus a
+ * selective vault hosts subscription for quick-search results when open.
+ * Assembles dialogs + overlays field-by-field — never spreads a prepared bag.
+ */
+export function DialogsHost() {
+  const local = useAppLocalUiStore();
+  const vault = useVaultSnapshot();
+  const editorTabs = useEditorTabChromeList();
+  const handlers = useSyncExternalStore(
+    subscribeAppHandlers,
+    getAppHandlers,
+    getAppHandlers,
+  );
+
+  const quickResults = useMemo(() => {
+    if (!local.isQuickSwitcherOpen) return EMPTY_HOST_RESULTS;
+    const term = local.quickSearch.trim();
+    if (!term) return vault.hosts as Host[];
+    return (vault.hosts as Host[])
+      .map((host) => ({ host, match: getHostSearchMatch(term, host) }))
+      .filter((entry) => entry.match.matched)
+      .sort((left, right) => {
+        if (left.match.score !== right.match.score) {
+          return right.match.score - left.match.score;
+        }
+        return left.host.label.localeCompare(right.host.label);
+      })
+      .map((entry) => entry.host);
+  }, [local.isQuickSwitcherOpen, local.quickSearch, vault.hosts]);
+
+  const dialogsDomain = useMemo(() => {
+    if (!handlers) return null;
+    return {
+      addToWorkspaceDialog: local.addToWorkspaceDialog,
+      clearAndRemoveSource: handlers.clearAndRemoveSource,
+      clearAndRemoveSources: handlers.clearAndRemoveSources,
+      editorTabs,
+      emptyVaultConflict: local.emptyVaultConflict,
+      handleHostConnectWithProtocolCheck: handlers.handleHostConnectWithProtocolCheck,
+      handleKeyboardInteractiveCancel: handlers.handleKeyboardInteractiveCancel,
+      handleKeyboardInteractiveSubmit: handlers.handleKeyboardInteractiveSubmit,
+      handlePassphraseCancel: handlers.handlePassphraseCancel,
+      handlePassphraseSkip: handlers.handlePassphraseSkip,
+      handlePassphraseSubmit: handlers.handlePassphraseSubmit,
+      handleProtocolSelect: handlers.handleProtocolSelect,
+      handleRequestCloseEditorTabRef: handlers.handleRequestCloseEditorTabRef,
+      isCreateWorkspaceOpen: local.isCreateWorkspaceOpen,
+      isQuickSwitcherOpen: local.isQuickSwitcherOpen,
+      keyboardInteractiveQueue: local.keyboardInteractiveQueue,
+      passphraseQueue: local.passphraseQueue,
+      protocolSelectHost: local.protocolSelectHost,
+      quickResults,
+      quickSearch: local.quickSearch,
+      resolveEmptyVaultConflict: handlers.resolveEmptyVaultConflict,
+      setAddToWorkspaceDialog: handlers.setAddToWorkspaceDialog,
+      setIsCreateWorkspaceOpen: handlers.setIsCreateWorkspaceOpen,
+      setIsQuickSwitcherOpen: handlers.setIsQuickSwitcherOpen,
+      setProtocolSelectHost: handlers.setProtocolSelectHost,
+      setQuickSearch: handlers.setQuickSearch,
+    };
+  }, [
+    editorTabs,
+    handlers,
+    local.addToWorkspaceDialog,
+    local.emptyVaultConflict,
+    local.isCreateWorkspaceOpen,
+    local.isQuickSwitcherOpen,
+    local.keyboardInteractiveQueue,
+    local.passphraseQueue,
+    local.protocolSelectHost,
+    local.quickSearch,
+    quickResults,
+  ]);
+
+  const overlays = useMemo(() => {
+    if (!handlers) return null;
+    return {
+      onAddKnownHost: handlers.handleAddKnownHost as (knownHost: never) => void,
+      deleteHostConfirm: local.deleteHostConfirm,
+      onCancelDeleteHost: handlers.handleCancelDeleteHost as () => void,
+      onConfirmDeleteHost: handlers.handleConfirmDeleteHost as () => void,
+    };
+  }, [handlers, local.deleteHostConfirm]);
+
+  useLayoutEffect(() => {
+    if (dialogsDomain) publishAppShellDomainSlice('dialogs', dialogsDomain);
+    if (overlays) publishAppShellOverlays(overlays as never);
+  }, [dialogsDomain, overlays]);
+
+  return null;
+}

application/app/hosts/TerminalHost.tsx

@@ -0,0 +1,279 @@
+import { useCallback, useLayoutEffect, useMemo, useRef, useSyncExternalStore } from 'react';
+
+import { TERMINAL_THEME_AUTO } from '../../../domain/terminalAppearance';
+import { retainStableSessionsIgnoringPresentation } from '../../../domain/terminalPaneSessionsEqual';
+import { getAppSettingsRuntime } from '../../state/appRuntimeBridge';
+import { useAppearanceChromeStore } from '../../state/appearanceChromeStore';
+import { useCustomThemes } from '../../state/customThemeStore';
+import {
+  useSessionSnapshot,
+  useSessionSnapshotActions,
+} from '../../state/sessionSnapshotStore';
+import {
+  useSettingsChromeActions,
+  useSettingsChromeStore,
+} from '../../state/settingsChromeStore';
+import {
+  useTerminalSettingsActions,
+  useTerminalSettingsStore,
+} from '../../state/terminalSettingsStore';
+import { useThemeRuntime, useTerminalAppearanceInjection } from '../../state/useThemeRuntime';
+import {
+  useVaultSnapshot,
+  useVaultSnapshotActions,
+} from '../../state/vaultSnapshotStore';
+import { getAppHandlers, subscribeAppHandlers } from '../appHandlersBridge';
+import { publishAppShellDomainSlice } from '../appShellPropsStore';
+import { useAppLocalUiStore } from '../appLocalUiStore';
+import { registerThemeRuntimeActions } from '../themeRuntimeBridge';
+
+/**
+ * Terminal island: sessions from `sessionSnapshotStore`, terminal settings
+ * from `terminalSettingsStore`, mutators via snapshot actions, theme runtime
+ * owned here, glue handlers from the app handlers bridge. Assembles the full
+ * terminal domain bag field-by-field — never spreads a prepared bag.
+ */
+export function TerminalHost() {
+  const session = useSessionSnapshot();
+  const sessionActions = useSessionSnapshotActions();
+  const vault = useVaultSnapshot();
+  const vaultActions = useVaultSnapshotActions();
+  const terminalSettings = useTerminalSettingsStore();
+  const terminalSettingsActions = useTerminalSettingsActions();
+  const {
+    followAppTerminalTheme,
+    terminalThemeId,
+    terminalThemeDarkId,
+    terminalThemeLightId,
+  } = terminalSettings;
+  const settingsChrome = useSettingsChromeStore();
+  const settingsChromeActions = useSettingsChromeActions();
+  const appearance = useAppearanceChromeStore();
+  const customThemes = useCustomThemes();
+  const local = useAppLocalUiStore();
+  const handlers = useSyncExternalStore(
+    subscribeAppHandlers,
+    getAppHandlers,
+    getAppHandlers,
+  );
+
+  // Call-time getters: SettingsPublisher registers the runtime in a layout
+  // effect after this Host's first render. Capturing noop setters into
+  // useThemeRuntime would permanently drop follow-app UI theme persistence.
+  const setLightUiThemeId = useCallback((id: string) => {
+    getAppSettingsRuntime()?.setLightUiThemeId?.(id);
+  }, []);
+  const setDarkUiThemeId = useCallback((id: string) => {
+    getAppSettingsRuntime()?.setDarkUiThemeId?.(id);
+  }, []);
+
+  const themeRuntime = useThemeRuntime({
+    terminalThemeId,
+    terminalThemeDarkId,
+    terminalThemeLightId,
+    followAppTerminalTheme,
+    resolvedTheme: settingsChrome.resolvedTheme,
+    lightUiThemeId: settingsChrome.lightUiThemeId,
+    darkUiThemeId: settingsChrome.darkUiThemeId,
+    accentMode: appearance.accentMode,
+    customAccent: appearance.customAccent,
+    customThemes,
+    setTheme: settingsChromeActions.setTheme,
+    setLightUiThemeId,
+    setDarkUiThemeId,
+  });
+
+  const {
+    globalAppearance,
+    accentedGlobalAppearance,
+    clearIntent: clearThemeIntent,
+    settleManualIntent: settleManualThemeIntent,
+    pickTheme: pickTerminalTheme,
+    resolveFocusedAppearance,
+    currentTerminalTheme,
+  } = themeRuntime;
+
+  // Inject live accent into CSS vars without publishing accented theme identity
+  // into the terminal domain bag (accent drag must not rebuild AppShell).
+  useTerminalAppearanceInjection(accentedGlobalAppearance, {
+    includeChromeSurfaces: followAppTerminalTheme,
+  });
+
+  const prevFollowAppTerminalThemeRef = useRef(followAppTerminalTheme);
+  useLayoutEffect(() => {
+    if (prevFollowAppTerminalThemeRef.current === followAppTerminalTheme) return;
+    prevFollowAppTerminalThemeRef.current = followAppTerminalTheme;
+    clearThemeIntent();
+  }, [followAppTerminalTheme, clearThemeIntent]);
+
+  // Bridge exposes the stable base theme only — ChromeHost must not republish
+  // when accentedGlobalAppearance identity churns during color-picker drag.
+  const themeBridgeActions = useMemo(() => ({
+    clearThemeIntent,
+    settleManualThemeIntent,
+    pickTerminalTheme,
+    resolveFocusedAppearance: resolveFocusedAppearance as (...args: never[]) => unknown,
+    currentTerminalTheme,
+    globalAppearance,
+  }), [
+    clearThemeIntent,
+    currentTerminalTheme,
+    globalAppearance,
+    pickTerminalTheme,
+    resolveFocusedAppearance,
+    settleManualThemeIntent,
+  ]);
+
+  useLayoutEffect(() => {
+    registerThemeRuntimeActions(themeBridgeActions);
+    return () => {
+      registerThemeRuntimeActions(null);
+    };
+  }, [themeBridgeActions]);
+
+  const sessionsForShellRef = useRef(session.sessions);
+  const sessionsForShell = retainStableSessionsIgnoringPresentation(
+    sessionsForShellRef.current,
+    session.sessions as never,
+  );
+  sessionsForShellRef.current = sessionsForShell as typeof session.sessions;
+
+  const hostById = useMemo(
+    () => new Map(vault.hosts.map((host) => [host.id, host])),
+    [vault.hosts],
+  );
+
+  const terminalHosts = useMemo(
+    () => (
+      local.ephemeralHosts.length > 0
+        ? [...vault.hosts, ...local.ephemeralHosts]
+        : vault.hosts
+    ),
+    [local.ephemeralHosts, vault.hosts],
+  );
+
+  const handleDefaultTerminalThemeChange = useCallback((themeId: string) => {
+    // Persist the default theme for ephemeral/manual hosts. Mode overrides
+    // reset to auto so the chosen theme becomes the new baseline for the
+    // current resolved UI mode (same behavior as pre-Host App).
+    terminalSettingsActions?.setTerminalThemeId(themeId);
+    if (settingsChrome.resolvedTheme === 'dark') {
+      terminalSettingsActions?.setTerminalThemeDarkId(TERMINAL_THEME_AUTO);
+    } else {
+      terminalSettingsActions?.setTerminalThemeLightId(TERMINAL_THEME_AUTO);
+    }
+  }, [settingsChrome.resolvedTheme, terminalSettingsActions]);
+
+  const handleFollowAppTerminalThemeChange = useCallback((themeId: string) => {
+    pickTerminalTheme(themeId);
+  }, [pickTerminalTheme]);
+
+  const terminalDomain = useMemo(() => {
+    if (!handlers) return null;
+    return {
+      addSessionToWorkspace: sessionActions?.addSessionToWorkspace,
+      appendHostToWorkspace: sessionActions?.appendHostToWorkspace,
+      appendLocalTerminalToWorkspace: sessionActions?.appendLocalTerminalToWorkspace,
+      clearSessionFontSizeOverride: sessionActions?.clearSessionFontSizeOverride,
+      closeSession: sessionActions?.closeSession,
+      closeTabsBatch: handlers.closeTabsBatch,
+      copySessionWithCurrentShell: handlers.copySessionWithCurrentShell,
+      copyWorkspaceWithCurrentShell: handlers.copyWorkspaceWithCurrentShell,
+      copySessionToNewWindowWithCurrentShell: handlers.copySessionToNewWindowWithCurrentShell,
+      closeWorkspace: sessionActions?.closeWorkspace,
+      createWorkspaceFromSessions: sessionActions?.createWorkspaceFromSessions,
+      createWorkspaceFromTargets: handlers.createWorkspaceFromTargets,
+      createWorkspaceWithHosts: handlers.createWorkspaceWithHosts,
+      currentTerminalTheme,
+      draggingSessionId: session.draggingSessionId,
+      editorWordWrap: terminalSettings.editorWordWrap,
+      followAppTerminalTheme: terminalSettings.followAppTerminalTheme,
+      clearThemeIntent,
+      settleManualThemeIntent,
+      pickTerminalTheme,
+      resolveSessionAppearance: resolveFocusedAppearance,
+      handleConnectSerial: handlers.handleConnectSerial,
+      handleConnectToHost: handlers.handleConnectToHost,
+      handleCreateLocalTerminal: handlers.handleCreateLocalTerminal,
+      handleDefaultTerminalThemeChange,
+      handleFollowAppTerminalThemeChange,
+      handleHotkeyAction: handlers.handleHotkeyAction,
+      handleSessionStatusChange: handlers.handleSessionStatusChange,
+      handleTerminalDataCapture: handlers.handleTerminalDataCapture,
+      handleUpdateHostFromTerminal: handlers.handleUpdateHostFromTerminal,
+      hostById,
+      terminalHosts,
+      updateTerminalHosts: handlers.updateTerminalHosts,
+      hotkeyScheme: terminalSettings.hotkeyScheme,
+      isBroadcastEnabled: sessionActions?.isBroadcastEnabled,
+      keyBindings: terminalSettings.keyBindings,
+      openNoteRequest: local.openNoteRequest,
+      portForwardingRules: local.portForwardingRules,
+      removeSessionFromWorkspace: sessionActions?.removeSessionFromWorkspace,
+      reorderWorkspaceSessions: sessionActions?.reorderWorkspaceSessions,
+      runSnippet: handlers.runSnippet,
+      sessionLogsDir: terminalSettings.sessionLogsDir,
+      sessionLogsEnabled: terminalSettings.sessionLogsEnabled,
+      sessionLogsFormat: terminalSettings.sessionLogsFormat,
+      sessionLogsTimestampsEnabled: terminalSettings.sessionLogsTimestampsEnabled,
+      sessions: sessionsForShell,
+      setDraggingSessionId: sessionActions?.setDraggingSessionId,
+      setEditorWordWrap: terminalSettingsActions?.setEditorWordWrap,
+      setTerminalFontFamilyId: terminalSettingsActions?.setTerminalFontFamilyId,
+      setTerminalFontSize: terminalSettingsActions?.setTerminalFontSize,
+      setWorkspaceFocusedSession: sessionActions?.setWorkspaceFocusedSession,
+      sftpAutoOpenSidebar: terminalSettings.sftpAutoOpenSidebar,
+      sftpFollowTerminalCwd: terminalSettings.sftpFollowTerminalCwd,
+      setSftpFollowTerminalCwd: terminalSettingsActions?.setSftpFollowTerminalCwd,
+      sftpAutoSync: terminalSettings.sftpAutoSync,
+      sftpDefaultViewMode: terminalSettings.sftpDefaultViewMode,
+      sftpDoubleClickBehavior: terminalSettings.sftpDoubleClickBehavior,
+      sftpShowHiddenFiles: terminalSettings.sftpShowHiddenFiles,
+      sftpUseCompressedUpload: terminalSettings.sftpUseCompressedUpload,
+      splitSessionWithCurrentShell: handlers.splitSessionWithCurrentShell,
+      sshDebugLogsEnabled: terminalSettings.sshDebugLogsEnabled,
+      terminalFontFamilyId: terminalSettings.terminalFontFamilyId,
+      terminalFontSize: terminalSettings.terminalFontSize,
+      terminalSettings: terminalSettings.terminalSettings,
+      terminalThemeId: terminalSettings.terminalThemeId,
+      toggleBroadcast: sessionActions?.toggleBroadcast,
+      toggleScriptsSidePanelRef: handlers.toggleScriptsSidePanelRef,
+      toggleSidePanelRef: handlers.toggleSidePanelRef,
+      toggleWorkspaceViewMode: sessionActions?.toggleWorkspaceViewMode,
+      updateHostDistro: vaultActions?.updateHostDistro,
+      updateSplitSizes: sessionActions?.updateSplitSizes,
+      updateSessionFontSize: sessionActions?.updateSessionFontSize,
+      updateSessionRestoreCwd: sessionActions?.updateSessionRestoreCwd,
+      updateSessionDynamicTitle: sessionActions?.updateSessionDynamicTitle,
+      updateSessionCodingCliProvider: sessionActions?.updateSessionCodingCliProvider,
+      updateTerminalSetting: terminalSettingsActions?.updateTerminalSetting,
+      workspaces: session.workspaces,
+    };
+  }, [
+    clearThemeIntent,
+    currentTerminalTheme,
+    handleDefaultTerminalThemeChange,
+    handleFollowAppTerminalThemeChange,
+    handlers,
+    hostById,
+    local.openNoteRequest,
+    local.portForwardingRules,
+    pickTerminalTheme,
+    resolveFocusedAppearance,
+    session.draggingSessionId,
+    session.workspaces,
+    sessionActions,
+    sessionsForShell,
+    settleManualThemeIntent,
+    terminalHosts,
+    terminalSettings,
+    terminalSettingsActions,
+    vaultActions,
+  ]);
+
+  useLayoutEffect(() => {
+    if (terminalDomain) publishAppShellDomainSlice('terminal', terminalDomain);
+  }, [terminalDomain]);
+
+  return null;
+}

application/app/hosts/VaultHost.tsx

@@ -0,0 +1,104 @@
+import { useLayoutEffect, useMemo, useSyncExternalStore } from 'react';
+
+import { getEffectiveKnownHosts } from '../../../infrastructure/syncHelpers';
+import {
+  useVaultSnapshot,
+  useVaultSnapshotActions,
+} from '../../state/vaultSnapshotStore';
+import { getAppHandlers, subscribeAppHandlers } from '../appHandlersBridge';
+import { publishAppShellDomainSlice } from '../appShellPropsStore';
+import { useAppLocalUiStore } from '../appLocalUiStore';
+import { APP_MOUNTS_DOMAIN } from './mountsDomain';
+
+/**
+ * Vault island: catalog from `vaultSnapshotStore`, glue handlers from the
+ * app handlers bridge, local vault UI from `appLocalUiStore`. Assembles the
+ * full vault domain bag field-by-field — never spreads a prepared bag from
+ * AppSideEffects.
+ */
+export function VaultHost() {
+  const vault = useVaultSnapshot();
+  const actions = useVaultSnapshotActions();
+  const local = useAppLocalUiStore();
+  const handlers = useSyncExternalStore(
+    subscribeAppHandlers,
+    getAppHandlers,
+    getAppHandlers,
+  );
+
+  const effectiveKnownHosts = useMemo(
+    () => getEffectiveKnownHosts(vault.knownHosts as never) ?? [],
+    [vault.knownHosts],
+  );
+
+  const vaultDomain = useMemo(() => {
+    if (!handlers) return null;
+    return {
+      addShellHistoryEntry: actions?.addShellHistoryEntry,
+      removeShellHistoryEntry: actions?.removeShellHistoryEntry,
+      commitPluginImporterData: actions?.commitPluginImporterData,
+      commitVaultImportTransaction: actions?.commitVaultImportTransaction,
+      convertKnownHostToHost: actions?.convertKnownHostToHost,
+      customGroups: vault.customGroups,
+      deepLinkHostDraft: local.deepLinkHostDraft,
+      effectiveKnownHosts,
+      groupConfigs: vault.groupConfigs,
+      handleAddKnownHost: handlers.handleAddKnownHost,
+      handleDeleteHost: handlers.handleDeleteHost,
+      handleOpenHostFromVaultNote: handlers.handleOpenHostFromVaultNote,
+      handleOpenVaultHostFromChat: handlers.handleOpenVaultHostFromChat,
+      handleOpenVaultNoteFromChat: handlers.handleOpenVaultNoteFromChat,
+      handleOpenVaultSectionFromChat: handlers.handleOpenVaultSectionFromChat,
+      handleOpenVaultSnippetFromChat: handlers.handleOpenVaultSnippetFromChat,
+      hosts: vault.hosts,
+      identities: vault.identities,
+      importOrReuseKey: actions?.importOrReuseKey,
+      keys: vault.keys,
+      managedSources: vault.managedSources,
+      navigateToSection: local.navigateToSection,
+      proxyProfiles: vault.proxyProfiles,
+      readPersistedHosts: actions?.readPersistedHosts,
+      readPersistedManagedSources: actions?.readPersistedManagedSources,
+      setDeepLinkHostDraft: handlers.setDeepLinkHostDraft,
+      setNavigateToSection: handlers.setNavigateToSection,
+      setVaultFocusRequest: handlers.setVaultFocusRequest,
+      snippetPackages: vault.snippetPackages,
+      snippets: vault.snippets,
+      unmanageSource: handlers.unmanageSource,
+      updateCustomGroups: actions?.updateCustomGroups,
+      updateGroupConfigs: actions?.updateGroupConfigs,
+      updateHosts: actions?.updateHosts,
+      updateIdentities: actions?.updateIdentities,
+      updateKeys: actions?.updateKeys,
+      updateKnownHosts: actions?.updateKnownHosts,
+      updateManagedSources: actions?.updateManagedSources,
+      updateProxyProfiles: actions?.updateProxyProfiles,
+      updateSnippetPackages: actions?.updateSnippetPackages,
+      updateSnippets: actions?.updateSnippets,
+      vaultFocusRequest: local.vaultFocusRequest,
+    };
+  }, [
+    actions,
+    effectiveKnownHosts,
+    handlers,
+    local.deepLinkHostDraft,
+    local.navigateToSection,
+    local.vaultFocusRequest,
+    vault.customGroups,
+    vault.groupConfigs,
+    vault.hosts,
+    vault.identities,
+    vault.keys,
+    vault.managedSources,
+    vault.proxyProfiles,
+    vault.snippetPackages,
+    vault.snippets,
+  ]);
+
+  useLayoutEffect(() => {
+    if (vaultDomain) publishAppShellDomainSlice('vault', vaultDomain);
+    publishAppShellDomainSlice('mounts', APP_MOUNTS_DOMAIN);
+  }, [vaultDomain]);
+
+  return null;
+}

application/app/hosts/mountsDomain.ts

@@ -0,0 +1,9 @@
+import { LogViewWrapper, SftpViewMount, TerminalLayerMount, VaultViewContainer } from '../AppMounts';
+
+/** Lazy mount wrappers — stable module identity for the app lifetime. */
+export const APP_MOUNTS_DOMAIN = Object.freeze({
+  VaultViewContainer,
+  SftpViewMount,
+  TerminalLayerMount,
+  LogViewWrapper,
+});

application/app/publishers/SessionPublisher.tsx

@@ -0,0 +1,217 @@
+import { useLayoutEffect, useMemo } from 'react';
+
+import {
+  AppSessionRuntimeContext,
+  registerAppSessionRuntime,
+} from '../../state/appRuntimeBridge';
+import {
+  publishSessionSnapshot,
+  registerSessionSnapshotActions,
+} from '../../state/sessionSnapshotStore';
+import { useSessionState } from '../../state/useSessionState';
+import type { ReactNode } from 'react';
+
+export type SessionPublisherProps = {
+  /** Peer session windows must not write the main window's restore record. */
+  persistSessionRestore: boolean;
+  children?: ReactNode;
+};
+
+/**
+ * Owns `useSessionState` and publishes it the same three ways `VaultPublisher`
+ * publishes the vault: catalog into `sessionSnapshotStore`, mutators into its
+ * action slot, and the whole runtime onto `appRuntimeBridge` for App.
+ */
+export function SessionPublisher({ persistSessionRestore, children }: SessionPublisherProps) {
+  const session = useSessionState({ persistSessionRestore });
+  const {
+    sessions,
+    orphanSessions,
+    workspaces,
+    logViews,
+    draggingSessionId,
+    sessionRenameTarget,
+    workspaceRenameTarget,
+    setActiveTabId,
+    closeSession,
+    closeSessions,
+    closeWorkspace,
+    openLogView,
+    closeLogView,
+    setDraggingSessionId,
+    startSessionRename,
+    renameSessionInline,
+    submitSessionRename,
+    resetSessionRename,
+    startWorkspaceRename,
+    submitWorkspaceRename,
+    resetWorkspaceRename,
+    removeSessionFromWorkspace,
+    setWorkspaceFocusedSession,
+    toggleWorkspaceViewMode,
+    createLocalTerminal,
+    createSerialSession,
+    connectToHost,
+    updateSessionStatus,
+    updateSessionFontSize,
+    clearSessionFontSizeOverride,
+    createWorkspaceWithHosts,
+    createWorkspaceFromSessions,
+    addSessionToWorkspace,
+    appendHostToWorkspace,
+    appendLocalTerminalToWorkspace,
+    createWorkspaceFromTargets,
+    updateSplitSizes,
+    splitSession,
+    reorderWorkspaceSessions,
+    moveFocusInWorkspace,
+    runSnippet,
+    getOrderedWorkTabs,
+    reorderTabs,
+    toggleBroadcast,
+    isBroadcastEnabled,
+    copySession,
+    copyWorkspace,
+    createSessionFromCloneSource,
+    updateSessionRestoreCwd,
+    getSessionRestoreCwd,
+    updateSessionDynamicTitle,
+    updateSessionCodingCliProvider,
+  } = session;
+
+  useLayoutEffect(() => {
+    registerAppSessionRuntime(session);
+  }, [session]);
+
+  // Only a real unmount clears the slot; see VaultPublisher for why.
+  useLayoutEffect(() => () => {
+    registerAppSessionRuntime(null);
+  }, []);
+
+  useLayoutEffect(() => {
+    publishSessionSnapshot({
+      sessions,
+      orphanSessions,
+      workspaces,
+      logViews,
+      draggingSessionId,
+      sessionRenameTarget,
+      workspaceRenameTarget,
+    });
+  }, [
+    draggingSessionId,
+    logViews,
+    orphanSessions,
+    sessionRenameTarget,
+    sessions,
+    workspaceRenameTarget,
+    workspaces,
+  ]);
+
+  const sessionActions = useMemo(() => ({
+    setActiveTabId,
+    closeSession,
+    closeSessions,
+    closeWorkspace,
+    openLogView,
+    closeLogView,
+    setDraggingSessionId,
+    startSessionRename,
+    renameSessionInline,
+    submitSessionRename,
+    resetSessionRename,
+    startWorkspaceRename,
+    submitWorkspaceRename,
+    resetWorkspaceRename,
+    removeSessionFromWorkspace,
+    setWorkspaceFocusedSession,
+    toggleWorkspaceViewMode,
+    createLocalTerminal,
+    createSerialSession,
+    connectToHost,
+    updateSessionStatus,
+    updateSessionFontSize,
+    clearSessionFontSizeOverride,
+    createWorkspaceWithHosts,
+    createWorkspaceFromSessions,
+    addSessionToWorkspace,
+    appendHostToWorkspace,
+    appendLocalTerminalToWorkspace,
+    createWorkspaceFromTargets,
+    updateSplitSizes,
+    splitSession,
+    reorderWorkspaceSessions,
+    moveFocusInWorkspace,
+    runSnippet,
+    getOrderedWorkTabs,
+    reorderTabs,
+    toggleBroadcast,
+    isBroadcastEnabled,
+    copySession,
+    copyWorkspace,
+    createSessionFromCloneSource,
+    updateSessionRestoreCwd,
+    getSessionRestoreCwd,
+    updateSessionDynamicTitle,
+    updateSessionCodingCliProvider,
+  }), [
+    addSessionToWorkspace,
+    appendHostToWorkspace,
+    appendLocalTerminalToWorkspace,
+    clearSessionFontSizeOverride,
+    closeLogView,
+    closeSession,
+    closeSessions,
+    closeWorkspace,
+    connectToHost,
+    copySession,
+    copyWorkspace,
+    createLocalTerminal,
+    createSerialSession,
+    createSessionFromCloneSource,
+    createWorkspaceFromSessions,
+    createWorkspaceFromTargets,
+    createWorkspaceWithHosts,
+    getOrderedWorkTabs,
+    getSessionRestoreCwd,
+    isBroadcastEnabled,
+    moveFocusInWorkspace,
+    openLogView,
+    removeSessionFromWorkspace,
+    renameSessionInline,
+    reorderTabs,
+    reorderWorkspaceSessions,
+    resetSessionRename,
+    resetWorkspaceRename,
+    runSnippet,
+    setActiveTabId,
+    setDraggingSessionId,
+    setWorkspaceFocusedSession,
+    splitSession,
+    startSessionRename,
+    startWorkspaceRename,
+    submitSessionRename,
+    submitWorkspaceRename,
+    toggleBroadcast,
+    toggleWorkspaceViewMode,
+    updateSessionCodingCliProvider,
+    updateSessionDynamicTitle,
+    updateSessionFontSize,
+    updateSessionRestoreCwd,
+    updateSessionStatus,
+    updateSplitSizes,
+  ]);
+
+  useLayoutEffect(() => {
+    registerSessionSnapshotActions(sessionActions);
+    return () => {
+      registerSessionSnapshotActions(null);
+    };
+  }, [sessionActions]);
+
+  return (
+    <AppSessionRuntimeContext.Provider value={session}>
+      {children}
+    </AppSessionRuntimeContext.Provider>
+  );
+}

application/app/publishers/SettingsPublisher.tsx

@@ -0,0 +1,47 @@
+import { useLayoutEffect, type ReactNode } from 'react';
+
+import {
+  AppSettingsRuntimeContext,
+  registerAppSettingsRuntime,
+} from '../../state/appRuntimeBridge';
+import { useSettingsState } from '../../state/useSettingsState';
+
+export type SettingsPublisherProps = {
+  /** Peer session windows must not drive the main window's settings IPC sync. */
+  enableSettingsSync: boolean;
+  /** Peer session windows must not re-apply OS-level system settings effects. */
+  enableSystemEffects: boolean;
+  children?: ReactNode;
+};
+
+/**
+ * Owns `useSettingsState` and hands it to consumers the same way
+ * `VaultPublisher` / `SessionPublisher` hand over their runtimes: a context for
+ * render-time reads and the `appRuntimeBridge` slot for imperative callers.
+ *
+ * The store fan-out (`settingsChromeStore` / `appearanceChromeStore`) already
+ * happens inside `useSettingsState`, so this publisher only relocates the hook
+ * out of the component that also builds the shell's domain bags.
+ */
+export function SettingsPublisher({
+  enableSettingsSync,
+  enableSystemEffects,
+  children,
+}: SettingsPublisherProps) {
+  const settings = useSettingsState({ enableSettingsSync, enableSystemEffects });
+
+  useLayoutEffect(() => {
+    registerAppSettingsRuntime(settings);
+  }, [settings]);
+
+  // Only a real unmount clears the slot; see VaultPublisher for why.
+  useLayoutEffect(() => () => {
+    registerAppSettingsRuntime(null);
+  }, []);
+
+  return (
+    <AppSettingsRuntimeContext.Provider value={settings}>
+      {children}
+    </AppSettingsRuntimeContext.Provider>
+  );
+}

application/app/publishers/VaultPublisher.tsx

@@ -0,0 +1,197 @@
+import { useLayoutEffect, useMemo, useRef, type ReactNode } from 'react';
+
+import {
+  AppVaultRuntimeContext,
+  registerAppVaultRuntime,
+  type AppVaultContextValue,
+} from '../../state/appRuntimeBridge';
+import {
+  publishVaultSnapshot,
+  registerVaultSnapshotActions,
+} from '../../state/vaultSnapshotStore';
+import { useVaultState } from '../../state/useVaultState';
+import { getEffectiveKnownHosts } from '../../../infrastructure/syncHelpers';
+
+export type VaultPublisherProps = {
+  children?: ReactNode;
+};
+
+function vaultContextValuesEqual(
+  prev: AppVaultContextValue,
+  next: AppVaultContextValue,
+): boolean {
+  const keys = Object.keys(next) as Array<keyof AppVaultContextValue>;
+  return keys.every((key) => prev[key] === next[key]);
+}
+
+/**
+ * Owns `useVaultState` and publishes it three ways: the catalog into
+ * `vaultSnapshotStore` for shell surfaces that subscribe to a slice, the
+ * mutators into the same store's action slot, and a **catalog-only** runtime
+ * onto `AppVaultRuntimeContext` for App.
+ *
+ * `notes` / `noteGroups` / `connectionLogs` / `shellHistory` are intentionally
+ * absent from the context value: they churn on a different cadence and already
+ * fan out through dedicated stores. Including them would force App (the
+ * domain-bag builder) to re-render on every note edit or session log append.
+ * Imperative callers that still need the full hook return use
+ * `getAppVaultRuntime()`.
+ */
+export function VaultPublisher({ children }: VaultPublisherProps) {
+  const vault = useVaultState();
+  const {
+    isInitialized,
+    hosts,
+    keys,
+    identities,
+    proxyProfiles,
+    snippets,
+    snippetPackages,
+    customGroups,
+    knownHosts,
+    managedSources,
+    groupConfigs,
+    updateHosts,
+    updateKeys,
+    importOrReuseKey,
+    updateIdentities,
+    updateProxyProfiles,
+    updateSnippets,
+    updateSnippetPackages,
+    updateCustomGroups,
+    updateKnownHosts,
+    updateManagedSources,
+    updateGroupConfigs,
+    convertKnownHostToHost,
+    readPersistedHosts,
+    readPersistedManagedSources,
+    commitPluginImporterData,
+    commitVaultImportTransaction,
+    updateHostDistro,
+    updateHostLastConnected,
+    addShellHistoryEntry,
+    removeShellHistoryEntry,
+  } = vault;
+
+  useLayoutEffect(() => {
+    registerAppVaultRuntime(vault);
+  }, [vault]);
+
+  // Only a real unmount clears the slot. A re-render re-registers through the
+  // effect above, and StrictMode's simulated remount re-runs both.
+  useLayoutEffect(() => () => {
+    registerAppVaultRuntime(null);
+  }, []);
+
+  // useVaultState decrypts hosts/keys before it reads known hosts, so the state
+  // is briefly empty at boot even when storage has entries. Publish the same
+  // storage fallback App uses so a subscriber connecting during that window
+  // does not re-prompt for a fingerprint it already trusts.
+  const effectiveKnownHosts = useMemo(
+    () => getEffectiveKnownHosts(knownHosts) ?? [],
+    [knownHosts],
+  );
+
+  useLayoutEffect(() => {
+    publishVaultSnapshot({
+      isVaultInitialized: isInitialized,
+      hosts,
+      keys,
+      identities,
+      proxyProfiles,
+      snippets,
+      snippetPackages,
+      customGroups,
+      knownHosts: effectiveKnownHosts,
+      managedSources,
+      groupConfigs,
+    });
+  }, [
+    customGroups,
+    effectiveKnownHosts,
+    groupConfigs,
+    hosts,
+    identities,
+    isInitialized,
+    keys,
+    managedSources,
+    proxyProfiles,
+    snippetPackages,
+    snippets,
+  ]);
+
+  useLayoutEffect(() => {
+    registerVaultSnapshotActions({
+      updateHosts,
+      updateKeys,
+      importOrReuseKey,
+      updateIdentities,
+      updateProxyProfiles,
+      updateSnippets,
+      updateSnippetPackages,
+      updateCustomGroups,
+      updateKnownHosts,
+      updateManagedSources,
+      updateGroupConfigs,
+      convertKnownHostToHost,
+      readPersistedHosts,
+      readPersistedManagedSources,
+      commitPluginImporterData,
+      commitVaultImportTransaction,
+      updateHostDistro,
+      updateHostLastConnected,
+      addShellHistoryEntry,
+      removeShellHistoryEntry,
+    });
+    return () => {
+      registerVaultSnapshotActions(null);
+    };
+  }, [
+    addShellHistoryEntry,
+    commitPluginImporterData,
+    commitVaultImportTransaction,
+    convertKnownHostToHost,
+    importOrReuseKey,
+    readPersistedHosts,
+    readPersistedManagedSources,
+    removeShellHistoryEntry,
+    updateCustomGroups,
+    updateGroupConfigs,
+    updateHostDistro,
+    updateHostLastConnected,
+    updateHosts,
+    updateIdentities,
+    updateKeys,
+    updateKnownHosts,
+    updateManagedSources,
+    updateProxyProfiles,
+    updateSnippetPackages,
+    updateSnippets,
+  ]);
+
+  // Strip high-churn fields, then retain the previous object identity when only
+  // those fields (or exportData) changed so React context consumers stay quiet.
+  const vaultForAppRef = useRef<AppVaultContextValue | null>(null);
+  const vaultForApp = useMemo((): AppVaultContextValue => {
+    const {
+      notes: _notes,
+      noteGroups: _noteGroups,
+      connectionLogs: _connectionLogs,
+      shellHistory: _shellHistory,
+      exportData: _exportData,
+      ...catalog
+    } = vault;
+    const prev = vaultForAppRef.current;
+    if (prev && vaultContextValuesEqual(prev, catalog)) {
+      return prev;
+    }
+    vaultForAppRef.current = catalog;
+    return catalog;
+  }, [vault]);
+
+  return (
+    <AppVaultRuntimeContext.Provider value={vaultForApp}>
+      {children}
+    </AppVaultRuntimeContext.Provider>
+  );
+}

application/app/strictModeIdempotency.test.ts

@@ -0,0 +1,271 @@
+import assert from 'node:assert/strict';
+import { readFileSync } from 'node:fs';
+import test from 'node:test';
+
+const appSource = readFileSync(new URL('../../App.tsx', import.meta.url), 'utf8');
+const appSideEffectsSource = readFileSync(
+  new URL('./AppSideEffects.tsx', import.meta.url),
+  'utf8',
+);
+const indexSource = readFileSync(new URL('../../index.tsx', import.meta.url), 'utf8');
+const startupEffectsSource = readFileSync(
+  new URL('./useAppStartupEffects.ts', import.meta.url),
+  'utf8',
+);
+const updateCheckSource = readFileSync(
+  new URL('../state/useUpdateCheck.ts', import.meta.url),
+  'utf8',
+);
+const portForwardingAutoStartSource = readFileSync(
+  new URL('../state/usePortForwardingAutoStart.ts', import.meta.url),
+  'utf8',
+);
+
+test('every renderer root mounts under StrictMode', () => {
+  assert.match(indexSource, /import \{ StrictMode, Suspense, lazy \} from 'react'/);
+
+  const renderCalls = indexSource.match(/root\.render\(/g) ?? [];
+  assert.equal(renderCalls.length, 4, 'main, settings, tray and terminal-popup roots');
+
+  let cursor = 0;
+  for (let index = 0; index < renderCalls.length; index += 1) {
+    const renderAt = indexSource.indexOf('root.render(', cursor);
+    assert.notEqual(renderAt, -1);
+    const opener = indexSource.slice(renderAt, renderAt + 60);
+    assert.match(opener, /root\.render\(\s*<StrictMode>/, `root.render #${index + 1} lacks StrictMode`);
+    cursor = renderAt + 'root.render('.length;
+  }
+});
+
+test('clone-session payload is consumed once even if the effect re-runs', () => {
+  const effectStart = appSideEffectsSource.indexOf('consumedNewWindowSessionRef');
+  assert.notEqual(effectStart, -1, 'clone-session effect must latch on payload identity');
+  const effectEnd = appSideEffectsSource.indexOf(
+    '}, [createSessionFromCloneSource, isVaultInitialized, pendingNewWindowSession]);',
+    effectStart,
+  );
+  assert.notEqual(effectEnd, -1);
+  const body = appSideEffectsSource.slice(effectStart, effectEnd);
+
+  // A ref comparison is required: clearing the state only lands on the next
+  // render, so a re-invoked effect still closes over the same payload.
+  assert.match(body, /if \(consumedNewWindowSessionRef\.current === pendingNewWindowSession\) return;/);
+  assert.ok(
+    body.indexOf('consumedNewWindowSessionRef.current = pending')
+      < body.indexOf('createSessionFromCloneSource(pending.sourceSession'),
+    'payload must be marked consumed before the clone is created',
+  );
+});
+
+test('rendererReady is notified once per renderer process', () => {
+  assert.match(appSource, /^let rendererReadySent = false;$/m);
+  const guardAt = appSource.indexOf('if (!rendererReadySent) {');
+  assert.notEqual(guardAt, -1);
+  const guarded = appSource.slice(guardAt, guardAt + 200);
+  assert.match(guarded, /rendererReadySent = true;/);
+  assert.match(guarded, /netcattyBridge\.get\(\)\?\.rendererReady\?\.\(\)/);
+  assert.ok(
+    guarded.indexOf('rendererReadySent = true;')
+      < guarded.indexOf('netcattyBridge.get()?.rendererReady?.()'),
+    'the latch must be set before the IPC call so a re-entrant effect is blocked',
+  );
+});
+
+test('update-available toast latches on the release version', () => {
+  const latchAt = startupEffectsSource.indexOf('toastedUpdateVersionRef');
+  assert.notEqual(latchAt, -1);
+  assert.match(startupEffectsSource, /const toastedUpdateVersionRef = useRef<string \| null>\(null\)/);
+  assert.match(startupEffectsSource, /if \(toastedUpdateVersionRef\.current === version\) return;/);
+
+  const guardAt = startupEffectsSource.indexOf('if (toastedUpdateVersionRef.current === version) return;');
+  const toastAt = startupEffectsSource.indexOf('toast.info(', guardAt);
+  assert.notEqual(toastAt, -1);
+  assert.ok(guardAt < toastAt, 'the version latch must gate the toast call');
+});
+
+test('port-forward auto-start runs once across a StrictMode double effect', () => {
+  assert.match(
+    portForwardingAutoStartSource,
+    /const autoStartExecutedRef = useRef\(false\);/,
+    'the launch auto-start needs a module-render latch, not just an effect dep list',
+  );
+
+  const effectStart = portForwardingAutoStartSource.indexOf('if (autoStartExecutedRef.current) return;');
+  assert.notEqual(effectStart, -1, 'the effect must bail out when the latch is already set');
+  const effectEnd = portForwardingAutoStartSource.indexOf(
+    '}, [\n    enabled,\n    isVaultInitialized,\n    runAutoStart,\n  ]);',
+    effectStart,
+  );
+  assert.notEqual(effectEnd, -1, 'auto-start effect dep list moved; update this contract');
+  const body = portForwardingAutoStartSource.slice(effectStart, effectEnd);
+
+  // StrictMode invokes the effect twice with the same render's closure, so the
+  // latch has to be written before the async run is kicked off — awaiting or
+  // deferring the write would let the second invoke start a duplicate tunnel.
+  const latchAt = body.indexOf('autoStartExecutedRef.current = true;');
+  const runAt = body.indexOf('void runAutoStart();');
+  assert.notEqual(latchAt, -1);
+  assert.notEqual(runAt, -1);
+  assert.ok(latchAt < runAt, 'the latch must be set before runAutoStart() is called');
+
+  // The vault gate must also sit before the latch: latching on a pre-hydration
+  // invoke would permanently suppress the real auto-start.
+  assert.ok(
+    body.indexOf('if (!isVaultInitialized) return;') < latchAt,
+    'the vault gate must precede the latch write',
+  );
+});
+
+test('cancelled startup update check resets its latch instead of skipping forever', () => {
+  const scheduleAt = updateCheckSource.indexOf('let checkArmed = true;');
+  assert.notEqual(scheduleAt, -1);
+  const tail = updateCheckSource.slice(scheduleAt);
+
+  // The latch is only meaningful once the timer actually fires; a cleanup that
+  // cancels it beforehand must let the next effect schedule again.
+  assert.match(tail, /startupCheckTimeoutRef\.current = setTimeout\(async \(\) => \{\s*\n\s*checkArmed = false;/);
+  assert.match(tail, /if \(checkArmed\) \{\s*\n\s*hasCheckedOnStartupRef\.current = false;\s*\n\s*\}/);
+});
+
+test('terminal popup config survives StrictMode unsubscribe/resubscribe', () => {
+  const preloadSource = readFileSync(new URL('../../electron/preload.cjs', import.meta.url), 'utf8');
+  const apiSource = readFileSync(new URL('../../electron/preload/api.cjs', import.meta.url), 'utf8');
+
+  assert.match(preloadSource, /lastPayload:\s*null/);
+  assert.match(
+    preloadSource,
+    /terminalPopupConfigState\.lastPayload = payload/,
+    'incoming popup config must be retained beyond the one-shot pending slot',
+  );
+
+  const subscribeAt = apiSource.indexOf('onTerminalPopupConfig:');
+  assert.notEqual(subscribeAt, -1);
+  const subscribe = apiSource.slice(subscribeAt, subscribeAt + 700);
+  assert.match(
+    subscribe,
+    /terminalPopupConfigState\.pending \?\? terminalPopupConfigState\.lastPayload/,
+    'resubscribe must replay lastPayload after pending was drained',
+  );
+  assert.match(subscribe, /terminalPopupConfigState\.pending = null/);
+  assert.doesNotMatch(
+    subscribe,
+    /terminalPopupConfigState\.lastPayload = null/,
+    'StrictMode remount must not clear lastPayload on subscribe',
+  );
+});
+
+test('vault init cancels the superseded StrictMode effect before publishing ready', () => {
+  const vaultSource = readFileSync(
+    new URL('../state/useVaultState.ts', import.meta.url),
+    'utf8',
+  );
+  const initAt = vaultSource.indexOf('let cancelled = false;');
+  assert.notEqual(initAt, -1, 'vault init must track cancellation');
+  const initSlice = vaultSource.slice(initAt, initAt + 12000);
+  assert.match(initSlice, /return \(\) => \{\s*\n\s*cancelled = true;\s*\n\s*\};/);
+  assert.match(
+    initSlice,
+    /if \(!cancelled\) \{\s*\n\s*setIsInitialized\(true\);\s*\n\s*setVaultInitialized\(true\);\s*\n\s*\}/,
+    'only the surviving init may mark the vault ready',
+  );
+  assert.match(initSlice, /if \(cancelled\) return;/);
+});
+
+test('global hotkey registration cleans up across StrictMode remount', () => {
+  const systemEffectsSource = readFileSync(
+    new URL('../state/systemSettingsEffects.ts', import.meta.url),
+    'utf8',
+  );
+  const hotkeyAt = systemEffectsSource.indexOf('Persist and sync toggle window hotkey setting');
+  assert.notEqual(hotkeyAt, -1);
+  const hotkeyEffect = systemEffectsSource.slice(hotkeyAt, hotkeyAt + 2200);
+  assert.match(hotkeyEffect, /let cancelled = false;/);
+  assert.match(hotkeyEffect, /if \(cancelled\) return;/);
+  assert.match(
+    hotkeyEffect,
+    /if \(didRegister\) \{\s*\n\s*bridge\?\.unregisterGlobalHotkey/,
+    'cleanup must unregister a registration started by this effect',
+  );
+  // Early return before notify must not skip returning the cleanup function.
+  assert.doesNotMatch(
+    hotkeyEffect,
+    /if \(!persistMountedRef\.current\) return;\s*\n\s*notifySettingsChanged/,
+  );
+});
+
+test('settings persistMountedRef resets on StrictMode cleanup', () => {
+  const settingsSource = readFileSync(
+    new URL('../state/useSettingsState.ts', import.meta.url),
+    'utf8',
+  );
+  const markAt = settingsSource.indexOf('Mark persist effects mounted AFTER all persist useEffects');
+  assert.notEqual(markAt, -1);
+  const markEffect = settingsSource.slice(markAt, markAt + 500);
+  assert.match(markEffect, /persistMountedRef\.current = true;/);
+  assert.match(
+    markEffect,
+    /return \(\) => \{\s*\n\s*persistMountedRef\.current = false;\s*\n\s*\};/,
+    'remount must treat boot as a fresh mount, not a settings change',
+  );
+});
+
+test('tray panel connect flush latches against StrictMode double invoke', () => {
+  const sideEffectsSource = readFileSync(
+    new URL('./AppSideEffects.tsx', import.meta.url),
+    'utf8',
+  );
+  assert.match(sideEffectsSource, /pendingTrayConnectFlushKeyRef/);
+  assert.match(
+    sideEffectsSource,
+    /if \(pendingTrayConnectFlushKeyRef\.current === flushKey\) return;/,
+  );
+});
+
+test('ssh transport idle TTL notify latches against StrictMode double invoke', () => {
+  const settingsSource = readFileSync(
+    new URL('../state/useSettingsState.ts', import.meta.url),
+    'utf8',
+  );
+  assert.match(settingsSource, /lastPushedSshTransportIdleTtlRef/);
+  assert.match(
+    settingsSource,
+    /if \(lastPushedSshTransportIdleTtlRef\.current === sshTransportIdleTtlMs\) return;/,
+  );
+  assert.match(
+    settingsSource,
+    /lastPushedSshTransportIdleTtlRef\.current = sshTransportIdleTtlMs;/,
+  );
+});
+
+test('terminal selection Ask-AI payload is consumed once under StrictMode', () => {
+  const hostSource = readFileSync(
+    new URL('../../components/terminalLayer/TerminalLayerSupport.tsx', import.meta.url),
+    'utf8',
+  );
+  assert.match(hostSource, /consumedTerminalSelectionRequestIds/);
+  assert.doesNotMatch(
+    hostSource,
+    /consumedTerminalSelectionRequestIdRef/,
+    'component refs reset on StrictMode remount; use a module Set',
+  );
+  assert.match(
+    hostSource,
+    /if \(consumedTerminalSelectionRequestIds\.has\(pendingTerminalSelection\.requestId\)\)/,
+  );
+  const latchAt = hostSource.indexOf('markTerminalSelectionRequestConsumed(pendingTerminalSelection.requestId)');
+  const draftAt = hostSource.indexOf('updateDraft(scopeKey, defaultAgentId');
+  assert.ok(latchAt > 0 && draftAt > latchAt, 'must latch before mutating the draft');
+});
+
+test('Codex App Server interaction bridge is app-singleton like MCP approvals', () => {
+  assert.match(appSource, /setupCodexAppServerInteractionBridge/);
+  const panelSource = readFileSync(
+    new URL('../../components/AIChatSidePanel.tsx', import.meta.url),
+    'utf8',
+  );
+  assert.doesNotMatch(
+    panelSource,
+    /setupCodexAppServerInteractionBridge/,
+    'per-panel Codex IPC listeners fan out approvals under retained multi-tab mounts',
+  );
+});

application/app/themeRuntimeBridge.ts

@@ -0,0 +1,52 @@
+/**
+ * Theme runtime actions produced by TerminalHost (`useThemeRuntime`).
+ * AppSideEffects handlers (default/follow theme changes) call through this
+ * bridge instead of co-hosting the hook.
+ */
+
+type Listener = () => void;
+
+export type ThemeRuntimeBridgeActions = {
+  clearThemeIntent: () => void;
+  settleManualThemeIntent: () => void;
+  pickTerminalTheme: (themeId: string) => void;
+  resolveFocusedAppearance: (...args: never[]) => unknown;
+  currentTerminalTheme: unknown;
+  globalAppearance: unknown;
+};
+
+class ThemeRuntimeBridge {
+  private actions: ThemeRuntimeBridgeActions | null = null;
+  private listeners = new Set<Listener>();
+
+  get = (): ThemeRuntimeBridgeActions | null => this.actions;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  set(next: ThemeRuntimeBridgeActions | null): void {
+    if (this.actions === next) return;
+    this.actions = next;
+    for (const listener of this.listeners) listener();
+  }
+}
+
+const bridge = new ThemeRuntimeBridge();
+
+export function registerThemeRuntimeActions(
+  actions: ThemeRuntimeBridgeActions | null,
+): void {
+  bridge.set(actions);
+}
+
+export function getThemeRuntimeActions(): ThemeRuntimeBridgeActions | null {
+  return bridge.get();
+}
+
+export function subscribeThemeRuntimeActions(listener: Listener): () => void {
+  return bridge.subscribe(listener);
+}

application/app/useAppStartupEffects.ts

@@ -213,6 +213,7 @@ export function useAppStartupEffects(ctx: StartupEffectsContext) {
   }, [dedicatedResumeHosts, enabled, identities, isVaultInitialized, keys, knownHosts, terminalSettings]);
 
   // Show toast notification when update is available (only when auto-download is idle)
+  const toastedUpdateVersionRef = useRef<string | null>(null);
   useEffect(() => {
     if (!enabled) return;
     // Skip "update available" toast if auto-download has already started or completed
@@ -221,6 +222,8 @@ export function useAppStartupEffects(ctx: StartupEffectsContext) {
     if (localStorageAdapter.readString('netcatty_auto_update_enabled_v1') === 'false') return;
     if (updateState.hasUpdate && updateState.latestRelease) {
       const version = updateState.latestRelease.version;
+      if (toastedUpdateVersionRef.current === version) return;
+      toastedUpdateVersionRef.current = version;
       toast.info(
         t('update.available.message', { version }),
         {

application/app/useAppThemeStyle.ts

@@ -0,0 +1,28 @@
+import type React from 'react';
+import { useMemo } from 'react';
+
+import { useAppearanceChromeStore } from '../state/appearanceChromeStore';
+import { useSettingsChromeStore } from '../state/settingsChromeStore';
+import { buildAppThemeCssVars } from '../state/settingsStateDefaults';
+import { getUiThemeById } from '../../infrastructure/config/uiThemes';
+
+/**
+ * App theme CSS variables for surfaces that need them (vault surface, plugin
+ * theme tokens). Reads accent from appearanceChromeStore and UI theme ids from
+ * settingsChromeStore so accent drags only re-render the leaf that applies the
+ * vars, never the App shell.
+ */
+export function useAppThemeStyle(): React.CSSProperties {
+  const { accentMode, customAccent } = useAppearanceChromeStore();
+  const { resolvedTheme, darkUiThemeId, lightUiThemeId } = useSettingsChromeStore();
+  return useMemo(() => {
+    const tokens = getUiThemeById(
+      resolvedTheme,
+      resolvedTheme === 'dark' ? darkUiThemeId : lightUiThemeId,
+    ).tokens;
+    return {
+      ...buildAppThemeCssVars(tokens, accentMode, customAccent),
+      colorScheme: resolvedTheme,
+    } as React.CSSProperties;
+  }, [accentMode, customAccent, darkUiThemeId, lightUiThemeId, resolvedTheme]);
+}

application/app/workTabSurface.test.ts

@@ -267,6 +267,32 @@ test('shared host tree uses the followed terminal theme when follow-app terminal
   assert.equal(resolved.id, currentTheme.id);
 });
 
+test('follow-app host tree applies custom accent onto the published base theme', () => {
+  const currentTheme = makeTheme('app-light', 'light', '#ffffff');
+  const host = {
+    id: 'host-1',
+    label: 'Host',
+    hostname: 'host.local',
+    username: 'root',
+    tags: [],
+    os: 'linux',
+  } as Host;
+
+  const resolved = resolveWorkTabHostTreeTheme({
+    activeHostId: host.id,
+    accentMode: 'custom',
+    currentTerminalTheme: currentTheme,
+    customAccent: '0 100% 50%',
+    followAppTerminalTheme: true,
+    hostById: new Map([[host.id, host]]),
+    themeById: new Map([[currentTheme.id, currentTheme]]),
+  });
+
+  assert.equal(resolved.id, currentTheme.id);
+  assert.notEqual(resolved.colors.cursor, currentTheme.colors.cursor);
+  assert.notEqual(resolved, currentTheme);
+});
+
 test('shared host tree falls back to the current terminal theme without an active host', () => {
   const currentTheme = makeTheme('app-dark', 'dark', '#111111');
 

application/app/workTabSurface.ts

@@ -179,7 +179,9 @@ export function resolveWorkTabHostTreeTheme({
   hostById: ReadonlyMap<string, Host>;
   themeById: ReadonlyMap<string, TerminalTheme>;
 }): TerminalTheme {
-  if (!activeHostId || followAppTerminalTheme) return currentTerminalTheme;
+  if (!activeHostId || followAppTerminalTheme) {
+    return applyCustomAccentToTerminalTheme(currentTerminalTheme, accentMode, customAccent);
+  }
 
   const host = hostById.get(activeHostId) ?? null;
   const themeId = resolveHostTerminalThemeId(host, currentTerminalTheme.id);

application/i18n/locales/en/vault.ts

@@ -268,6 +268,8 @@ export const enVaultMessages: Messages = {
   'sftp.transfers.calculatingTotal': 'Calculating total size...',
   'sftp.transfers.filesCount': '{count} files',
   'sftp.transfers.filesProgress': '{current}/{total} files',
+  // Progressive folder walk: total is "found so far", not a fixed grand total.
+  'sftp.transfers.filesDiscoveredProgress': '{completed} done · {discovered} found',
   'sftp.transfers.expandChildren': 'Show files',
   'sftp.transfers.collapseChildren': 'Hide files',
   'sftp.transfers.expandChildList': 'Show detail',
@@ -560,6 +562,9 @@ export const enVaultMessages: Messages = {
   'settings.sftp.compressedUpload.enable': 'Enable folder compression',
   'settings.sftp.compressedUpload.enableDesc': 'Automatically compress folders using tar before transfer. Requires tar support on the server. Falls back to regular transfer if not available.',
 
+  'settings.sftp.skipUnchanged.enable': 'Skip unchanged files',
+  'settings.sftp.skipUnchanged.enableDesc': 'Skip files whose size and modification time already match the destination (rsync-style). Disabled when replacing a folder into a staging path.',
+
   // Quick Switcher
   'qs.search.placeholder': 'Search hosts or tabs',
   'qs.jumpTo': 'Jump To',

application/i18n/locales/ru/vault.ts

@@ -305,6 +305,7 @@ export const ruVaultMessages: Messages = {
   'sftp.transfers.calculatingTotal': 'Вычисление общего размера...',
   'sftp.transfers.filesCount': '{count} файл(ов)',
   'sftp.transfers.filesProgress': '{current}/{total} файл(ов)',
+  'sftp.transfers.filesDiscoveredProgress': '{completed} готово · {discovered} найдено',
   'sftp.transfers.expandChildren': 'Показать файлы',
   'sftp.transfers.collapseChildren': 'Скрыть файлы',
   'sftp.transfers.expandChildList': 'Показать детали',
@@ -597,6 +598,9 @@ export const ruVaultMessages: Messages = {
   'settings.sftp.compressedUpload.enable': 'Включить сжатие папок',
   'settings.sftp.compressedUpload.enableDesc': 'Автоматически сжимать папки с помощью tar перед передачей. Требует поддержки tar на сервере. Если она недоступна, будет использована обычная передача.',
 
+  'settings.sftp.skipUnchanged.enable': 'Пропускать неизменённые файлы',
+  'settings.sftp.skipUnchanged.enableDesc': 'Пропускать файлы, у которых размер и время изменения уже совпадают с назначением (в стиле rsync). Отключается при замене папки во временный путь.',
+
   // Quick Switcher
   'qs.search.placeholder': 'Поиск хостов или вкладок',
   'qs.jumpTo': 'Перейти к',

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

@@ -863,6 +863,7 @@ export const zhCNCoreMessages: Messages = {
   'sftp.transfers.calculatingTotal': '正在统计总大小...',
   'sftp.transfers.filesCount': '{count} 个文件',
   'sftp.transfers.filesProgress': '{current}/{total} 个文件',
+  'sftp.transfers.filesDiscoveredProgress': '已完成 {completed} · 已发现 {discovered}',
   'sftp.transfers.expandChildren': '展开文件',
   'sftp.transfers.collapseChildren': '收起文件',
   'sftp.transfers.expandChildList': '展开详情',

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

@@ -206,6 +206,9 @@ export const zhCNTerminalMessages: Messages = {
   'settings.sftp.compressedUpload.enable': '启用文件夹压缩',
   'settings.sftp.compressedUpload.enableDesc': '自动使用 tar 压缩文件夹后再传输。需要服务器支持 tar 命令，不支持时自动回退到普通传输。',
 
+  'settings.sftp.skipUnchanged.enable': '跳过未改文件',
+  'settings.sftp.skipUnchanged.enableDesc': '当目标文件的大小与修改时间已与源一致时跳过传输（类似 rsync）。替换到暂存路径时自动禁用。',
+
   // Settings > Terminal
   'settings.terminal.section.theme': '终端主题',
   'settings.terminal.themeModal.title': '选择主题',

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

@@ -863,6 +863,7 @@ export const zhTWCoreMessages: Messages = {
   'sftp.transfers.calculatingTotal': '正在統計總大小...',
   'sftp.transfers.filesCount': '{count} 個檔案',
   'sftp.transfers.filesProgress': '{current}/{total} 個檔案',
+  'sftp.transfers.filesDiscoveredProgress': '已完成 {completed} · 已發現 {discovered}',
   'sftp.transfers.expandChildren': '展開檔案',
   'sftp.transfers.collapseChildren': '收起檔案',
   'sftp.transfers.expandChildList': '展開詳情',

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

@@ -206,6 +206,9 @@ export const zhTWTerminalMessages: Messages = {
   'settings.sftp.compressedUpload.enable': '啟用資料夾壓縮',
   'settings.sftp.compressedUpload.enableDesc': '自動使用 tar 壓縮資料夾後再傳輸。需要伺服器支援 tar 指令，不支援時自動回退到普通傳輸。',
 
+  'settings.sftp.skipUnchanged.enable': '跳過未改檔案',
+  'settings.sftp.skipUnchanged.enableDesc': '當目標檔案的大小與修改時間已與來源一致時跳過傳輸（類似 rsync）。替換到暫存路徑時自動停用。',
+
   // Settings > Terminal
   'settings.terminal.section.theme': '終端主題',
   'settings.terminal.themeModal.title': '選擇主題',

application/state/activeChromeThemeSync.test.ts

@@ -7,7 +7,7 @@ const chromeThemeSource = readFileSync(new URL("./useActiveChromeTheme.ts", impo
 const storeSource = readFileSync(new URL("./activeTabStore.ts", import.meta.url), "utf8");
 
 test("active tab changes notify chrome theme before react subscribers", () => {
-  const setActiveTabIdBody = storeSource.match(/setActiveTabId = \(id: string\) => \{[\s\S]*?\n {2}\};/)?.[0] ?? "";
+  const setActiveTabIdBody = storeSource.match(/setActiveTabId = \(id: string(?:, options\?: \w+)?\) => \{[\s\S]*?\n {2}\};/)?.[0] ?? "";
   assert.match(setActiveTabIdBody, /this\.syncListeners\.forEach\(\(listener\) => listener\(id\)\)/);
   assert.match(setActiveTabIdBody, /this\.scheduleNotify\(\)/);
   assert.ok(

application/state/activeTabStore.test.ts

@@ -4,6 +4,37 @@ import test from 'node:test';
 import { activeTabStore, fromEditorTabId, isEditorTabId, toEditorTabId } from './activeTabStore';
 import { terminalLayoutSuppressStore } from './terminalLayoutSuppressStore';
 
+test('active tab store remembers the previous tab for restore-on-close', () => {
+  const previousWindow = (globalThis as { window?: unknown }).window;
+  (globalThis as { window?: unknown }).window ??= globalThis;
+
+  const marker = `prev-tab-${Date.now()}`;
+  const first = `${marker}-a`;
+  const second = `${marker}-b`;
+  const third = `${marker}-c`;
+  const before = activeTabStore.getActiveTabId();
+
+  try {
+    activeTabStore.setActiveTabId(first);
+    activeTabStore.setActiveTabId(second);
+    assert.equal(activeTabStore.getPreviousActiveTabId(), first);
+
+    activeTabStore.setActiveTabId(third);
+    assert.equal(activeTabStore.getPreviousActiveTabId(), second);
+
+    activeTabStore.setActiveTabId(first, { recordPrevious: false });
+    assert.equal(activeTabStore.getActiveTabId(), first);
+    assert.equal(activeTabStore.getPreviousActiveTabId(), second);
+  } finally {
+    activeTabStore.setActiveTabId(before, { recordPrevious: false });
+    if (previousWindow === undefined) {
+      delete (globalThis as { window?: unknown }).window;
+    } else {
+      (globalThis as { window?: unknown }).window = previousWindow;
+    }
+  }
+});
+
 test('editor tab helpers round trip ids', () => {
   assert.equal(toEditorTabId('file-1'), 'editor:file-1');
   assert.equal(fromEditorTabId('editor:file-1'), 'file-1');

application/state/activeTabStore.ts

@@ -16,14 +16,22 @@ export const toEditorTabId = (editorId: string): string => `${EDITOR_PREFIX}${ed
 /** Strip the "editor:" prefix to recover the internal editorTab id. */
 export const fromEditorTabId = (tabId: string): string => tabId.slice(EDITOR_PREFIX.length);
 
+type SetActiveTabOptions = {
+  /** When false, keep the previous-tab pointer unchanged (used for close restore). */
+  recordPrevious?: boolean;
+};
+
 class ActiveTabStore {
   private activeTabId: string = 'vault';
+  private previousActiveTabId: string | null = null;
   private listeners = new Set<Listener>();
   private syncListeners = new Set<SyncListener>();
   private notifyRafId: number | null = null;
 
   getActiveTabId = () => this.activeTabId;
 
+  getPreviousActiveTabId = () => this.previousActiveTabId;
+
   private scheduleNotify = () => {
     if (this.notifyRafId !== null) return;
     const schedule = typeof requestAnimationFrame === 'function'
@@ -35,8 +43,11 @@ class ActiveTabStore {
     });
   };
 
-  setActiveTabId = (id: string) => {
+  setActiveTabId = (id: string, options?: SetActiveTabOptions) => {
     if (this.activeTabId !== id) {
+      if (options?.recordPrevious !== false) {
+        this.previousActiveTabId = this.activeTabId;
+      }
       this.activeTabId = id;
       this.syncListeners.forEach((listener) => listener(id));
       // Coalesce rapid tab switches into one notification per frame and avoid

application/state/aiPanelDiagnostics.ts

@@ -0,0 +1,85 @@
+import type React from 'react';
+import {
+  STORAGE_KEY_AI_PANEL_DIAGNOSTIC_HIDE,
+  STORAGE_KEY_AI_PANEL_DIAGNOSTIC_PROFILE,
+} from '../../infrastructure/config/storageKeys';
+import { localStorageAdapter } from '../../infrastructure/persistence/localStorageAdapter';
+
+export const AI_PANEL_DIAGNOSTIC_HIDE_KEY = STORAGE_KEY_AI_PANEL_DIAGNOSTIC_HIDE;
+export const AI_PANEL_DIAGNOSTIC_PROFILE_KEY = STORAGE_KEY_AI_PANEL_DIAGNOSTIC_PROFILE;
+export const AI_PANEL_FORCE_HIDE_ALL_CONTENT = false;
+export const AI_PANEL_FORCE_HIDE_SHELL = false;
+
+export type AIPanelDiagnosticPart =
+  | 'all'
+  | 'attachments'
+  | 'header'
+  | 'history'
+  | 'input'
+  | 'markdown'
+  | 'messages'
+  | 'recent'
+  | 'toolcalls';
+
+function readLocalStorageValue(key: string): string {
+  try {
+    return localStorageAdapter.readString(key) ?? '';
+  } catch {
+    return '';
+  }
+}
+
+export function getAIPanelDiagnosticHiddenParts(): ReadonlySet<string> {
+  if (AI_PANEL_FORCE_HIDE_ALL_CONTENT) {
+    return new Set(['all']);
+  }
+  const raw = readLocalStorageValue(AI_PANEL_DIAGNOSTIC_HIDE_KEY);
+  return new Set(
+    raw
+      .split(',')
+      .map((part) => part.trim().toLowerCase())
+      .filter(Boolean),
+  );
+}
+
+export function isAIPanelDiagnosticPartHidden(
+  part: AIPanelDiagnosticPart,
+  hiddenParts = getAIPanelDiagnosticHiddenParts(),
+): boolean {
+  return hiddenParts.has('all') || hiddenParts.has(part);
+}
+
+export function isAIPanelDiagnosticsProfilingEnabled(): boolean {
+  const raw = readLocalStorageValue(AI_PANEL_DIAGNOSTIC_PROFILE_KEY).trim().toLowerCase();
+  return raw === '1' || raw === 'true' || raw === 'yes' || raw === 'on';
+}
+
+export function logAIPanelProfiler(
+  id: string,
+  phase: 'mount' | 'update' | 'nested-update',
+  actualDuration: number,
+  baseDuration: number,
+): void {
+  if (!isAIPanelDiagnosticsProfilingEnabled()) return;
+  console.info(
+    `[AI panel profile] ${id} ${phase}: actual=${actualDuration.toFixed(1)}ms base=${baseDuration.toFixed(1)}ms`,
+  );
+}
+
+export function profileAIPanelCalculation<T>(label: string, calculate: () => T): T {
+  if (!isAIPanelDiagnosticsProfilingEnabled()) return calculate();
+  const startedAt = performance.now();
+  try {
+    return calculate();
+  } finally {
+    const elapsed = performance.now() - startedAt;
+    console.info(`[AI panel profile] ${label}: ${elapsed.toFixed(1)}ms`);
+  }
+}
+
+export function getAIPanelProfilerProps(id: string): Pick<React.ProfilerProps, 'id' | 'onRender'> {
+  return {
+    id,
+    onRender: logAIPanelProfiler,
+  };
+}

application/state/aiSessionsStore.ts

@@ -0,0 +1,80 @@
+import { useSyncExternalStore } from 'react';
+
+import type { AISession } from '../../infrastructure/ai/types';
+import type { DraftsByScope, PanelViewByScope } from './aiStateSnapshots';
+
+type Listener = () => void;
+
+export type AISessionsSnapshot = {
+  sessions: readonly AISession[];
+  activeSessionIdMap: Readonly<Record<string, string | null>>;
+  draftsByScope: DraftsByScope;
+  panelViewByScope: PanelViewByScope;
+};
+
+const EMPTY_SESSIONS: readonly AISession[] = Object.freeze([]);
+const EMPTY_MAP: Readonly<Record<string, string | null>> = Object.freeze({});
+const EMPTY_DRAFTS: DraftsByScope = Object.freeze({});
+const EMPTY_PANEL: PanelViewByScope = Object.freeze({});
+
+export const EMPTY_AI_SESSIONS_SNAPSHOT: AISessionsSnapshot = Object.freeze({
+  sessions: EMPTY_SESSIONS,
+  activeSessionIdMap: EMPTY_MAP,
+  draftsByScope: EMPTY_DRAFTS,
+  panelViewByScope: EMPTY_PANEL,
+});
+
+/**
+ * Hot AI chat state — streaming message updates must not invalidate
+ * slow AI config Context consumers (providers, permissions, etc.).
+ */
+class AISessionsStore {
+  private snapshot: AISessionsSnapshot = EMPTY_AI_SESSIONS_SNAPSHOT;
+  private listeners = new Set<Listener>();
+
+  getSnapshot = (): AISessionsSnapshot => this.snapshot;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  setSnapshot(next: AISessionsSnapshot): void {
+    if (
+      this.snapshot.sessions === next.sessions
+      && this.snapshot.activeSessionIdMap === next.activeSessionIdMap
+      && this.snapshot.draftsByScope === next.draftsByScope
+      && this.snapshot.panelViewByScope === next.panelViewByScope
+    ) {
+      return;
+    }
+    this.snapshot = next;
+    for (const listener of this.listeners) {
+      listener();
+    }
+  }
+}
+
+export const aiSessionsStore = new AISessionsStore();
+
+export function publishAISessionsSnapshot(snapshot: AISessionsSnapshot): void {
+  aiSessionsStore.setSnapshot(snapshot);
+}
+
+export function getAISessionsSnapshot(): AISessionsSnapshot {
+  return aiSessionsStore.getSnapshot();
+}
+
+export function subscribeAISessions(listener: Listener): () => void {
+  return aiSessionsStore.subscribe(listener);
+}
+
+export function useAISessionsStore(): AISessionsSnapshot {
+  return useSyncExternalStore(
+    subscribeAISessions,
+    getAISessionsSnapshot,
+    getAISessionsSnapshot,
+  );
+}

application/state/appRuntimeBridge.test.ts

@@ -0,0 +1,99 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import {
+  getAppSessionRuntime,
+  getAppSettingsRuntime,
+  getAppVaultRuntime,
+  registerAppSessionRuntime,
+  registerAppSettingsRuntime,
+  registerAppVaultRuntime,
+  subscribeAppSessionRuntime,
+  subscribeAppSettingsRuntime,
+  subscribeAppVaultRuntime,
+  type AppSessionRuntime,
+  type AppSettingsRuntime,
+  type AppVaultRuntime,
+} from './appRuntimeBridge';
+
+const vaultRuntime = (label: string) => ({ label }) as unknown as AppVaultRuntime;
+const sessionRuntime = (label: string) => ({ label }) as unknown as AppSessionRuntime;
+const settingsRuntime = (label: string) => ({ label }) as unknown as AppSettingsRuntime;
+
+test('vault slot exposes the last registered runtime and notifies on change', () => {
+  let notifications = 0;
+  const unsubscribe = subscribeAppVaultRuntime(() => {
+    notifications += 1;
+  });
+
+  const first = vaultRuntime('first');
+  registerAppVaultRuntime(first);
+  assert.equal(getAppVaultRuntime(), first);
+  assert.equal(notifications, 1);
+
+  // Re-registering the same identity is what a render with unchanged state
+  // does; it must not wake subscribers.
+  registerAppVaultRuntime(first);
+  assert.equal(notifications, 1);
+
+  const second = vaultRuntime('second');
+  registerAppVaultRuntime(second);
+  assert.equal(getAppVaultRuntime(), second);
+  assert.equal(notifications, 2);
+
+  unsubscribe();
+  registerAppVaultRuntime(null);
+  assert.equal(getAppVaultRuntime(), null);
+  assert.equal(notifications, 2, 'unsubscribed listeners stay quiet');
+});
+
+test('session slot is independent from the vault slot', () => {
+  let vaultNotifications = 0;
+  let sessionNotifications = 0;
+  const unsubscribeVault = subscribeAppVaultRuntime(() => {
+    vaultNotifications += 1;
+  });
+  const unsubscribeSession = subscribeAppSessionRuntime(() => {
+    sessionNotifications += 1;
+  });
+
+  const runtime = sessionRuntime('session');
+  registerAppSessionRuntime(runtime);
+  assert.equal(getAppSessionRuntime(), runtime);
+  assert.equal(sessionNotifications, 1);
+  assert.equal(vaultNotifications, 0);
+
+  unsubscribeVault();
+  unsubscribeSession();
+  registerAppSessionRuntime(null);
+});
+
+test('settings slot is independent from the vault and session slots', () => {
+  let settingsNotifications = 0;
+  let otherNotifications = 0;
+  const unsubscribeSettings = subscribeAppSettingsRuntime(() => {
+    settingsNotifications += 1;
+  });
+  const unsubscribeVault = subscribeAppVaultRuntime(() => {
+    otherNotifications += 1;
+  });
+  const unsubscribeSession = subscribeAppSessionRuntime(() => {
+    otherNotifications += 1;
+  });
+
+  const runtime = settingsRuntime('settings');
+  registerAppSettingsRuntime(runtime);
+  assert.equal(getAppSettingsRuntime(), runtime);
+  assert.equal(settingsNotifications, 1);
+  assert.equal(otherNotifications, 0);
+
+  // A re-render with unchanged state re-registers the same identity.
+  registerAppSettingsRuntime(runtime);
+  assert.equal(settingsNotifications, 1);
+
+  unsubscribeSettings();
+  unsubscribeVault();
+  unsubscribeSession();
+  registerAppSettingsRuntime(null);
+  assert.equal(getAppSettingsRuntime(), null);
+});

application/state/appRuntimeBridge.ts

@@ -0,0 +1,138 @@
+import { createContext, useContext } from 'react';
+
+import type { useSessionState } from './useSessionState';
+import type { useSettingsState } from './useSettingsState';
+import type { useVaultState } from './useVaultState';
+
+export type AppVaultRuntime = ReturnType<typeof useVaultState>;
+export type AppSessionRuntime = ReturnType<typeof useSessionState>;
+export type AppSettingsRuntime = ReturnType<typeof useSettingsState>;
+
+/**
+ * The slice of the vault runtime that `VaultPublisher` puts on the React
+ * context.
+ *
+ * `notes` / `noteGroups` / `connectionLogs` / `shellHistory` are deliberately
+ * absent. They churn on every note keystroke, session start/exit, and history
+ * append, and publishing them here would re-render every context consumer for
+ * data those consumers only ever read at call time. Consumers subscribe to
+ * `notesStore` / `connectionLogsStore` / `shellHistoryStore` instead, or read
+ * the full runtime imperatively through `getAppVaultRuntime()`.
+ *
+ * `exportData` is omitted for the same reason: its callback identity tracks the
+ * notes arrays, so keeping it would reintroduce the churn it is meant to avoid.
+ */
+export type AppVaultContextValue = Omit<
+  AppVaultRuntime,
+  'notes' | 'noteGroups' | 'connectionLogs' | 'shellHistory' | 'exportData'
+>;
+
+type Listener = () => void;
+
+/**
+ * Holds the live return of one mega hook so the component that owns the hook
+ * and the components that consume it no longer have to be the same component.
+ *
+ * `VaultPublisher` / `SessionPublisher` / `SettingsPublisher` own
+ * `useVaultState` / `useSessionState` / `useSettingsState` and expose the value
+ * two ways:
+ *
+ * - through a React context, for render-time consumers (App). Context keeps the
+ *   read synchronous and non-null from the first render, which a store written
+ *   in a layout effect cannot do for a descendant.
+ * - through this module slot, for imperative callers that need the current
+ *   runtime outside of a render (`getAppVaultRuntime()` in an event handler or
+ *   a bridge callback) and for non-descendant subscribers.
+ */
+class RuntimeSlot<T> {
+  private value: T | null = null;
+  private listeners = new Set<Listener>();
+
+  get = (): T | null => this.value;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  set(next: T | null): void {
+    if (this.value === next) return;
+    this.value = next;
+    for (const listener of this.listeners) {
+      listener();
+    }
+  }
+}
+
+const vaultSlot = new RuntimeSlot<AppVaultRuntime>();
+const sessionSlot = new RuntimeSlot<AppSessionRuntime>();
+const settingsSlot = new RuntimeSlot<AppSettingsRuntime>();
+
+export function registerAppVaultRuntime(runtime: AppVaultRuntime | null): void {
+  vaultSlot.set(runtime);
+}
+
+export function getAppVaultRuntime(): AppVaultRuntime | null {
+  return vaultSlot.get();
+}
+
+export function subscribeAppVaultRuntime(listener: Listener): () => void {
+  return vaultSlot.subscribe(listener);
+}
+
+export function registerAppSessionRuntime(runtime: AppSessionRuntime | null): void {
+  sessionSlot.set(runtime);
+}
+
+export function getAppSessionRuntime(): AppSessionRuntime | null {
+  return sessionSlot.get();
+}
+
+export function subscribeAppSessionRuntime(listener: Listener): () => void {
+  return sessionSlot.subscribe(listener);
+}
+
+export function registerAppSettingsRuntime(runtime: AppSettingsRuntime | null): void {
+  settingsSlot.set(runtime);
+}
+
+export function getAppSettingsRuntime(): AppSettingsRuntime | null {
+  return settingsSlot.get();
+}
+
+export function subscribeAppSettingsRuntime(listener: Listener): () => void {
+  return settingsSlot.subscribe(listener);
+}
+
+export const AppVaultRuntimeContext = createContext<AppVaultContextValue | null>(null);
+export const AppSessionRuntimeContext = createContext<AppSessionRuntime | null>(null);
+export const AppSettingsRuntimeContext = createContext<AppSettingsRuntime | null>(null);
+
+/** Read the vault runtime owned by `VaultPublisher`. */
+export function useAppVaultRuntime(): AppVaultContextValue {
+  const runtime = useContext(AppVaultRuntimeContext);
+  if (!runtime) {
+    throw new Error('useAppVaultRuntime must be rendered inside <VaultPublisher>');
+  }
+  return runtime;
+}
+
+/** Read the session runtime owned by `SessionPublisher`. */
+export function useAppSessionRuntime(): AppSessionRuntime {
+  const runtime = useContext(AppSessionRuntimeContext);
+  if (!runtime) {
+    throw new Error('useAppSessionRuntime must be rendered inside <SessionPublisher>');
+  }
+  return runtime;
+}
+
+/** Read the settings runtime owned by `SettingsPublisher`. */
+export function useAppSettingsRuntime(): AppSettingsRuntime {
+  const runtime = useContext(AppSettingsRuntimeContext);
+  if (!runtime) {
+    throw new Error('useAppSettingsRuntime must be rendered inside <SettingsPublisher>');
+  }
+  return runtime;
+}

application/state/appearanceChromeStore.test.ts

@@ -0,0 +1,31 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import {
+  getAppearanceChromeSnapshot,
+  publishAppearanceChromeSnapshot,
+  subscribeAppearanceChrome,
+} from './appearanceChromeStore.ts';
+
+test('appearanceChromeStore notifies subscribers only when accent fields change', () => {
+  const events: string[] = [];
+  const unsubscribe = subscribeAppearanceChrome(() => {
+    const snap = getAppearanceChromeSnapshot();
+    events.push(`${snap.accentMode}:${snap.customAccent}`);
+  });
+
+  publishAppearanceChromeSnapshot({ accentMode: 'custom', customAccent: '#ff0000' });
+  assert.equal(events.at(-1), 'custom:#ff0000');
+  assert.equal(getAppearanceChromeSnapshot().customAccent, '#ff0000');
+
+  publishAppearanceChromeSnapshot({ accentMode: 'custom', customAccent: '#ff0000' });
+  assert.equal(events.length, 1);
+
+  publishAppearanceChromeSnapshot({ accentMode: 'custom', customAccent: '#00ff00' });
+  assert.equal(events.at(-1), 'custom:#00ff00');
+
+  publishAppearanceChromeSnapshot({ accentMode: 'theme', customAccent: '#00ff00' });
+  assert.equal(events.at(-1), 'theme:#00ff00');
+
+  unsubscribe();
+});

application/state/appearanceChromeStore.ts

@@ -0,0 +1,68 @@
+import { useSyncExternalStore } from 'react';
+
+type Listener = () => void;
+
+export type AppearanceChromeSnapshot = {
+  accentMode: 'theme' | 'custom';
+  customAccent: string;
+};
+
+const DEFAULT_SNAPSHOT: AppearanceChromeSnapshot = Object.freeze({
+  accentMode: 'theme',
+  customAccent: '',
+});
+
+/**
+ * External store for app accent chrome so Terminal leaves can apply custom
+ * accent without TerminalLayer rebuilding on every color-picker drag tick.
+ */
+class AppearanceChromeStore {
+  private snapshot: AppearanceChromeSnapshot = DEFAULT_SNAPSHOT;
+  private listeners = new Set<Listener>();
+
+  getSnapshot = (): AppearanceChromeSnapshot => this.snapshot;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  setSnapshot(next: AppearanceChromeSnapshot): void {
+    if (
+      this.snapshot.accentMode === next.accentMode
+      && this.snapshot.customAccent === next.customAccent
+    ) {
+      return;
+    }
+    this.snapshot = next;
+    for (const listener of this.listeners) {
+      listener();
+    }
+  }
+}
+
+export const appearanceChromeStore = new AppearanceChromeStore();
+
+export function publishAppearanceChromeSnapshot(
+  snapshot: AppearanceChromeSnapshot,
+): void {
+  appearanceChromeStore.setSnapshot(snapshot);
+}
+
+export function getAppearanceChromeSnapshot(): AppearanceChromeSnapshot {
+  return appearanceChromeStore.getSnapshot();
+}
+
+export function subscribeAppearanceChrome(listener: Listener): () => void {
+  return appearanceChromeStore.subscribe(listener);
+}
+
+export function useAppearanceChromeStore(): AppearanceChromeSnapshot {
+  return useSyncExternalStore(
+    subscribeAppearanceChrome,
+    getAppearanceChromeSnapshot,
+    getAppearanceChromeSnapshot,
+  );
+}

application/state/connectionLogsStore.test.ts

@@ -0,0 +1,126 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import type { ConnectionLog } from '../../domain/models.ts';
+import {
+  EMPTY_CONNECTION_LOGS_SNAPSHOT,
+  getConnectionLogsActions,
+  getConnectionLogsSnapshot,
+  getEmptyConnectionLogsSnapshot,
+  publishConnectionLogsSnapshot,
+  registerConnectionLogsActions,
+  subscribeConnectionLogs,
+  subscribeConnectionLogsActions,
+} from './connectionLogsStore.ts';
+
+const baseLog: ConnectionLog = {
+  id: 'log-1',
+  sessionId: 'session-1',
+  hostId: 'host-1',
+  hostLabel: 'Example',
+  hostname: 'example.com',
+  username: 'user',
+  protocol: 'ssh',
+  startTime: 1000,
+  localUsername: 'local',
+  localHostname: 'machine',
+  saved: false,
+};
+
+test('connectionLogsStore notifies subscribers only when the log array identity changes', () => {
+  const events: number[] = [];
+  const unsubscribe = subscribeConnectionLogs(() => {
+    events.push(getConnectionLogsSnapshot().connectionLogs.length);
+  });
+
+  const firstLogs = [baseLog];
+  publishConnectionLogsSnapshot({ connectionLogs: firstLogs });
+  assert.equal(events.at(-1), 1);
+  assert.equal(getConnectionLogsSnapshot().connectionLogs, firstLogs);
+
+  // Same identity must not wake the Vault logs section on unrelated renders.
+  publishConnectionLogsSnapshot({ connectionLogs: firstLogs });
+  assert.equal(events.length, 1);
+
+  const secondLogs = [baseLog, { ...baseLog, id: 'log-2', startTime: 2000 }];
+  publishConnectionLogsSnapshot({ connectionLogs: secondLogs });
+  assert.equal(events.at(-1), 2);
+  assert.equal(events.length, 2);
+
+  unsubscribe();
+  publishConnectionLogsSnapshot({ connectionLogs: [] });
+  assert.equal(events.length, 2);
+});
+
+test('connectionLogsStore exposes a frozen empty snapshot for gated mounts', () => {
+  assert.equal(getEmptyConnectionLogsSnapshot(), EMPTY_CONNECTION_LOGS_SNAPSHOT);
+  assert.equal(getEmptyConnectionLogsSnapshot().connectionLogs.length, 0);
+  assert.equal(Object.isFrozen(EMPTY_CONNECTION_LOGS_SNAPSHOT), true);
+});
+
+test('registerConnectionLogsActions exposes the vault log mutators', () => {
+  const calls: string[] = [];
+  const actionEvents: number[] = [];
+  const unsubscribe = subscribeConnectionLogsActions(() => {
+    actionEvents.push(actionEvents.length);
+  });
+
+  registerConnectionLogsActions({
+    updateConnectionLog: () => {
+      calls.push('update');
+    },
+    toggleConnectionLogSaved: () => {
+      calls.push('toggle');
+    },
+    deleteConnectionLog: () => {
+      calls.push('delete');
+    },
+    clearUnsavedConnectionLogs: () => {
+      calls.push('clear');
+    },
+  });
+
+  const actions = getConnectionLogsActions();
+  assert.ok(actions);
+  actions.updateConnectionLog('log-1', { saved: true });
+  actions.toggleConnectionLogSaved('log-1');
+  actions.deleteConnectionLog('log-1');
+  actions.clearUnsavedConnectionLogs();
+  assert.deepEqual(calls, ['update', 'toggle', 'delete', 'clear']);
+  assert.equal(actionEvents.length, 1);
+
+  registerConnectionLogsActions(null);
+  assert.equal(getConnectionLogsActions(), null);
+  assert.equal(actionEvents.length, 2);
+
+  unsubscribe();
+});
+
+test('connectionLogsStore keeps values and actions on independent slots', () => {
+  const valueEvents: number[] = [];
+  const actionEvents: number[] = [];
+  const unsubValues = subscribeConnectionLogs(() => {
+    valueEvents.push(valueEvents.length);
+  });
+  const unsubActions = subscribeConnectionLogsActions(() => {
+    actionEvents.push(actionEvents.length);
+  });
+
+  // Re-registering unstable mutator identities must not invalidate the logs.
+  registerConnectionLogsActions({
+    updateConnectionLog: () => {},
+    toggleConnectionLogSaved: () => {},
+    deleteConnectionLog: () => {},
+    clearUnsavedConnectionLogs: () => {},
+  });
+  assert.equal(valueEvents.length, 0);
+  assert.equal(actionEvents.length, 1);
+
+  publishConnectionLogsSnapshot({ connectionLogs: [baseLog] });
+  assert.equal(valueEvents.length, 1);
+  assert.equal(actionEvents.length, 1);
+
+  registerConnectionLogsActions(null);
+  unsubValues();
+  unsubActions();
+});

application/state/connectionLogsStore.ts

@@ -0,0 +1,135 @@
+import { useSyncExternalStore } from 'react';
+
+import type { ConnectionLog } from '../../domain/models';
+
+type Listener = () => void;
+
+export type ConnectionLogsSnapshot = {
+  connectionLogs: readonly ConnectionLog[];
+};
+
+export type ConnectionLogsActions = {
+  updateConnectionLog: (id: string, updates: Partial<ConnectionLog>) => void;
+  toggleConnectionLogSaved: (id: string) => void;
+  deleteConnectionLog: (id: string) => void;
+  clearUnsavedConnectionLogs: () => void;
+};
+
+const EMPTY_CONNECTION_LOGS: readonly ConnectionLog[] = Object.freeze([]);
+
+export const EMPTY_CONNECTION_LOGS_SNAPSHOT: ConnectionLogsSnapshot = Object.freeze({
+  connectionLogs: EMPTY_CONNECTION_LOGS,
+});
+
+/**
+ * External store for connection logs so the Vault logs section and log-view
+ * replays can subscribe without keeping logs in the App domain bags. Every
+ * session start/exit appends a log, which would otherwise rebuild the whole
+ * shell.
+ */
+class ConnectionLogsStore {
+  private snapshot: ConnectionLogsSnapshot = EMPTY_CONNECTION_LOGS_SNAPSHOT;
+  private actions: ConnectionLogsActions | null = null;
+  private listeners = new Set<Listener>();
+  private actionListeners = new Set<Listener>();
+
+  getSnapshot = (): ConnectionLogsSnapshot => this.snapshot;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  setSnapshot(next: ConnectionLogsSnapshot): void {
+    if (this.snapshot.connectionLogs === next.connectionLogs) return;
+    this.snapshot = next;
+    for (const listener of this.listeners) {
+      listener();
+    }
+  }
+
+  getActions = (): ConnectionLogsActions | null => this.actions;
+
+  subscribeActions = (listener: Listener): (() => void) => {
+    this.actionListeners.add(listener);
+    return () => {
+      this.actionListeners.delete(listener);
+    };
+  };
+
+  setActions(next: ConnectionLogsActions | null): void {
+    if (this.actions === next) return;
+    this.actions = next;
+    for (const listener of this.actionListeners) {
+      listener();
+    }
+  }
+}
+
+export const connectionLogsStore = new ConnectionLogsStore();
+
+export function publishConnectionLogsSnapshot(
+  snapshot: ConnectionLogsSnapshot,
+): void {
+  connectionLogsStore.setSnapshot(snapshot);
+}
+
+export function getConnectionLogsSnapshot(): ConnectionLogsSnapshot {
+  return connectionLogsStore.getSnapshot();
+}
+
+export function subscribeConnectionLogs(listener: Listener): () => void {
+  return connectionLogsStore.subscribe(listener);
+}
+
+export function getEmptyConnectionLogsSnapshot(): ConnectionLogsSnapshot {
+  return EMPTY_CONNECTION_LOGS_SNAPSHOT;
+}
+
+export function registerConnectionLogsActions(
+  actions: ConnectionLogsActions | null,
+): void {
+  connectionLogsStore.setActions(actions);
+}
+
+export function getConnectionLogsActions(): ConnectionLogsActions | null {
+  return connectionLogsStore.getActions();
+}
+
+export function subscribeConnectionLogsActions(listener: Listener): () => void {
+  return connectionLogsStore.subscribeActions(listener);
+}
+
+const noopUpdateConnectionLog: ConnectionLogsActions['updateConnectionLog'] = () => {};
+const noopToggleConnectionLogSaved: ConnectionLogsActions['toggleConnectionLogSaved'] = () => {};
+const noopDeleteConnectionLog: ConnectionLogsActions['deleteConnectionLog'] = () => {};
+const noopClearUnsavedConnectionLogs: ConnectionLogsActions['clearUnsavedConnectionLogs'] = () => {};
+
+/** Subscribe to the connection log catalog plus its vault mutation actions. */
+export function useConnectionLogsStore(): {
+  connectionLogs: ConnectionLog[];
+  updateConnectionLog: ConnectionLogsActions['updateConnectionLog'];
+  toggleConnectionLogSaved: ConnectionLogsActions['toggleConnectionLogSaved'];
+  deleteConnectionLog: ConnectionLogsActions['deleteConnectionLog'];
+  clearUnsavedConnectionLogs: ConnectionLogsActions['clearUnsavedConnectionLogs'];
+} {
+  const snapshot = useSyncExternalStore(
+    subscribeConnectionLogs,
+    getConnectionLogsSnapshot,
+    getConnectionLogsSnapshot,
+  );
+  const actions = useSyncExternalStore(
+    subscribeConnectionLogsActions,
+    getConnectionLogsActions,
+    getConnectionLogsActions,
+  );
+  return {
+    connectionLogs: snapshot.connectionLogs as ConnectionLog[],
+    updateConnectionLog: actions?.updateConnectionLog ?? noopUpdateConnectionLog,
+    toggleConnectionLogSaved: actions?.toggleConnectionLogSaved ?? noopToggleConnectionLogSaved,
+    deleteConnectionLog: actions?.deleteConnectionLog ?? noopDeleteConnectionLog,
+    clearUnsavedConnectionLogs: actions?.clearUnsavedConnectionLogs ?? noopClearUnsavedConnectionLogs,
+  };
+}

application/state/notesStore.test.ts

@@ -0,0 +1,114 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import {
+  EMPTY_NOTES_SNAPSHOT,
+  getEmptyNotesSnapshot,
+  getNotesActions,
+  getNotesSnapshot,
+  publishNotesSnapshot,
+  registerNotesActions,
+  subscribeNotes,
+  subscribeNotesNoop,
+} from './notesStore.ts';
+
+test('notesStore notifies subscribers only when snapshot identity changes', () => {
+  const events: number[] = [];
+  const unsubscribe = subscribeNotes(() => {
+    events.push(getNotesSnapshot().notes.length);
+  });
+
+  const firstNotes = [{
+    id: 'n1',
+    title: 'One',
+    content: 'body',
+    tags: [],
+    createdAt: 1,
+    updatedAt: 1,
+    order: 1000,
+  }];
+  const firstGroups = ['Ops'];
+  publishNotesSnapshot({ notes: firstNotes, noteGroups: firstGroups });
+  assert.equal(events.at(-1), 1);
+  assert.equal(getNotesSnapshot().notes, firstNotes);
+  assert.equal(getNotesSnapshot().noteGroups, firstGroups);
+
+  publishNotesSnapshot({ notes: firstNotes, noteGroups: firstGroups });
+  assert.equal(events.length, 1);
+
+  const secondNotes = [
+    ...firstNotes,
+    {
+      id: 'n2',
+      title: 'Two',
+      content: 'more',
+      tags: [],
+      createdAt: 2,
+      updatedAt: 2,
+      order: 2000,
+    },
+  ];
+  publishNotesSnapshot({ notes: secondNotes, noteGroups: firstGroups });
+  assert.equal(events.at(-1), 2);
+
+  publishNotesSnapshot({ notes: secondNotes, noteGroups: ['Ops', 'DB'] });
+  assert.equal(events.length, 3);
+  assert.deepEqual(getNotesSnapshot().noteGroups, ['Ops', 'DB']);
+
+  unsubscribe();
+});
+
+test('notesStore gated helpers stay empty and never notify', () => {
+  let called = 0;
+  const unsub = subscribeNotesNoop(() => {
+    called += 1;
+  });
+  publishNotesSnapshot({
+    notes: [{
+      id: 'n1',
+      title: 'One',
+      content: 'body',
+      tags: [],
+      createdAt: 1,
+      updatedAt: 1,
+      order: 1000,
+    }],
+    noteGroups: ['Ops'],
+  });
+  assert.equal(called, 0);
+  assert.equal(getEmptyNotesSnapshot(), EMPTY_NOTES_SNAPSHOT);
+  assert.equal(getEmptyNotesSnapshot().notes.length, 0);
+  unsub();
+});
+
+test('useNotesStore source gates subscribe when enabled is false', async () => {
+  const { readFileSync } = await import('node:fs');
+  const source = readFileSync(new URL('./notesStore.ts', import.meta.url), 'utf8');
+  assert.match(source, /enabled \? subscribeNotes : subscribeNotesNoop/);
+  assert.match(source, /enabled \? subscribeNotesActions : subscribeNotesNoop/);
+  assert.match(source, /getNotesSnapshot/);
+  assert.doesNotMatch(
+    source,
+    /enabled \? getNotesSnapshot : getEmptyNotesSnapshot/,
+    'hidden notes mounts should keep the last live snapshot, not flash empty',
+  );
+});
+
+test('registerNotesActions exposes update handlers', () => {
+  const calls: string[] = [];
+  registerNotesActions({
+    updateNotes: () => {
+      calls.push('notes');
+    },
+    updateNoteGroups: () => {
+      calls.push('groups');
+    },
+  });
+  const actions = getNotesActions();
+  assert.ok(actions);
+  actions!.updateNotes([]);
+  actions!.updateNoteGroups([]);
+  assert.deepEqual(calls, ['notes', 'groups']);
+  registerNotesActions(null);
+  assert.equal(getNotesActions(), null);
+});

application/state/notesStore.ts

@@ -0,0 +1,143 @@
+import { useSyncExternalStore } from 'react';
+
+import type { VaultNote } from '../../domain/models';
+
+type Listener = () => void;
+
+export type NotesSnapshot = {
+  notes: readonly VaultNote[];
+  noteGroups: readonly string[];
+};
+
+export type NotesActions = {
+  updateNotes: (notes: VaultNote[]) => boolean | void;
+  updateNoteGroups: (groups: string[]) => void;
+};
+
+const EMPTY_NOTES: readonly VaultNote[] = Object.freeze([]);
+const EMPTY_NOTE_GROUPS: readonly string[] = Object.freeze([]);
+
+export const EMPTY_NOTES_SNAPSHOT: NotesSnapshot = Object.freeze({
+  notes: EMPTY_NOTES,
+  noteGroups: EMPTY_NOTE_GROUPS,
+});
+
+/**
+ * External store for vault notes so Notes / AI side-panel consumers can
+ * subscribe without forcing TerminalLayer re-renders on every note edit.
+ */
+class NotesStore {
+  private snapshot: NotesSnapshot = EMPTY_NOTES_SNAPSHOT;
+  private actions: NotesActions | null = null;
+  private listeners = new Set<Listener>();
+  private actionListeners = new Set<Listener>();
+
+  getSnapshot = (): NotesSnapshot => this.snapshot;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  setSnapshot(next: NotesSnapshot): void {
+    if (
+      this.snapshot.notes === next.notes
+      && this.snapshot.noteGroups === next.noteGroups
+    ) {
+      return;
+    }
+    this.snapshot = next;
+    for (const listener of this.listeners) {
+      listener();
+    }
+  }
+
+  getActions = (): NotesActions | null => this.actions;
+
+  subscribeActions = (listener: Listener): (() => void) => {
+    this.actionListeners.add(listener);
+    return () => {
+      this.actionListeners.delete(listener);
+    };
+  };
+
+  setActions(next: NotesActions | null): void {
+    if (this.actions === next) return;
+    this.actions = next;
+    for (const listener of this.actionListeners) {
+      listener();
+    }
+  }
+}
+
+export const notesStore = new NotesStore();
+
+export function publishNotesSnapshot(snapshot: NotesSnapshot): void {
+  notesStore.setSnapshot(snapshot);
+}
+
+export function getNotesSnapshot(): NotesSnapshot {
+  return notesStore.getSnapshot();
+}
+
+export function subscribeNotes(listener: Listener): () => void {
+  return notesStore.subscribe(listener);
+}
+
+/** No-op subscribe for gated (hidden) panel mounts. */
+export function subscribeNotesNoop(_listener: Listener): () => void {
+  return () => {};
+}
+
+export function getEmptyNotesSnapshot(): NotesSnapshot {
+  return EMPTY_NOTES_SNAPSHOT;
+}
+
+export function registerNotesActions(actions: NotesActions | null): void {
+  notesStore.setActions(actions);
+}
+
+export function getNotesActions(): NotesActions | null {
+  return notesStore.getActions();
+}
+
+export function subscribeNotesActions(listener: Listener): () => void {
+  return notesStore.subscribeActions(listener);
+}
+
+const noopUpdateNotes: NotesActions['updateNotes'] = () => {};
+const noopUpdateNoteGroups: NotesActions['updateNoteGroups'] = () => {};
+
+/**
+ * Subscribe to notes catalog + vault mutation actions for Notes / AI panels.
+ *
+ * Pass `{ enabled: false }` for retained-but-hidden mounts (e.g. terminal
+ * notes side panel) so vault note publishes do not re-render them. Snapshot
+ * reads still use the live store so reopen does not flash empty data.
+ */
+export function useNotesStore(options?: { enabled?: boolean }): {
+  notes: VaultNote[];
+  noteGroups: string[];
+  updateNotes: NotesActions['updateNotes'];
+  updateNoteGroups: NotesActions['updateNoteGroups'];
+} {
+  const enabled = options?.enabled !== false;
+  const snapshot = useSyncExternalStore(
+    enabled ? subscribeNotes : subscribeNotesNoop,
+    getNotesSnapshot,
+    getNotesSnapshot,
+  );
+  const actions = useSyncExternalStore(
+    enabled ? subscribeNotesActions : subscribeNotesNoop,
+    getNotesActions,
+    getNotesActions,
+  );
+  return {
+    notes: snapshot.notes as VaultNote[],
+    noteGroups: snapshot.noteGroups as string[],
+    updateNotes: actions?.updateNotes ?? noopUpdateNotes,
+    updateNoteGroups: actions?.updateNoteGroups ?? noopUpdateNoteGroups,
+  };
+}

application/state/sessionRestoreSettings.test.ts

@@ -88,7 +88,13 @@ test("session restore persistence can be disabled for non-main windows", () => {
   assert.match(hookSource, /if \(!persistSessionRestore\) return;/);
   assert.match(traySource, /useSessionState\(\{ persistSessionRestore: false \}\)/);
   assert.match(appSource, /window\.location\.hash\.startsWith\('#\/session-window'\)/);
-  assert.match(appSource, /persistSessionRestore: !isPeerSessionWindow/);
+  // App no longer calls useSessionState; SessionPublisher owns the hook and
+  // App passes the peer-window flag down to it.
+  assert.match(appSource, /<SessionPublisher persistSessionRestore=\{!isPeerSessionWindow\}>/);
+  assert.match(
+    readFileSync(new URL("../app/publishers/SessionPublisher.tsx", import.meta.url), "utf8"),
+    /useSessionState\(\{ persistSessionRestore \}\)/,
+  );
   assert.match(indexSource, /hash === '#\/session-window'/);
   assert.match(registerBridgesSource, /route: "session-window"/);
   assert.match(registerBridgesSource, /registerAsMainWindow: false/);
@@ -100,7 +106,8 @@ test("session restore persistence can be disabled for non-main windows", () => {
 });
 
 test("session peer windows do not run main-window startup effects", () => {
-  const appSource = readFileSync(new URL("../../App.tsx", import.meta.url), "utf8");
+  const appSource = readFileSync(new URL("../app/AppSideEffects.tsx", import.meta.url), "utf8");
+  const appRootSource = readFileSync(new URL("../../App.tsx", import.meta.url), "utf8");
   const autoSyncSource = readFileSync(new URL("./useAutoSync.ts", import.meta.url), "utf8");
   const startupEffectsSource = readFileSync(new URL("../app/useAppStartupEffects.ts", import.meta.url), "utf8");
   const updateCheckSource = readFileSync(new URL("./useUpdateCheck.ts", import.meta.url), "utf8");
@@ -112,7 +119,13 @@ test("session peer windows do not run main-window startup effects", () => {
   const trayPanelJumpIndex = appSource.indexOf("onTrayPanelJumpToSession");
 
   assert.match(appSource, /const isPeerSessionWindow = typeof window !== 'undefined' && window\.location\.hash\.startsWith\('#\/session-window'\)/);
-  assert.match(appSource, /useSettingsState\(\{[^}]*enableSettingsSync: !isPeerSessionWindow[^}]*enableSystemEffects: !isPeerSessionWindow/s);
+  // SettingsPublisher owns useSettingsState; App only forwards the peer-window
+  // flags to it.
+  assert.match(appRootSource, /<SettingsPublisher\s+enableSettingsSync=\{!isPeerSessionWindow\}\s+enableSystemEffects=\{!isPeerSessionWindow\}/s);
+  assert.match(
+    readFileSync(new URL("../app/publishers/SettingsPublisher.tsx", import.meta.url), "utf8"),
+    /useSettingsState\(\{ enableSettingsSync, enableSystemEffects \}\)/,
+  );
   assert.match(appSource, /useAppStartupEffects\(\{[^}]*enabled: !isPeerSessionWindow/s);
   assert.match(appSource, /useUpdateCheck\(\{[^}]*enabled: !isPeerSessionWindow/s);
   assert.match(appSource, /if \(isPeerSessionWindow \|\| !isVaultInitialized \|\| versionBackupAttemptedRef\.current\) return;/);

application/state/sessionSnapshotStore.test.ts

@@ -0,0 +1,118 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import type { TerminalSession } from '../../domain/models.ts';
+import {
+  EMPTY_SESSION_SNAPSHOT,
+  getSessionSnapshot,
+  getSessionSnapshotActions,
+  publishSessionSnapshot,
+  registerSessionSnapshotActions,
+  sessionSnapshotsEqual,
+  subscribeSessionSnapshot,
+} from './sessionSnapshotStore.ts';
+
+function makeSession(id: string): TerminalSession {
+  return { id, hostLabel: id, status: 'connected' } as TerminalSession;
+}
+
+test('sessionSnapshotStore notifies only when a field identity changes', () => {
+  const seen: number[] = [];
+  const unsubscribe = subscribeSessionSnapshot(() => {
+    seen.push(getSessionSnapshot().sessions.length);
+  });
+
+  const sessions = [makeSession('s1')];
+  const snapshot = { ...EMPTY_SESSION_SNAPSHOT, sessions, orphanSessions: sessions };
+  publishSessionSnapshot(snapshot);
+  assert.deepEqual(seen, [1]);
+  assert.equal(getSessionSnapshot().sessions, sessions);
+
+  publishSessionSnapshot({ ...snapshot });
+  assert.deepEqual(seen, [1]);
+
+  // Presentation-only fields still count: rename targets drive dialog state.
+  publishSessionSnapshot({ ...snapshot, sessionRenameTarget: sessions[0] });
+  assert.deepEqual(seen, [1, 1]);
+  assert.equal(getSessionSnapshot().sessionRenameTarget, sessions[0]);
+
+  unsubscribe();
+  publishSessionSnapshot(EMPTY_SESSION_SNAPSHOT);
+  assert.deepEqual(seen, [1, 1]);
+});
+
+test('sessionSnapshotsEqual compares every published field', () => {
+  assert.equal(
+    sessionSnapshotsEqual(EMPTY_SESSION_SNAPSHOT, { ...EMPTY_SESSION_SNAPSHOT }),
+    true,
+  );
+  assert.equal(
+    sessionSnapshotsEqual(EMPTY_SESSION_SNAPSHOT, {
+      ...EMPTY_SESSION_SNAPSHOT,
+      draggingSessionId: 's1',
+    }),
+    false,
+  );
+  assert.equal(
+    sessionSnapshotsEqual(EMPTY_SESSION_SNAPSHOT, { ...EMPTY_SESSION_SNAPSHOT, logViews: [] }),
+    false,
+  );
+});
+
+test('session actions register and unregister', () => {
+  assert.equal(getSessionSnapshotActions(), null);
+  const calls: string[] = [];
+  const noop = (() => {}) as never;
+  registerSessionSnapshotActions({
+    setActiveTabId: ((id: string) => calls.push(id)) as never,
+    closeSession: noop,
+    closeSessions: noop,
+    closeWorkspace: noop,
+    openLogView: noop,
+    closeLogView: noop,
+    setDraggingSessionId: noop,
+    startSessionRename: noop,
+    renameSessionInline: noop,
+    submitSessionRename: noop,
+    resetSessionRename: noop,
+    startWorkspaceRename: noop,
+    submitWorkspaceRename: noop,
+    resetWorkspaceRename: noop,
+    removeSessionFromWorkspace: noop,
+    setWorkspaceFocusedSession: noop,
+    toggleWorkspaceViewMode: noop,
+    createLocalTerminal: noop,
+    createSerialSession: noop,
+    connectToHost: noop,
+    updateSessionStatus: noop,
+    updateSessionFontSize: noop,
+    clearSessionFontSizeOverride: noop,
+    createWorkspaceWithHosts: noop,
+    createWorkspaceFromSessions: noop,
+    addSessionToWorkspace: noop,
+    appendHostToWorkspace: noop,
+    appendLocalTerminalToWorkspace: noop,
+    createWorkspaceFromTargets: noop,
+    updateSplitSizes: noop,
+    splitSession: noop,
+    reorderWorkspaceSessions: noop,
+    moveFocusInWorkspace: noop,
+    runSnippet: noop,
+    getOrderedWorkTabs: noop,
+    reorderTabs: noop,
+    toggleBroadcast: noop,
+    isBroadcastEnabled: noop,
+    copySession: noop,
+    copyWorkspace: noop,
+    createSessionFromCloneSource: noop,
+    updateSessionRestoreCwd: noop,
+    getSessionRestoreCwd: noop,
+    updateSessionDynamicTitle: noop,
+    updateSessionCodingCliProvider: noop,
+  });
+  getSessionSnapshotActions()?.setActiveTabId('vault');
+  assert.deepEqual(calls, ['vault']);
+
+  registerSessionSnapshotActions(null);
+  assert.equal(getSessionSnapshotActions(), null);
+});

application/state/sessionSnapshotStore.ts

@@ -0,0 +1,200 @@
+import { useSyncExternalStore } from 'react';
+
+import type { TerminalSession, Workspace } from '../../domain/models';
+import type { LogView } from './logViewState';
+import type { useSessionState } from './useSessionState';
+
+type SessionState = ReturnType<typeof useSessionState>;
+
+type Listener = () => void;
+
+/**
+ * Session/workspace catalog for shell surfaces. `activeTabId` is intentionally
+ * absent — it lives in `activeTabStore` so tab switches stay off this path.
+ */
+export type SessionSnapshot = {
+  sessions: readonly TerminalSession[];
+  /** Sessions with no workspace and not hidden from tabs; TopTabs renders these. */
+  orphanSessions: readonly TerminalSession[];
+  workspaces: readonly Workspace[];
+  logViews: readonly LogView[];
+  draggingSessionId: string | null;
+  sessionRenameTarget: TerminalSession | null;
+  workspaceRenameTarget: Workspace | null;
+};
+
+/**
+ * Session mutators the shell needs. Derived from the hook return so the store
+ * contract cannot drift from `useSessionState`.
+ */
+export type SessionSnapshotActions = Pick<
+  SessionState,
+  | 'setActiveTabId'
+  | 'closeSession'
+  | 'closeSessions'
+  | 'closeWorkspace'
+  | 'openLogView'
+  | 'closeLogView'
+  | 'setDraggingSessionId'
+  | 'startSessionRename'
+  | 'renameSessionInline'
+  | 'submitSessionRename'
+  | 'resetSessionRename'
+  | 'startWorkspaceRename'
+  | 'submitWorkspaceRename'
+  | 'resetWorkspaceRename'
+  | 'removeSessionFromWorkspace'
+  | 'setWorkspaceFocusedSession'
+  | 'toggleWorkspaceViewMode'
+  // Terminal / chrome mutators previously read only via App session runtime.
+  | 'createLocalTerminal'
+  | 'createSerialSession'
+  | 'connectToHost'
+  | 'updateSessionStatus'
+  | 'updateSessionFontSize'
+  | 'clearSessionFontSizeOverride'
+  | 'createWorkspaceWithHosts'
+  | 'createWorkspaceFromSessions'
+  | 'addSessionToWorkspace'
+  | 'appendHostToWorkspace'
+  | 'appendLocalTerminalToWorkspace'
+  | 'createWorkspaceFromTargets'
+  | 'updateSplitSizes'
+  | 'splitSession'
+  | 'reorderWorkspaceSessions'
+  | 'moveFocusInWorkspace'
+  | 'runSnippet'
+  | 'getOrderedWorkTabs'
+  | 'reorderTabs'
+  | 'toggleBroadcast'
+  | 'isBroadcastEnabled'
+  | 'copySession'
+  | 'copyWorkspace'
+  | 'createSessionFromCloneSource'
+  | 'updateSessionRestoreCwd'
+  | 'getSessionRestoreCwd'
+  | 'updateSessionDynamicTitle'
+  | 'updateSessionCodingCliProvider'
+>;
+
+const EMPTY_SESSIONS: readonly TerminalSession[] = Object.freeze([]);
+const EMPTY_WORKSPACES: readonly Workspace[] = Object.freeze([]);
+const EMPTY_LOG_VIEWS: readonly LogView[] = Object.freeze([]);
+
+export const EMPTY_SESSION_SNAPSHOT: SessionSnapshot = Object.freeze({
+  sessions: EMPTY_SESSIONS,
+  orphanSessions: EMPTY_SESSIONS,
+  workspaces: EMPTY_WORKSPACES,
+  logViews: EMPTY_LOG_VIEWS,
+  draggingSessionId: null,
+  sessionRenameTarget: null,
+  workspaceRenameTarget: null,
+});
+
+const SNAPSHOT_KEYS = Object.keys(EMPTY_SESSION_SNAPSHOT) as (keyof SessionSnapshot)[];
+
+export function sessionSnapshotsEqual(
+  prev: SessionSnapshot,
+  next: SessionSnapshot,
+): boolean {
+  return SNAPSHOT_KEYS.every((key) => prev[key] === next[key]);
+}
+
+/**
+ * External store for the session catalog so TopTabs, the terminal layer and
+ * the host tree can subscribe directly instead of receiving sessions through
+ * the App domain bags.
+ */
+class SessionSnapshotStore {
+  private snapshot: SessionSnapshot = EMPTY_SESSION_SNAPSHOT;
+  private actions: SessionSnapshotActions | null = null;
+  private listeners = new Set<Listener>();
+  private actionListeners = new Set<Listener>();
+
+  getSnapshot = (): SessionSnapshot => this.snapshot;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  setSnapshot(next: SessionSnapshot): void {
+    if (sessionSnapshotsEqual(this.snapshot, next)) return;
+    this.snapshot = next;
+    for (const listener of this.listeners) {
+      listener();
+    }
+  }
+
+  getActions = (): SessionSnapshotActions | null => this.actions;
+
+  subscribeActions = (listener: Listener): (() => void) => {
+    this.actionListeners.add(listener);
+    return () => {
+      this.actionListeners.delete(listener);
+    };
+  };
+
+  setActions(next: SessionSnapshotActions | null): void {
+    if (this.actions === next) return;
+    this.actions = next;
+    for (const listener of this.actionListeners) {
+      listener();
+    }
+  }
+}
+
+export const sessionSnapshotStore = new SessionSnapshotStore();
+
+export function publishSessionSnapshot(snapshot: SessionSnapshot): void {
+  sessionSnapshotStore.setSnapshot(snapshot);
+}
+
+export function getSessionSnapshot(): SessionSnapshot {
+  return sessionSnapshotStore.getSnapshot();
+}
+
+export function subscribeSessionSnapshot(listener: Listener): () => void {
+  return sessionSnapshotStore.subscribe(listener);
+}
+
+export function registerSessionSnapshotActions(
+  actions: SessionSnapshotActions | null,
+): void {
+  sessionSnapshotStore.setActions(actions);
+}
+
+export function getSessionSnapshotActions(): SessionSnapshotActions | null {
+  return sessionSnapshotStore.getActions();
+}
+
+export function subscribeSessionSnapshotActions(listener: Listener): () => void {
+  return sessionSnapshotStore.subscribeActions(listener);
+}
+
+/** Subscribe to the whole session catalog. Prefer a narrower selector hook. */
+export function useSessionSnapshot(): SessionSnapshot {
+  return useSyncExternalStore(
+    subscribeSessionSnapshot,
+    getSessionSnapshot,
+    getSessionSnapshot,
+  );
+}
+
+/** Subscribe to one session field so unrelated session churn stays out. */
+export function useSessionSnapshotField<K extends keyof SessionSnapshot>(
+  field: K,
+): SessionSnapshot[K] {
+  const read = () => getSessionSnapshot()[field];
+  return useSyncExternalStore(subscribeSessionSnapshot, read, read);
+}
+
+export function useSessionSnapshotActions(): SessionSnapshotActions | null {
+  return useSyncExternalStore(
+    subscribeSessionSnapshotActions,
+    getSessionSnapshotActions,
+    getSessionSnapshotActions,
+  );
+}

application/state/sessionWorkspaceDetach.test.ts

@@ -147,6 +147,7 @@ test("closing one split pane keeps the other terminal as an orphan tab", () => {
       workspaceId: "ws-1",
       layoutResult,
       remainingSessions: nextSessions,
+      preferredTabId: "s-outside",
     }),
     "s2",
   );
@@ -197,6 +198,81 @@ test("closing the last visible solo tab does not fall back to a hidden MCP sessi
   );
 });
 
+test("closing a temporary solo tab restores the previously focused tab", () => {
+  const standalone = (id: string, status: TerminalSession["status"] = "connected"): TerminalSession => ({
+    ...session(id),
+    workspaceId: undefined,
+    status,
+  });
+  const remainingSessions = [
+    standalone("s1", "disconnected"),
+    standalone("s2"),
+    standalone("s3"),
+    standalone("s4"),
+    standalone("s5", "disconnected"),
+    standalone("s6"),
+  ];
+  const layoutResult = closeSessionWorkspaceLayoutState([], undefined, "s7");
+
+  assert.equal(
+    resolveActiveTabAfterCloseSession({
+      currentActiveTabId: "s7",
+      closedSessionId: "s7",
+      workspaceId: undefined,
+      layoutResult,
+      remainingSessions,
+      preferredTabId: "s5",
+    }),
+    "s5",
+  );
+});
+
+test("closing a temporary solo tab ignores a preferred tab that no longer exists", () => {
+  const standalone = (id: string): TerminalSession => ({
+    ...session(id),
+    workspaceId: undefined,
+  });
+  const remainingSessions = [standalone("s1"), standalone("s2"), standalone("s6")];
+  const layoutResult = closeSessionWorkspaceLayoutState([], undefined, "s7");
+
+  assert.equal(
+    resolveActiveTabAfterCloseSession({
+      currentActiveTabId: "s7",
+      closedSessionId: "s7",
+      workspaceId: undefined,
+      layoutResult,
+      remainingSessions,
+      preferredTabId: "s5",
+    }),
+    "s6",
+  );
+});
+
+test("closeSessionsState restores the previous tab instead of the newest remaining tab", () => {
+  const standaloneSession = (id: string): TerminalSession => ({
+    ...session(id),
+    workspaceId: undefined,
+  });
+
+  const result = closeSessionsState({
+    sessions: [
+      standaloneSession("s1"),
+      standaloneSession("s2"),
+      standaloneSession("s5"),
+      standaloneSession("s6"),
+      standaloneSession("s7"),
+    ],
+    workspaces: [],
+    sessionIds: ["s7"],
+    currentActiveTabId: "s7",
+    preferredTabId: "s5",
+    tabOrder: ["s1", "s2", "s5", "s6", "s7"],
+  });
+
+  assert.equal(result.activeTabId, "s5");
+  assert.deepEqual(result.sessions.map((candidate) => candidate.id), ["s1", "s2", "s5", "s6"]);
+});
+
 test("closing several standalone sessions removes the whole batch", () => {
   const standaloneSession = (id: string): TerminalSession => ({
     ...session(id),

application/state/sessionWorkspaceDetach.ts

@@ -129,22 +129,64 @@ export function applyCloseSessionToSessions(
   ));
 }
 
+export function isPreferredTabAvailableAfterClose(
+  input: {
+    preferredTabId: string | null | undefined;
+    closedSessionId: string;
+    layoutResult: CloseSessionWorkspaceLayoutResult;
+    remainingSessions: readonly TerminalSession[];
+  },
+): input is {
+  preferredTabId: string;
+  closedSessionId: string;
+  layoutResult: CloseSessionWorkspaceLayoutResult;
+  remainingSessions: readonly TerminalSession[];
+} {
+  const { preferredTabId, closedSessionId, layoutResult, remainingSessions } = input;
+  if (!preferredTabId || preferredTabId === closedSessionId) return false;
+  if (
+    preferredTabId === layoutResult.dissolvedWorkspaceId
+    || preferredTabId === layoutResult.removedWorkspaceId
+  ) {
+    return false;
+  }
+  if (preferredTabId === "vault" || preferredTabId === "sftp") return true;
+  if (layoutResult.workspaces.some((workspace) => workspace.id === preferredTabId)) return true;
+  return remainingSessions.some((session) => (
+    session.id === preferredTabId
+    && !session.workspaceId
+    && !session.hiddenFromTabs
+  ));
+}
+
 export function resolveActiveTabAfterCloseSession({
   currentActiveTabId,
   closedSessionId,
   workspaceId,
   layoutResult,
   remainingSessions,
+  preferredTabId,
 }: {
   currentActiveTabId: string | null;
   closedSessionId: string;
   workspaceId: string | undefined;
   layoutResult: CloseSessionWorkspaceLayoutResult;
   remainingSessions: readonly TerminalSession[];
+  preferredTabId?: string | null;
 }): string | null {
   const fallbackWorkspace = layoutResult.workspaces[layoutResult.workspaces.length - 1];
   const fallbackSolo = remainingSessions.filter((session) => !session.workspaceId && !session.hiddenFromTabs).slice(-1)[0];
+  const preferredInput = {
+    preferredTabId,
+    closedSessionId,
+    layoutResult,
+    remainingSessions,
+  };
+  const preferredFallback = isPreferredTabAvailableAfterClose(preferredInput)
+    ? preferredInput.preferredTabId
+    : undefined;
   const fallback = layoutResult.lastRemainingSessionId
+    ?? preferredFallback
     ?? fallbackWorkspace?.id
     ?? fallbackSolo?.id
     ?? "vault";
@@ -166,12 +208,14 @@ export function closeSessionsState({
   workspaces,
   sessionIds,
   currentActiveTabId,
+  preferredTabId,
   tabOrder,
 }: {
   sessions: readonly TerminalSession[];
   workspaces: readonly Workspace[];
   sessionIds: readonly string[];
   currentActiveTabId: string | null;
+  preferredTabId?: string | null;
   tabOrder: readonly string[];
 }): CloseSessionsStateResult {
   let nextSessions = [...sessions];
@@ -207,6 +251,7 @@ export function closeSessionsState({
       workspaceId,
       layoutResult,
       remainingSessions: nextSessions,
+      preferredTabId,
     });
     if (activeTabAfterClose) {
       nextActiveTabId = activeTabAfterClose;

application/state/settingsChromeStore.test.ts

@@ -0,0 +1,170 @@
+import assert from 'node:assert/strict';
+import { readFileSync } from 'node:fs';
+import test from 'node:test';
+
+import {
+  DEFAULT_SETTINGS_CHROME_SNAPSHOT,
+  getSettingsChromeActions,
+  getSettingsChromeSnapshot,
+  publishSettingsChromeSnapshot,
+  registerSettingsChromeActions,
+  settingsChromeSnapshotsEqual,
+  subscribeSettingsChrome,
+  subscribeSettingsChromeActions,
+  type SettingsChromeSnapshot,
+} from './settingsChromeStore.ts';
+
+type SnapshotKey = keyof SettingsChromeSnapshot;
+
+/**
+ * Derive the probe value instead of hard-coding a field list: the chrome slice
+ * grows as surfaces move off the App settings bag, and this suite is about the
+ * dedupe contract, not about which fields happen to be in it today.
+ */
+function mutate(value: unknown): unknown {
+  if (typeof value === 'boolean') return !value;
+  if (typeof value === 'number') return value + 1;
+  if (typeof value === 'string') return `${value}-changed`;
+  throw new Error(`Unsupported snapshot field type: ${typeof value}`);
+}
+
+test('settingsChromeStore ignores structurally identical republishes', () => {
+  const base = getSettingsChromeSnapshot();
+  let events = 0;
+  const unsubscribe = subscribeSettingsChrome(() => {
+    events += 1;
+  });
+
+  // useSettingsState rebuilds this object literal on every render, so a fresh
+  // identity with unchanged fields must not wake chrome consumers.
+  publishSettingsChromeSnapshot({ ...base });
+  publishSettingsChromeSnapshot({ ...base });
+  assert.equal(events, 0);
+  assert.equal(getSettingsChromeSnapshot(), base);
+
+  unsubscribe();
+});
+
+test('settingsChromeStore notifies on any single chrome field change', () => {
+  const base = getSettingsChromeSnapshot();
+  const keys = Object.keys(base) as SnapshotKey[];
+  assert.ok(keys.length > 0, 'chrome snapshot must publish at least one field');
+
+  for (const key of keys) {
+    let events = 0;
+    const unsubscribe = subscribeSettingsChrome(() => {
+      events += 1;
+    });
+
+    const changed = { ...base, [key]: mutate(base[key]) } as SettingsChromeSnapshot;
+    publishSettingsChromeSnapshot(changed);
+    assert.equal(events, 1, `expected a notification for ${key}`);
+    assert.equal(getSettingsChromeSnapshot()[key], changed[key]);
+
+    publishSettingsChromeSnapshot({ ...changed });
+    assert.equal(events, 1, `expected no repeat notification for ${key}`);
+
+    publishSettingsChromeSnapshot(base);
+    assert.equal(events, 2, `expected a restore notification for ${key}`);
+
+    unsubscribe();
+  }
+
+  assert.equal(getSettingsChromeSnapshot(), base);
+});
+
+test('settingsChromeStore stops notifying after unsubscribe', () => {
+  const base = getSettingsChromeSnapshot();
+  const [firstKey] = Object.keys(base) as SnapshotKey[];
+  let events = 0;
+  const unsubscribe = subscribeSettingsChrome(() => {
+    events += 1;
+  });
+
+  unsubscribe();
+  publishSettingsChromeSnapshot({
+    ...base,
+    [firstKey]: mutate(base[firstKey]),
+  } as SettingsChromeSnapshot);
+  assert.equal(events, 0);
+
+  publishSettingsChromeSnapshot(base);
+});
+
+test('chrome snapshot fields stay in sync with what useSettingsState publishes', () => {
+  // The whole point of the slice is that chrome leaves can stop reading the
+  // App settings bag. A field the publisher forgets would silently freeze at
+  // its default, so pin the two shapes together.
+  const source = readFileSync(new URL('./useSettingsState.ts', import.meta.url), 'utf8');
+  const callStart = source.indexOf('publishSettingsChromeSnapshot({');
+  assert.notEqual(callStart, -1, 'useSettingsState must publish the chrome slice');
+  const callEnd = source.indexOf('});', callStart);
+  assert.notEqual(callEnd, -1);
+
+  const published = source
+    .slice(callStart, callEnd)
+    .split('\n')
+    .slice(1)
+    .map((line) => line.trim().match(/^([A-Za-z0-9_]+)\s*[:,]/)?.[1])
+    .filter((name): name is string => Boolean(name));
+
+  assert.deepEqual(
+    published.slice().sort(),
+    Object.keys(DEFAULT_SETTINGS_CHROME_SNAPSHOT).sort(),
+  );
+});
+
+test('settingsChromeSnapshotsEqual compares by field, not object identity', () => {
+  const base = DEFAULT_SETTINGS_CHROME_SNAPSHOT;
+  assert.equal(settingsChromeSnapshotsEqual({ ...base }, { ...base }), true);
+  assert.equal(
+    settingsChromeSnapshotsEqual(base, { ...base, windowOpacity: 0.8 }),
+    false,
+  );
+  assert.equal(
+    settingsChromeSnapshotsEqual(base, { ...base, showSftpTab: !base.showSftpTab }),
+    false,
+  );
+});
+
+test('registerSettingsChromeActions exposes the theme and opacity setters', () => {
+  const calls: string[] = [];
+  let actionEvents = 0;
+  const unsubscribe = subscribeSettingsChromeActions(() => {
+    actionEvents += 1;
+  });
+
+  registerSettingsChromeActions({
+    setTheme: () => calls.push('theme'),
+    setWindowOpacity: () => calls.push('opacity'),
+  });
+
+  const actions = getSettingsChromeActions();
+  assert.ok(actions);
+  actions.setTheme('light');
+  actions.setWindowOpacity(0.5);
+  assert.deepEqual(calls, ['theme', 'opacity']);
+  assert.equal(actionEvents, 1);
+
+  registerSettingsChromeActions(null);
+  assert.equal(getSettingsChromeActions(), null);
+  assert.equal(actionEvents, 2);
+
+  unsubscribe();
+});
+
+test('setter churn never invalidates the chrome value snapshot', () => {
+  // useSettingsState re-registers on every setter identity change; chrome
+  // consumers of the value snapshot must not re-render for that.
+  let valueEvents = 0;
+  const unsubscribe = subscribeSettingsChrome(() => {
+    valueEvents += 1;
+  });
+
+  registerSettingsChromeActions({ setTheme: () => {}, setWindowOpacity: () => {} });
+  registerSettingsChromeActions({ setTheme: () => {}, setWindowOpacity: () => {} });
+  assert.equal(valueEvents, 0);
+
+  registerSettingsChromeActions(null);
+  unsubscribe();
+});

application/state/settingsChromeStore.ts

@@ -0,0 +1,181 @@
+import { useSyncExternalStore } from 'react';
+
+import type { UILanguage } from '../../domain/models/connection';
+import type { DynamicTabTitleMode } from '../../domain/models/terminal';
+import type { HostClickBehavior } from '../../domain/hostClickBehavior';
+import type { TerminalSidePanelAutoOpenTab } from '../../domain/terminalSidePanelAutoOpen';
+
+type Listener = () => void;
+
+export type SettingsChromeTheme = 'dark' | 'light' | 'system';
+
+/**
+ * Chrome-facing settings slice. Keep this aligned with what AppView / TopTabs /
+ * HostTree actually read. Unrelated settings edits must not rebuild App chrome
+ * domain bags — leaves subscribe here instead of receiving the whole settings
+ * object through domain props.
+ */
+export type SettingsChromeSnapshot = {
+  theme: SettingsChromeTheme;
+  resolvedTheme: 'light' | 'dark';
+  lightUiThemeId: string;
+  darkUiThemeId: string;
+  uiLanguage: UILanguage;
+  windowOpacity: number;
+  showSftpTab: boolean;
+  showHostTreeSidebar: boolean;
+  showRecentHosts: boolean;
+  hostClickBehavior: HostClickBehavior;
+  showOnlyUngroupedHostsInRoot: boolean;
+  dynamicTabTitleMode: DynamicTabTitleMode;
+  disableTerminalFontZoom: boolean;
+  restoreTerminalCwd: boolean;
+  terminalSidePanelAutoOpen: boolean;
+  terminalSidePanelAutoOpenTab: TerminalSidePanelAutoOpenTab;
+};
+
+/**
+ * Setters chrome leaves need. Kept on a separate slot from the value snapshot:
+ * `useSettingsState` rebuilds these callbacks on its own cadence, and that must
+ * never invalidate the value snapshot.
+ */
+export type SettingsChromeActions = {
+  setTheme: (theme: SettingsChromeTheme) => void;
+  setWindowOpacity: (opacity: number) => void;
+};
+
+export const DEFAULT_SETTINGS_CHROME_SNAPSHOT: SettingsChromeSnapshot = Object.freeze({
+  theme: 'system',
+  resolvedTheme: 'dark',
+  lightUiThemeId: 'default',
+  darkUiThemeId: 'default',
+  uiLanguage: 'en',
+  windowOpacity: 1,
+  showSftpTab: true,
+  showHostTreeSidebar: true,
+  showRecentHosts: true,
+  hostClickBehavior: 'connect',
+  showOnlyUngroupedHostsInRoot: false,
+  dynamicTabTitleMode: 'off',
+  disableTerminalFontZoom: false,
+  restoreTerminalCwd: true,
+  terminalSidePanelAutoOpen: false,
+  terminalSidePanelAutoOpenTab: 'ai',
+} satisfies SettingsChromeSnapshot);
+
+export function settingsChromeSnapshotsEqual(
+  a: SettingsChromeSnapshot,
+  b: SettingsChromeSnapshot,
+): boolean {
+  return a.theme === b.theme
+    && a.resolvedTheme === b.resolvedTheme
+    && a.lightUiThemeId === b.lightUiThemeId
+    && a.darkUiThemeId === b.darkUiThemeId
+    && a.uiLanguage === b.uiLanguage
+    && a.windowOpacity === b.windowOpacity
+    && a.showSftpTab === b.showSftpTab
+    && a.showHostTreeSidebar === b.showHostTreeSidebar
+    && a.showRecentHosts === b.showRecentHosts
+    && a.hostClickBehavior === b.hostClickBehavior
+    && a.showOnlyUngroupedHostsInRoot === b.showOnlyUngroupedHostsInRoot
+    && a.dynamicTabTitleMode === b.dynamicTabTitleMode
+    && a.disableTerminalFontZoom === b.disableTerminalFontZoom
+    && a.restoreTerminalCwd === b.restoreTerminalCwd
+    && a.terminalSidePanelAutoOpen === b.terminalSidePanelAutoOpen
+    && a.terminalSidePanelAutoOpenTab === b.terminalSidePanelAutoOpenTab;
+}
+
+class SettingsChromeStore {
+  private snapshot: SettingsChromeSnapshot = DEFAULT_SETTINGS_CHROME_SNAPSHOT;
+  private actions: SettingsChromeActions | null = null;
+  private listeners = new Set<Listener>();
+  private actionListeners = new Set<Listener>();
+
+  getSnapshot = (): SettingsChromeSnapshot => this.snapshot;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  setSnapshot(next: SettingsChromeSnapshot): void {
+    if (settingsChromeSnapshotsEqual(this.snapshot, next)) return;
+    this.snapshot = next;
+    for (const listener of this.listeners) {
+      listener();
+    }
+  }
+
+  getActions = (): SettingsChromeActions | null => this.actions;
+
+  subscribeActions = (listener: Listener): (() => void) => {
+    this.actionListeners.add(listener);
+    return () => {
+      this.actionListeners.delete(listener);
+    };
+  };
+
+  setActions(next: SettingsChromeActions | null): void {
+    if (this.actions === next) return;
+    this.actions = next;
+    for (const listener of this.actionListeners) {
+      listener();
+    }
+  }
+}
+
+export const settingsChromeStore = new SettingsChromeStore();
+
+export function publishSettingsChromeSnapshot(
+  snapshot: SettingsChromeSnapshot,
+): void {
+  settingsChromeStore.setSnapshot(snapshot);
+}
+
+export function getSettingsChromeSnapshot(): SettingsChromeSnapshot {
+  return settingsChromeStore.getSnapshot();
+}
+
+export function subscribeSettingsChrome(listener: Listener): () => void {
+  return settingsChromeStore.subscribe(listener);
+}
+
+export function registerSettingsChromeActions(
+  actions: SettingsChromeActions | null,
+): void {
+  settingsChromeStore.setActions(actions);
+}
+
+export function getSettingsChromeActions(): SettingsChromeActions | null {
+  return settingsChromeStore.getActions();
+}
+
+export function subscribeSettingsChromeActions(listener: Listener): () => void {
+  return settingsChromeStore.subscribeActions(listener);
+}
+
+export function useSettingsChromeStore(): SettingsChromeSnapshot {
+  return useSyncExternalStore(
+    subscribeSettingsChrome,
+    getSettingsChromeSnapshot,
+    getSettingsChromeSnapshot,
+  );
+}
+
+const noopSetTheme: SettingsChromeActions['setTheme'] = () => {};
+const noopSetWindowOpacity: SettingsChromeActions['setWindowOpacity'] = () => {};
+
+/** Chrome setters, safe to call before `useSettingsState` has registered. */
+export function useSettingsChromeActions(): SettingsChromeActions {
+  const actions = useSyncExternalStore(
+    subscribeSettingsChromeActions,
+    getSettingsChromeActions,
+    getSettingsChromeActions,
+  );
+  return {
+    setTheme: actions?.setTheme ?? noopSetTheme,
+    setWindowOpacity: actions?.setWindowOpacity ?? noopSetWindowOpacity,
+  };
+}

application/state/settingsStorageSync.ts

@@ -28,6 +28,7 @@ import {
   STORAGE_KEY_SFTP_TRANSFER_CONCURRENCY,
   STORAGE_KEY_SSH_TRANSPORT_IDLE_TTL_MS,
   STORAGE_KEY_SFTP_USE_COMPRESSED_UPLOAD,
+  STORAGE_KEY_SFTP_SKIP_UNCHANGED,
   STORAGE_KEY_SHOW_ONLY_UNGROUPED_HOSTS_IN_ROOT,
   STORAGE_KEY_SHOW_RECENT_HOSTS,
   STORAGE_KEY_HOST_CLICK_BEHAVIOR,
@@ -79,6 +80,7 @@ interface UseSettingsStorageSyncParams {
   sftpAutoSync: boolean;
   sftpShowHiddenFiles: boolean;
   sftpUseCompressedUpload: boolean;
+  sftpSkipUnchanged: boolean;
   sftpAutoOpenSidebar: boolean;
   sftpFollowTerminalCwd: boolean;
   sftpDefaultViewMode: 'list' | 'tree';
@@ -125,6 +127,7 @@ interface UseSettingsStorageSyncParams {
   setSftpAutoSync: Dispatch<SetStateAction<boolean>>;
   setSftpShowHiddenFiles: Dispatch<SetStateAction<boolean>>;
   setSftpUseCompressedUpload: Dispatch<SetStateAction<boolean>>;
+  setSftpSkipUnchanged: Dispatch<SetStateAction<boolean>>;
   setSftpAutoOpenSidebar: Dispatch<SetStateAction<boolean>>;
   setSftpFollowTerminalCwd: Dispatch<SetStateAction<boolean>>;
   setSftpDefaultViewMode: Dispatch<SetStateAction<'list' | 'tree'>>;
@@ -165,7 +168,7 @@ export function useSettingsStorageSync({
   customCSS, uiFontFamilyId, hotkeyScheme, uiLanguage,
   terminalThemeId, followAppTerminalTheme, terminalFontFamilyId, terminalFontSize,
   sftpDoubleClickBehavior, sftpAutoSync, sftpShowHiddenFiles,
-  sftpUseCompressedUpload, sftpAutoOpenSidebar, sftpFollowTerminalCwd, sftpDefaultViewMode,
+  sftpUseCompressedUpload, sftpSkipUnchanged, sftpAutoOpenSidebar, sftpFollowTerminalCwd, sftpDefaultViewMode,
   showRecentHosts, hostClickBehavior, showOnlyUngroupedHostsInRoot, showSftpTab, showHostTreeSidebar, terminalSidePanelAutoOpen, terminalSidePanelAutoOpenTab, shellOnlyTabNumberShortcuts, disableTerminalFontZoom, restorePreviousSession, restoreTerminalCwd,
   editorWordWrap, sessionLogsEnabled, sessionLogsDir, sessionLogsFormat, sessionLogsTimestampsEnabled, sshDebugLogsEnabled, sshDeepLinkEnabled, jmsDeepLinkEnabled, explorerContextMenuEnabled,
   globalHotkeyEnabled, autoUpdateEnabled, windowOpacity, appIconVariant,
@@ -174,7 +177,7 @@ export function useSettingsStorageSync({
   setTerminalThemeId, setTerminalThemeDarkId, setTerminalThemeLightId,
   setFollowAppTerminalThemeState, setTerminalFontFamilyId, setTerminalFontSize,
   setSftpDoubleClickBehavior, setSftpAutoSync, setSftpShowHiddenFiles,
-  setSftpUseCompressedUpload, setSftpAutoOpenSidebar, setSftpFollowTerminalCwd, setSftpDefaultViewMode,
+  setSftpUseCompressedUpload, setSftpSkipUnchanged, setSftpAutoOpenSidebar, setSftpFollowTerminalCwd, setSftpDefaultViewMode,
   setShowRecentHostsState, setHostClickBehaviorState, setShowOnlyUngroupedHostsInRootState, setShowSftpTabState, setShowHostTreeSidebarState, setTerminalSidePanelAutoOpenState, setTerminalSidePanelAutoOpenTabState, setShellOnlyTabNumberShortcutsState, setDisableTerminalFontZoomState, setRestorePreviousSessionState, setRestoreTerminalCwdState,
   setEditorWordWrapState, setSessionLogsEnabled, setSessionLogsDir, setSessionLogsFormat, setSessionLogsTimestampsEnabled, setSshDebugLogsEnabled, setSshDeepLinkEnabledState, setJmsDeepLinkEnabledState, setExplorerContextMenuEnabledState,
   setGlobalHotkeyEnabled, setWindowOpacity, setAppIconVariant, setAutoUpdateEnabled, setWorkspaceFocusStyleState,
@@ -189,7 +192,7 @@ export function useSettingsStorageSync({
     customCSS, uiFontFamilyId, hotkeyScheme, uiLanguage,
     terminalThemeId, followAppTerminalTheme, terminalFontFamilyId, terminalFontSize,
     sftpDoubleClickBehavior, sftpAutoSync, sftpShowHiddenFiles,
-    sftpUseCompressedUpload, sftpAutoOpenSidebar, sftpFollowTerminalCwd, sftpDefaultViewMode,
+    sftpUseCompressedUpload, sftpSkipUnchanged, sftpAutoOpenSidebar, sftpFollowTerminalCwd, sftpDefaultViewMode,
     showRecentHosts, hostClickBehavior, showOnlyUngroupedHostsInRoot, showSftpTab, showHostTreeSidebar, terminalSidePanelAutoOpen, terminalSidePanelAutoOpenTab, shellOnlyTabNumberShortcuts, disableTerminalFontZoom, restorePreviousSession, restoreTerminalCwd,
     editorWordWrap, sessionLogsEnabled, sessionLogsDir, sessionLogsFormat, sessionLogsTimestampsEnabled, sshDebugLogsEnabled, sshDeepLinkEnabled, jmsDeepLinkEnabled, explorerContextMenuEnabled,
     globalHotkeyEnabled, autoUpdateEnabled, windowOpacity, appIconVariant,
@@ -199,7 +202,7 @@ export function useSettingsStorageSync({
     customCSS, uiFontFamilyId, hotkeyScheme, uiLanguage,
     terminalThemeId, followAppTerminalTheme, terminalFontFamilyId, terminalFontSize,
     sftpDoubleClickBehavior, sftpAutoSync, sftpShowHiddenFiles,
-    sftpUseCompressedUpload, sftpAutoOpenSidebar, sftpFollowTerminalCwd, sftpDefaultViewMode,
+    sftpUseCompressedUpload, sftpSkipUnchanged, sftpAutoOpenSidebar, sftpFollowTerminalCwd, sftpDefaultViewMode,
     showRecentHosts, hostClickBehavior, showOnlyUngroupedHostsInRoot, showSftpTab, showHostTreeSidebar, terminalSidePanelAutoOpen, terminalSidePanelAutoOpenTab, shellOnlyTabNumberShortcuts, disableTerminalFontZoom, restorePreviousSession, restoreTerminalCwd,
     editorWordWrap, sessionLogsEnabled, sessionLogsDir, sessionLogsFormat, sessionLogsTimestampsEnabled, sshDebugLogsEnabled, sshDeepLinkEnabled, jmsDeepLinkEnabled, explorerContextMenuEnabled,
     globalHotkeyEnabled, autoUpdateEnabled, windowOpacity, appIconVariant,
@@ -379,6 +382,12 @@ export function useSettingsStorageSync({
           setSftpUseCompressedUpload(newValue);
         }
       }
+      if (e.key === STORAGE_KEY_SFTP_SKIP_UNCHANGED && e.newValue !== null) {
+        const newValue = e.newValue === 'true';
+        if (newValue !== s.sftpSkipUnchanged) {
+          setSftpSkipUnchanged(newValue);
+        }
+      }
       // Sync SFTP auto-open sidebar setting from other windows
       if (e.key === STORAGE_KEY_SFTP_AUTO_OPEN_SIDEBAR && e.newValue !== null) {
         const newValue = e.newValue === 'true';
@@ -542,6 +551,7 @@ export function useSettingsStorageSync({
     setSftpTransferConcurrencyState,
     setSshTransportIdleTtlMsState,
     setSftpUseCompressedUpload,
+    setSftpSkipUnchanged,
     setShowOnlyUngroupedHostsInRootState,
     setShowHostTreeSidebarState,
     setTerminalSidePanelAutoOpenState,

application/state/sftp/columnLayout.ts

@@ -0,0 +1,32 @@
+export type SortField = "name" | "size" | "modified" | "type";
+export type SortOrder = "asc" | "desc";
+
+export interface ColumnWidths {
+  name: number;
+  modified: number;
+  size: number;
+  type: number;
+}
+
+export type SftpColumnVisibility = Record<keyof ColumnWidths, boolean>;
+
+export const DEFAULT_SFTP_COLUMN_VISIBILITY: SftpColumnVisibility = {
+  name: true,
+  modified: true,
+  size: true,
+  type: true,
+};
+
+export const normalizeSftpColumnVisibility = (value: unknown): SftpColumnVisibility => {
+  if (!value || typeof value !== "object" || Array.isArray(value)) {
+    return DEFAULT_SFTP_COLUMN_VISIBILITY;
+  }
+
+  const stored = value as Partial<Record<keyof ColumnWidths, unknown>>;
+  return {
+    name: true,
+    modified: stored.modified !== false,
+    size: stored.size !== false,
+    type: stored.type !== false,
+  };
+};

application/state/sftp/externalDragDropRetry.test.ts

@@ -0,0 +1,186 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import type { TransferTask } from "../../../domain/models";
+import {
+  isExternalDragDropFileUpload,
+  retryExternalDragDropFileUpload,
+} from "./externalDragDropRetry";
+
+const baseTask = (overrides: Partial<TransferTask> = {}): TransferTask => ({
+  id: "child-1",
+  fileName: "a.txt",
+  sourcePath: "/tmp/docs/a.txt",
+  targetPath: "/remote/docs/a.txt",
+  sourceConnectionId: "external",
+  targetConnectionId: "conn-1",
+  targetHostId: "host-1",
+  direction: "upload",
+  status: "failed",
+  totalBytes: 12,
+  transferredBytes: 0,
+  speed: 0,
+  startTime: 1,
+  isDirectory: false,
+  origin: "drag-drop",
+  parentTaskId: "folder-1",
+  error: "Network error",
+  ...overrides,
+});
+
+test("detects progressive drag-drop file children as retryable", () => {
+  assert.equal(isExternalDragDropFileUpload(baseTask()), true);
+  assert.equal(isExternalDragDropFileUpload(baseTask({ isDirectory: true })), false);
+  assert.equal(isExternalDragDropFileUpload(baseTask({ origin: "manual" })), false);
+  assert.equal(isExternalDragDropFileUpload(baseTask({ sourceConnectionId: "local" })), false);
+  assert.equal(isExternalDragDropFileUpload(baseTask({ status: "completed" })), false);
+  assert.equal(isExternalDragDropFileUpload(baseTask({ retryable: false })), false);
+});
+
+test("retry reuses the same transfer id and starts a stream upload", async () => {
+  const patches: Array<{ id: string; updates: Partial<TransferTask> }> = [];
+  const streams: Array<Record<string, unknown>> = [];
+
+  // No pool acquire → falls back to browse sftp id.
+  const result = await retryExternalDragDropFileUpload(baseTask(), {
+    getBrowseSftpId: () => "sftp-live",
+    startStreamTransfer: async (options) => {
+      streams.push(options as unknown as Record<string, unknown>);
+      return { transferId: options.transferId };
+    },
+    onPatch: (taskId, updates) => patches.push({ id: taskId, updates }),
+  });
+
+  assert.equal(result.success, true);
+  assert.equal(streams.length, 1);
+  assert.equal(streams[0].transferId, "child-1");
+  assert.equal(streams[0].sourcePath, "/tmp/docs/a.txt");
+  assert.equal(streams[0].targetPath, "/remote/docs/a.txt");
+  assert.equal(streams[0].targetSftpId, "sftp-live");
+  assert.equal(patches[0].updates.status, "transferring");
+  assert.equal(patches.at(-1)?.updates.status, "completed");
+});
+
+test("retry prefers a dedicated pool session over the browse sftp id", async () => {
+  let released = false;
+  let acquired = false;
+  const result = await retryExternalDragDropFileUpload(baseTask(), {
+    getBrowseSftpId: () => "sftp-live",
+    acquireTransferSession: async () => {
+      acquired = true;
+      return {
+        sftpId: "sftp-pool",
+        poolKey: "host-1",
+        release: () => { released = true; },
+        discard: () => {},
+      };
+    },
+    startStreamTransfer: async (options) => {
+      assert.equal(options.targetSftpId, "sftp-pool");
+      return {};
+    },
+    onPatch: () => {},
+  });
+
+  assert.equal(result.success, true);
+  assert.equal(acquired, true);
+  assert.equal(released, true);
+});
+
+test("retry falls back to browse when pool acquire is unavailable", async () => {
+  const result = await retryExternalDragDropFileUpload(baseTask(), {
+    getBrowseSftpId: () => "sftp-live",
+    startStreamTransfer: async (options) => {
+      assert.equal(options.targetSftpId, "sftp-live");
+      return {};
+    },
+    onPatch: () => {},
+  });
+  assert.equal(result.success, true);
+});
+
+test("retry rolls parent to completed when all siblings succeed", async () => {
+  const patches: Array<{ id: string; updates: Partial<TransferTask> }> = [];
+  const result = await retryExternalDragDropFileUpload(baseTask(), {
+    getBrowseSftpId: () => "sftp-live",
+    startStreamTransfer: async () => ({}),
+    getTask: (id) => (
+      id === "folder-1"
+        ? baseTask({
+          id: "folder-1",
+          isDirectory: true,
+          status: "failed",
+          sourcePath: "/tmp/docs",
+          targetPath: "/remote/docs",
+          error: "1 of 2 files failed",
+          totalBytes: 2,
+          transferredBytes: 1,
+          parentTaskId: undefined,
+        })
+        : undefined
+    ),
+    getChildTasks: () => [
+      baseTask({ id: "child-1", status: "transferring" }),
+      baseTask({ id: "child-2", status: "completed", sourcePath: "/tmp/docs/b.txt" }),
+    ],
+    onPatch: (taskId, updates) => patches.push({ id: taskId, updates }),
+  });
+  assert.equal(result.success, true);
+  const parentPatch = patches.find((p) => p.id === "folder-1");
+  assert.ok(parentPatch);
+  assert.equal(parentPatch?.updates.status, "completed");
+});
+
+test("retry does not rollup a still-transferring progressive parent", async () => {
+  const patches: Array<{ id: string; updates: Partial<TransferTask> }> = [];
+  await retryExternalDragDropFileUpload(baseTask(), {
+    getBrowseSftpId: () => "sftp-live",
+    startStreamTransfer: async () => ({}),
+    getTask: (id) => (
+      id === "folder-1"
+        ? baseTask({
+          id: "folder-1",
+          isDirectory: true,
+          status: "transferring",
+          sourcePath: "/tmp/docs",
+          parentTaskId: undefined,
+        })
+        : undefined
+    ),
+    getChildTasks: () => [
+      baseTask({ id: "child-1", status: "transferring" }),
+      baseTask({ id: "child-2", status: "completed", sourcePath: "/tmp/docs/b.txt" }),
+    ],
+    onPatch: (taskId, updates) => patches.push({ id: taskId, updates }),
+  });
+  assert.equal(patches.some((p) => p.id === "folder-1"), false);
+});
+
+test("retry fails clearly when no sftp session can be opened", async () => {
+  const patches: Array<Partial<TransferTask>> = [];
+  const result = await retryExternalDragDropFileUpload(baseTask(), {
+    getBrowseSftpId: () => undefined,
+    startStreamTransfer: async () => {
+      throw new Error("should not start");
+    },
+    onPatch: (_id, updates) => patches.push(updates),
+  });
+
+  assert.equal(result.success, false);
+  assert.match(result.error || "", /No SFTP session/);
+  assert.equal(patches.at(-1)?.status, "failed");
+});
+
+test("stream error keeps the row failed with the backend message", async () => {
+  const patches: Array<Partial<TransferTask>> = [];
+  const result = await retryExternalDragDropFileUpload(baseTask(), {
+    getBrowseSftpId: () => "sftp-live",
+    startStreamTransfer: async () => ({ error: "Permission denied" }),
+    onPatch: (_id, updates) => patches.push(updates),
+  });
+
+  assert.equal(result.success, false);
+  assert.equal(result.error, "Permission denied");
+  assert.equal(patches.at(-1)?.status, "failed");
+  assert.equal(patches.at(-1)?.error, "Permission denied");
+});

application/state/sftp/externalDragDropRetry.ts

@@ -0,0 +1,267 @@
+/**
+ * Low-cost retry for progressive / external drag-drop file uploads.
+ *
+ * These rows use sourceConnectionId "external" and never have dual-pane
+ * endpoints, so the generic processTransfer retry path silently no-ops.
+ * Retry re-opens a single startStreamTransfer with the stored local path.
+ */
+
+import type { TransferTask } from "../../../domain/models";
+import type { TransferConnectionLease } from "./transferConnectionPool";
+import { isTransferCancelledFlag } from "./transferCancelLatch";
+
+export function isExternalDragDropFileUpload(
+  task: Pick<
+    TransferTask,
+    | "origin"
+    | "direction"
+    | "sourceConnectionId"
+    | "isDirectory"
+    | "sourcePath"
+    | "targetPath"
+    | "retryable"
+    | "status"
+  >,
+): boolean {
+  if (task.retryable === false) return false;
+  if (task.origin !== "drag-drop") return false;
+  if (task.direction !== "upload") return false;
+  if (task.sourceConnectionId !== "external") return false;
+  if (task.isDirectory) return false;
+  if (!task.sourcePath || task.sourcePath === "local") return false;
+  if (!task.targetPath) return false;
+  return task.status === "failed" || task.status === "cancelled" || task.status === "attention";
+}
+
+export type ExternalDragDropRetryDeps = {
+  getBrowseSftpId: (connectionId: string) => string | undefined;
+  acquireTransferSession?: (
+    hostId: string,
+    transferId: string,
+  ) => Promise<TransferConnectionLease>;
+  startStreamTransfer: (options: {
+    transferId: string;
+    sourcePath: string;
+    targetPath: string;
+    sourceType: "local";
+    targetType: "local" | "sftp";
+    targetSftpId?: string;
+    targetHostId?: string;
+    totalBytes?: number;
+    resumable?: boolean;
+    checkpointBytes?: number;
+  }) => Promise<{ error?: string; cancelled?: boolean } | undefined>;
+  clearPendingCancel?: (transferId: string) => Promise<unknown>;
+  cleanupArtifacts?: (task: TransferTask) => Promise<void>;
+  onPatch: (taskId: string, updates: Partial<TransferTask>) => void;
+  /** Live store lookup for terminal cancel races and completion bytes. */
+  getTask?: (taskId: string) => TransferTask | undefined;
+  /** Children of a progressive parent (for rollup after child success). */
+  getChildTasks?: (parentTaskId: string) => TransferTask[];
+};
+
+/**
+ * Restart a failed/cancelled external drag-drop file upload in place (same id).
+ * Returns true when the stream completed successfully.
+ */
+export async function retryExternalDragDropFileUpload(
+  task: TransferTask,
+  deps: ExternalDragDropRetryDeps,
+): Promise<{ success: boolean; error?: string }> {
+  if (!isExternalDragDropFileUpload(task)) {
+    return { success: false, error: "Not an external drag-drop file upload" };
+  }
+
+  try {
+    await deps.clearPendingCancel?.(task.id);
+  } catch {
+    // best-effort
+  }
+  try {
+    await deps.cleanupArtifacts?.(task);
+  } catch {
+    // best-effort
+  }
+
+  const targetIsLocal = task.targetConnectionId === "local" || !task.targetHostId;
+  let lease: TransferConnectionLease | null = null;
+  let targetSftpId: string | undefined;
+
+  try {
+    if (!targetIsLocal) {
+      // Prefer a dedicated pool session when hostId is known — same policy as
+      // progressive upload (do not pin the browse/tab session).
+      if (task.targetHostId && deps.acquireTransferSession) {
+        lease = await deps.acquireTransferSession(task.targetHostId, `${task.id}:retry`);
+        targetSftpId = lease.sftpId;
+      }
+      if (!targetSftpId) {
+        targetSftpId = deps.getBrowseSftpId(task.targetConnectionId);
+      }
+      if (!targetSftpId) {
+        const error = "No SFTP session available to retry this upload. Reconnect and try again.";
+        deps.onPatch(task.id, {
+          status: "failed",
+          error,
+          endTime: Date.now(),
+          speed: 0,
+        });
+        return { success: false, error };
+      }
+    }
+
+    deps.onPatch(task.id, {
+      status: "transferring",
+      error: undefined,
+      transferredBytes: 0,
+      checkpointBytes: 0,
+      speed: 0,
+      endTime: undefined,
+      phase: "transferring",
+      reconnectRequired: false,
+      pauseUnavailableReason: undefined,
+      startTime: Date.now(),
+    });
+
+    const result = await deps.startStreamTransfer({
+      transferId: task.id,
+      sourcePath: task.sourcePath,
+      targetPath: task.targetPath,
+      sourceType: "local",
+      targetType: targetIsLocal ? "local" : "sftp",
+      targetSftpId: targetIsLocal ? undefined : targetSftpId,
+      targetHostId: targetIsLocal ? undefined : task.targetHostId,
+      totalBytes: task.totalBytes > 0 ? task.totalBytes : undefined,
+      resumable: true,
+      checkpointBytes: 0,
+    });
+
+    // Late cancel can settle the row before this return; never resurrect it.
+    if (isTransferCancelledFlag(task.id) || result?.cancelled) {
+      deps.onPatch(task.id, {
+        status: "cancelled",
+        error: undefined,
+        endTime: Date.now(),
+        speed: 0,
+        phase: undefined,
+      });
+      return { success: false, error: "Transfer cancelled" };
+    }
+    if (result?.error) {
+      deps.onPatch(task.id, {
+        status: "failed",
+        error: result.error,
+        endTime: Date.now(),
+        speed: 0,
+        phase: undefined,
+      });
+      return { success: false, error: result.error };
+    }
+
+    const live = deps.getTask?.(task.id);
+    const completedBytes = Math.max(
+      live?.totalBytes ?? 0,
+      live?.transferredBytes ?? 0,
+      task.totalBytes,
+      0,
+    );
+    deps.onPatch(task.id, {
+      status: "completed",
+      error: undefined,
+      transferredBytes: completedBytes,
+      totalBytes: Math.max(live?.totalBytes ?? 0, task.totalBytes, completedBytes),
+      endTime: Date.now(),
+      speed: 0,
+      phase: undefined,
+    });
+
+    // Progressive parents finalize once with "N of M failed". After a child
+    // retry succeeds, re-roll the parent when no failed children remain.
+    if (task.parentTaskId && deps.getChildTasks) {
+      rollupParentAfterChildSuccess(task.parentTaskId, task.id, deps);
+    }
+
+    return { success: true };
+  } catch (error) {
+    const message = error instanceof Error ? error.message : String(error);
+    if (isTransferCancelledFlag(task.id) || /cancel/i.test(message)) {
+      deps.onPatch(task.id, {
+        status: "cancelled",
+        error: undefined,
+        endTime: Date.now(),
+        speed: 0,
+        phase: undefined,
+      });
+      return { success: false, error: "Transfer cancelled" };
+    }
+    deps.onPatch(task.id, {
+      status: "failed",
+      error: message,
+      endTime: Date.now(),
+      speed: 0,
+      phase: undefined,
+    });
+    if (lease && /session|sftp|disconnect|not found/i.test(message)) {
+      try { lease.discard(); } catch { /* best-effort */ }
+      lease = null;
+    }
+    return { success: false, error: message };
+  } finally {
+    try { lease?.release(); } catch { /* best-effort */ }
+  }
+}
+
+function rollupParentAfterChildSuccess(
+  parentTaskId: string,
+  completedChildId: string,
+  deps: ExternalDragDropRetryDeps,
+): void {
+  // Only re-roll parents that already finished the progressive walk as failed.
+  // Never promote a still-scanning/transferring parent mid-walk.
+  const parent = deps.getTask?.(parentTaskId);
+  if (
+    parent
+    && parent.status !== "failed"
+    && parent.status !== "attention"
+    && parent.status !== "cancelled"
+  ) {
+    return;
+  }
+  const children = deps.getChildTasks?.(parentTaskId) ?? [];
+  if (children.length === 0) return;
+  const stillFailed = children.some(
+    (child) =>
+      child.id !== completedChildId
+      && (child.status === "failed" || child.status === "attention"),
+  );
+  if (stillFailed) return;
+  const active = children.some(
+    (child) =>
+      child.id !== completedChildId
+      && (
+        child.status === "transferring"
+        || child.status === "pending"
+        || child.status === "queued"
+        || child.status === "pausing"
+        || child.status === "paused"
+      ),
+  );
+  if (active) return;
+  const completedCount = children.filter(
+    (child) => child.id === completedChildId || child.status === "completed",
+  ).length;
+  const total = Math.max(
+    Number(parent?.totalBytes) || 0,
+    children.length,
+    completedCount,
+  );
+  deps.onPatch(parentTaskId, {
+    status: "completed",
+    error: undefined,
+    transferredBytes: completedCount,
+    totalBytes: total,
+    speed: 0,
+    endTime: Date.now(),
+    phase: undefined,
+  });
+}

application/state/sftp/localSftpBookmarks.ts

@@ -0,0 +1,83 @@
+import { useCallback, useMemo, useSyncExternalStore } from "react";
+import type { SftpBookmark } from "../../../domain/models";
+import { localStorageAdapter } from "../../../infrastructure/persistence/localStorageAdapter";
+import { STORAGE_KEY_SFTP_LOCAL_BOOKMARKS } from "../../../infrastructure/config/storageKeys";
+import { createSftpBookmark } from "./bookmarkHelpers";
+
+type Listener = () => void;
+
+const listeners = new Set<Listener>();
+
+let snapshot: SftpBookmark[] =
+  localStorageAdapter.read<SftpBookmark[]>(STORAGE_KEY_SFTP_LOCAL_BOOKMARKS) ?? [];
+
+export function subscribeLocalSftpBookmarks(listener: Listener) {
+  listeners.add(listener);
+  return () => {
+    listeners.delete(listener);
+  };
+}
+
+export function getLocalSftpBookmarksSnapshot() {
+  return snapshot;
+}
+
+export function rehydrateLocalSftpBookmarks() {
+  snapshot = localStorageAdapter.read<SftpBookmark[]>(STORAGE_KEY_SFTP_LOCAL_BOOKMARKS) ?? [];
+  for (const listener of listeners) listener();
+}
+
+export function setLocalSftpBookmarks(
+  next: SftpBookmark[] | ((prev: SftpBookmark[]) => SftpBookmark[]),
+) {
+  snapshot = typeof next === "function" ? next(snapshot) : next;
+  localStorageAdapter.write(STORAGE_KEY_SFTP_LOCAL_BOOKMARKS, snapshot);
+  for (const listener of listeners) listener();
+}
+
+if (typeof window !== "undefined") {
+  window.addEventListener("storage", (event) => {
+    if (event.key === STORAGE_KEY_SFTP_LOCAL_BOOKMARKS) {
+      rehydrateLocalSftpBookmarks();
+    }
+  });
+}
+
+interface UseLocalSftpBookmarksParams {
+  currentPath: string | undefined;
+}
+
+export const useLocalSftpBookmarks = ({
+  currentPath,
+}: UseLocalSftpBookmarksParams) => {
+  const bookmarks = useSyncExternalStore(
+    subscribeLocalSftpBookmarks,
+    getLocalSftpBookmarksSnapshot,
+    getLocalSftpBookmarksSnapshot,
+  );
+
+  const isCurrentPathBookmarked = useMemo(
+    () => !!currentPath && bookmarks.some((b) => b.path === currentPath),
+    [currentPath, bookmarks],
+  );
+
+  const toggleBookmark = useCallback(() => {
+    if (!currentPath) return;
+    if (isCurrentPathBookmarked) {
+      setLocalSftpBookmarks((prev) => prev.filter((b) => b.path !== currentPath));
+    } else {
+      setLocalSftpBookmarks((prev) => [...prev, createSftpBookmark(currentPath)]);
+    }
+  }, [currentPath, isCurrentPathBookmarked]);
+
+  const deleteBookmark = useCallback((id: string) => {
+    setLocalSftpBookmarks((prev) => prev.filter((b) => b.id !== id));
+  }, []);
+
+  return {
+    bookmarks,
+    isCurrentPathBookmarked,
+    toggleBookmark,
+    deleteBookmark,
+  };
+};

application/state/sftp/sftpClipboardStore.ts

@@ -0,0 +1,124 @@
+/**
+ * SFTP Clipboard Store
+ * 
+ * Manages clipboard state for SFTP file operations (copy/cut/paste)
+ * This is a simple store that holds the clipboard state and operation type.
+ */
+
+import { useSyncExternalStore } from "react";
+
+type SftpClipboardOperation = "copy" | "cut";
+
+export interface SftpClipboardFile {
+  name: string;
+  isDirectory: boolean;
+}
+
+interface SftpClipboardState {
+  files: SftpClipboardFile[];
+  sourcePath: string;
+  sourceConnectionId: string;
+  sourceSide: "left" | "right";
+  operation: SftpClipboardOperation;
+}
+
+type ClipboardListener = () => void;
+
+let clipboardState: SftpClipboardState | null = null;
+const clipboardListeners = new Set<ClipboardListener>();
+
+const notifyListeners = () => {
+  clipboardListeners.forEach((listener) => listener());
+};
+
+export const sftpClipboardStore = {
+  getSnapshot: (): SftpClipboardState | null => clipboardState,
+  
+  subscribe: (listener: ClipboardListener) => {
+    clipboardListeners.add(listener);
+    return () => clipboardListeners.delete(listener);
+  },
+
+  /**
+   * Copy files to clipboard
+   */
+  copy: (
+    files: SftpClipboardFile[],
+    sourcePath: string,
+    sourceConnectionId: string,
+    sourceSide: "left" | "right"
+  ) => {
+    clipboardState = {
+      files,
+      sourcePath,
+      sourceConnectionId,
+      sourceSide,
+      operation: "copy",
+    };
+    notifyListeners();
+  },
+
+  /**
+   * Cut files to clipboard
+   */
+  cut: (
+    files: SftpClipboardFile[],
+    sourcePath: string,
+    sourceConnectionId: string,
+    sourceSide: "left" | "right"
+  ) => {
+    clipboardState = {
+      files,
+      sourcePath,
+      sourceConnectionId,
+      sourceSide,
+      operation: "cut",
+    };
+    notifyListeners();
+  },
+
+  /**
+   * Clear clipboard (called after paste for cut operation)
+   */
+  clear: () => {
+    clipboardState = null;
+    notifyListeners();
+  },
+
+  /**
+   * Update clipboard file list (used for partial cut transfers)
+   */
+  updateFiles: (files: SftpClipboardFile[]) => {
+    if (!clipboardState) return;
+    if (files.length === 0) {
+      clipboardState = null;
+    } else {
+      clipboardState = {
+        ...clipboardState,
+        files,
+      };
+    }
+    notifyListeners();
+  },
+
+  /**
+   * Check if there are files in the clipboard
+   */
+  hasFiles: (): boolean => clipboardState !== null && clipboardState.files.length > 0,
+
+  /**
+   * Get the clipboard state
+   */
+  get: (): SftpClipboardState | null => clipboardState,
+};
+
+/**
+ * React hook to subscribe to clipboard state changes
+ */
+export const useSftpClipboard = (): SftpClipboardState | null => {
+  return useSyncExternalStore(
+    sftpClipboardStore.subscribe,
+    sftpClipboardStore.getSnapshot,
+    sftpClipboardStore.getSnapshot
+  );
+};

application/state/sftp/sftpDialogActionStore.ts

@@ -0,0 +1,124 @@
+/**
+ * SFTP Dialog Action Store
+ * 
+ * Manages dialog action triggers for SFTP operations.
+ * This store allows keyboard shortcuts to trigger dialogs in the appropriate pane.
+ */
+
+import { useSyncExternalStore, useEffect } from "react";
+import { sftpFocusStore, SftpFocusedSide } from "./sftpFocusStore";
+
+type SftpDialogActionType = "rename" | "delete" | "newFolder" | "newFile" | null;
+
+interface SftpDialogAction {
+  type: SftpDialogActionType;
+  targetSide: SftpFocusedSide;
+  targetScopeId: string;
+  targetFiles?: string[]; // For rename (single file) or delete (multiple files)
+  timestamp: number; // To distinguish different triggers of the same action
+}
+
+type ActionListener = () => void;
+
+let dialogAction: SftpDialogAction | null = null;
+const actionListeners = new Set<ActionListener>();
+
+const notifyListeners = () => {
+  actionListeners.forEach((listener) => listener());
+};
+
+export const sftpDialogActionStore = {
+  getSnapshot: (): SftpDialogAction | null => dialogAction,
+
+  subscribe: (listener: ActionListener) => {
+    actionListeners.add(listener);
+    return () => actionListeners.delete(listener);
+  },
+
+  /**
+   * Trigger a dialog action
+   */
+  trigger: (type: SftpDialogActionType, targetScopeId: string, targetFiles?: string[]) => {
+    if (!type) {
+      dialogAction = null;
+    } else {
+      dialogAction = {
+        type,
+        targetSide: sftpFocusStore.getFocusedSide(),
+        targetScopeId,
+        targetFiles,
+        timestamp: Date.now(),
+      };
+    }
+    notifyListeners();
+  },
+
+  /**
+   * Clear the current action (called after a pane handles it)
+   */
+  clear: () => {
+    dialogAction = null;
+    notifyListeners();
+  },
+
+  /**
+   * Get the current action
+   */
+  get: (): SftpDialogAction | null => dialogAction,
+};
+
+/**
+ * React hook to subscribe to dialog action changes
+ */
+export const useSftpDialogAction = (): SftpDialogAction | null => {
+  return useSyncExternalStore(
+    sftpDialogActionStore.subscribe,
+    sftpDialogActionStore.getSnapshot,
+    sftpDialogActionStore.getSnapshot
+  );
+};
+
+/**
+ * React hook for a pane to respond to dialog actions
+ * Only the pane matching the targetSide will execute the callback
+ */
+export const useSftpDialogActionHandler = (
+  side: SftpFocusedSide,
+  scopeId: string,
+  handlers: {
+    onRename?: (fileName: string) => void;
+    onDelete?: (fileNames: string[]) => void;
+    onNewFolder?: () => void;
+    onNewFile?: () => void;
+  },
+  isActive = true
+) => {
+  const action = useSftpDialogAction();
+
+  useEffect(() => {
+    if (!action || action.targetSide !== side || action.targetScopeId !== scopeId || !isActive) return;
+
+    // Handle the action and clear it
+    switch (action.type) {
+      case "rename":
+        if (handlers.onRename && action.targetFiles?.[0]) {
+          handlers.onRename(action.targetFiles[0]);
+        }
+        break;
+      case "delete":
+        if (handlers.onDelete && action.targetFiles) {
+          handlers.onDelete(action.targetFiles);
+        }
+        break;
+      case "newFolder":
+        handlers.onNewFolder?.();
+        break;
+      case "newFile":
+        handlers.onNewFile?.();
+        break;
+    }
+
+    // Clear the action after handling
+    sftpDialogActionStore.clear();
+  }, [action, side, scopeId, handlers, isActive]);
+};

application/state/sftp/sftpFocusStore.ts

@@ -0,0 +1,54 @@
+/**
+ * SFTP Focused Pane Store
+ * 
+ * Tracks which SFTP pane (left or right) is currently focused.
+ * This is used to determine which pane should receive keyboard shortcut actions.
+ */
+
+import { useSyncExternalStore } from "react";
+
+export type SftpFocusedSide = "left" | "right";
+
+type FocusListener = () => void;
+
+let focusedSide: SftpFocusedSide = "left";
+const focusListeners = new Set<FocusListener>();
+
+const notifyListeners = () => {
+  focusListeners.forEach((listener) => listener());
+};
+
+export const sftpFocusStore = {
+  getSnapshot: (): SftpFocusedSide => focusedSide,
+
+  subscribe: (listener: FocusListener) => {
+    focusListeners.add(listener);
+    return () => focusListeners.delete(listener);
+  },
+
+  /**
+   * Set the focused side
+   */
+  setFocusedSide: (side: SftpFocusedSide) => {
+    if (focusedSide !== side) {
+      focusedSide = side;
+      notifyListeners();
+    }
+  },
+
+  /**
+   * Get the current focused side
+   */
+  getFocusedSide: (): SftpFocusedSide => focusedSide,
+};
+
+/**
+ * React hook to subscribe to focused side changes
+ */
+export const useSftpFocusedSide = (): SftpFocusedSide => {
+  return useSyncExternalStore(
+    sftpFocusStore.subscribe,
+    sftpFocusStore.getSnapshot,
+    sftpFocusStore.getSnapshot
+  );
+};

application/state/sftp/sftpHostViewModeStore.ts

@@ -0,0 +1,70 @@
+import { useCallback, useSyncExternalStore } from "react";
+import { localStorageAdapter } from "../../../infrastructure/persistence/localStorageAdapter";
+import { STORAGE_KEY_SFTP_HOST_VIEW_MODES } from "../../../infrastructure/config/storageKeys";
+
+// ── Shared external store for per-host SFTP view mode preferences ──
+
+type ViewMode = 'list' | 'tree';
+type Listener = () => void;
+
+const listeners = new Set<Listener>();
+
+let snapshot: Record<string, ViewMode> =
+    localStorageAdapter.read<Record<string, ViewMode>>(STORAGE_KEY_SFTP_HOST_VIEW_MODES) ?? {};
+
+function subscribe(listener: Listener) {
+    listeners.add(listener);
+    return () => { listeners.delete(listener); };
+}
+
+function getSnapshot() {
+    return snapshot;
+}
+
+function persist(next: Record<string, ViewMode>) {
+    snapshot = next;
+    localStorageAdapter.write(STORAGE_KEY_SFTP_HOST_VIEW_MODES, snapshot);
+    for (const l of listeners) l();
+}
+
+// Sync across windows/tabs via storage events
+if (typeof window !== 'undefined') {
+    window.addEventListener('storage', (e) => {
+        if (e.key !== STORAGE_KEY_SFTP_HOST_VIEW_MODES) return;
+        try {
+            snapshot = e.newValue
+                ? (JSON.parse(e.newValue) as Record<string, ViewMode>)
+                : {};
+        } catch {
+            snapshot = {};
+        }
+        for (const l of listeners) l();
+    });
+}
+
+/** Get the saved view mode for a specific host, or null if none saved. */
+export function getHostViewMode(hostId: string): ViewMode | null {
+    return snapshot[hostId] ?? null;
+}
+
+/** Save the view mode preference for a specific host. */
+export function setHostViewMode(hostId: string, mode: ViewMode): void {
+    if (snapshot[hostId] === mode) return;
+    persist({ ...snapshot, [hostId]: mode });
+}
+
+// ── Hook ──
+
+export function useSftpHostViewMode(hostId: string | undefined) {
+    const store = useSyncExternalStore(subscribe, getSnapshot, getSnapshot);
+
+    const mode: ViewMode | null = hostId ? (store[hostId] ?? null) : null;
+
+    const setMode = useCallback((newMode: ViewMode) => {
+        if (hostId) {
+            setHostViewMode(hostId, newMode);
+        }
+    }, [hostId]);
+
+    return { hostViewMode: mode, setHostViewMode: setMode };
+}

application/state/sftp/sftpTreeSelectionStore.ts

@@ -0,0 +1,153 @@
+import { useCallback, useSyncExternalStore } from "react";
+
+export interface SftpTreeSelectionItem {
+  path: string;
+  name: string;
+  isDirectory: boolean;
+  sourcePath: string;
+}
+
+interface SftpTreeSelectionState {
+  visibleItems: SftpTreeSelectionItem[];
+  visibleItemsByPath: Map<string, SftpTreeSelectionItem>;
+  visibleIndexByPath: Map<string, number>;
+  visiblePathsSet: Set<string>;
+  selectedPaths: Set<string>;
+}
+
+const EMPTY_PATHS = new Set<string>();
+
+const EMPTY_STATE: SftpTreeSelectionState = {
+  visibleItems: [],
+  visibleItemsByPath: new Map(),
+  visibleIndexByPath: new Map(),
+  visiblePathsSet: new Set(),
+  selectedPaths: EMPTY_PATHS,
+};
+
+type Listener = () => void;
+
+const paneStates = new Map<string, SftpTreeSelectionState>();
+const paneListeners = new Map<string, Set<Listener>>();
+
+const notifyPaneListeners = (paneId: string) => {
+  paneListeners.get(paneId)?.forEach((listener) => listener());
+};
+
+const getPaneState = (paneId: string): SftpTreeSelectionState =>
+  paneStates.get(paneId) ?? EMPTY_STATE;
+
+const setPaneState = (
+  paneId: string,
+  updater: (state: SftpTreeSelectionState) => SftpTreeSelectionState,
+) => {
+  const prev = getPaneState(paneId);
+  const next = updater(prev);
+  if (next === prev) return;
+  if (next.visibleItems.length === 0 && next.selectedPaths.size === 0) {
+    paneStates.delete(paneId);
+  } else {
+    paneStates.set(paneId, next);
+  }
+  notifyPaneListeners(paneId);
+};
+
+export const sftpTreeSelectionStore = {
+  getPaneState,
+
+  getSelectedItems: (paneId: string): SftpTreeSelectionItem[] => {
+    const state = getPaneState(paneId);
+    const result: SftpTreeSelectionItem[] = [];
+    for (const path of state.selectedPaths) {
+      const item = state.visibleItemsByPath.get(path);
+      if (item) result.push(item);
+    }
+    return result;
+  },
+
+  setVisibleItems: (paneId: string, visibleItems: SftpTreeSelectionItem[]) => {
+    const visibleItemsByPath = new Map<string, SftpTreeSelectionItem>();
+    const visibleIndexByPath = new Map<string, number>();
+    const visiblePathsSet = new Set(visibleItems.map((item) => item.path));
+    visibleItems.forEach((item, index) => {
+      visibleItemsByPath.set(item.path, item);
+      visibleIndexByPath.set(item.path, index);
+    });
+    setPaneState(paneId, (state) => {
+      const newSelected = new Set([...state.selectedPaths].filter((p) => visiblePathsSet.has(p)));
+      const changed =
+        newSelected.size !== state.selectedPaths.size ||
+        [...newSelected].some((p) => !state.selectedPaths.has(p));
+      return {
+        visibleItems,
+        visibleItemsByPath,
+        visibleIndexByPath,
+        visiblePathsSet,
+        selectedPaths: changed ? newSelected : state.selectedPaths,
+      };
+    });
+  },
+
+  setSelection: (paneId: string, selectedPaths: Iterable<string>) => {
+    setPaneState(paneId, (state) => ({
+      ...state,
+      selectedPaths: new Set(Array.from(selectedPaths).filter((path) => state.visiblePathsSet.has(path))),
+    }));
+  },
+
+  clearSelection: (paneId: string) => {
+    setPaneState(paneId, (state) => ({ ...state, selectedPaths: EMPTY_PATHS }));
+  },
+
+  clearAllExcept: (paneIdsToKeep?: Iterable<string>) => {
+    const keep = new Set(paneIdsToKeep ?? []);
+    Array.from(paneStates.keys()).forEach((paneId) => {
+      if (keep.has(paneId)) return;
+      setPaneState(paneId, (state) => {
+        if (state.selectedPaths.size === 0) return state;
+        return { ...state, selectedPaths: EMPTY_PATHS };
+      });
+    });
+  },
+
+  selectAllVisible: (paneId: string) => {
+    setPaneState(paneId, (state) => ({
+      ...state,
+      selectedPaths: new Set(
+        state.visibleItems.map((item) => item.path),
+      ),
+    }));
+  },
+
+  clearPane: (paneId: string) => {
+    if (!paneStates.has(paneId)) return;
+    paneStates.delete(paneId);
+    notifyPaneListeners(paneId);
+  },
+
+  subscribe: (paneId: string, listener: Listener) => {
+    const listeners = paneListeners.get(paneId) ?? new Set<Listener>();
+    listeners.add(listener);
+    paneListeners.set(paneId, listeners);
+    return () => {
+      const current = paneListeners.get(paneId);
+      if (!current) return;
+      current.delete(listener);
+      if (current.size === 0) {
+        paneListeners.delete(paneId);
+      }
+    };
+  },
+};
+
+export const useSftpTreeSelectionState = (paneId: string): SftpTreeSelectionState => {
+  const subscribe = useCallback(
+    (listener: () => void) => sftpTreeSelectionStore.subscribe(paneId, listener),
+    [paneId],
+  );
+  return useSyncExternalStore(
+    subscribe,
+    () => sftpTreeSelectionStore.getPaneState(paneId),
+    () => sftpTreeSelectionStore.getPaneState(paneId),
+  );
+};

application/state/sftp/transferConcurrency.test.ts

@@ -2,8 +2,13 @@ import test from "node:test";
 import assert from "node:assert/strict";
 
 import {
+  DEFAULT_SFTP_DIRECTORY_LISTING_CONCURRENCY,
   DEFAULT_SFTP_FILE_TRANSFER_CONCURRENCY,
+  DEFAULT_SFTP_SKIP_UNCHANGED,
+  resolveSftpDirectoryListingConcurrency,
+  resolveSftpSkipUnchangedEnabled,
   resolveSftpTransferConcurrency,
+  runBoundedConcurrency,
   runSftpTransferWorkers,
 } from "./transferConcurrency";
 
@@ -12,6 +17,20 @@ test("defaults folder file transfers to two concurrent files", () => {
   assert.equal(DEFAULT_SFTP_FILE_TRANSFER_CONCURRENCY, 2);
 });
 
+test("defaults directory listing fanout to four concurrent readdirs", () => {
+  assert.equal(
+    resolveSftpDirectoryListingConcurrency(() => null),
+    DEFAULT_SFTP_DIRECTORY_LISTING_CONCURRENCY,
+  );
+  assert.equal(DEFAULT_SFTP_DIRECTORY_LISTING_CONCURRENCY, 4);
+});
+
+test("defaults skip-unchanged to enabled", () => {
+  assert.equal(resolveSftpSkipUnchangedEnabled(() => null), DEFAULT_SFTP_SKIP_UNCHANGED);
+  assert.equal(DEFAULT_SFTP_SKIP_UNCHANGED, true);
+  assert.equal(resolveSftpSkipUnchangedEnabled(() => false), false);
+});
+
 test("keeps explicit folder transfer concurrency within the supported range", () => {
   assert.equal(resolveSftpTransferConcurrency(() => 1), 1);
   assert.equal(resolveSftpTransferConcurrency(() => 16), 16);
@@ -19,6 +38,19 @@ test("keeps explicit folder transfer concurrency within the supported range", ()
   assert.equal(resolveSftpTransferConcurrency(() => 17), DEFAULT_SFTP_FILE_TRANSFER_CONCURRENCY);
 });
 
+test("keeps directory listing concurrency within the supported range", () => {
+  assert.equal(resolveSftpDirectoryListingConcurrency(() => 1), 1);
+  assert.equal(resolveSftpDirectoryListingConcurrency(() => 8), 8);
+  assert.equal(
+    resolveSftpDirectoryListingConcurrency(() => 0),
+    DEFAULT_SFTP_DIRECTORY_LISTING_CONCURRENCY,
+  );
+  assert.equal(
+    resolveSftpDirectoryListingConcurrency(() => 9),
+    DEFAULT_SFTP_DIRECTORY_LISTING_CONCURRENCY,
+  );
+});
+
 test("limits default multi-file transfer scheduling to two concurrent workers", async () => {
   let active = 0;
   let maxActive = 0;
@@ -33,6 +65,106 @@ test("limits default multi-file transfer scheduling to two concurrent workers",
   assert.equal(maxActive, 2);
 });
 
+test("runBoundedConcurrency respects an explicit limit", async () => {
+  let active = 0;
+  let maxActive = 0;
+  await runBoundedConcurrency([1, 2, 3, 4, 5, 6], 3, async () => {
+    active += 1;
+    maxActive = Math.max(maxActive, active);
+    await new Promise((resolve) => setTimeout(resolve, 5));
+    active -= 1;
+  });
+  assert.equal(maxActive, 3);
+});
+
+test("runBoundedConcurrency drains siblings and stops new claims after an error", async () => {
+  const started: number[] = [];
+  const finished: number[] = [];
+  let releaseSlow!: () => void;
+  const slowGate = new Promise<void>((resolve) => {
+    releaseSlow = resolve;
+  });
+
+  const run = runBoundedConcurrency([0, 1, 2, 3, 4], 2, async (item) => {
+    started.push(item);
+    if (item === 0) {
+      await new Promise((resolve) => setTimeout(resolve, 10));
+      throw new Error("boom");
+    }
+    if (item === 1) {
+      await slowGate;
+    }
+    finished.push(item);
+  });
+
+  await new Promise((resolve) => setTimeout(resolve, 30));
+
+  let settledWhileSiblingRunning = false;
+  await Promise.race([
+    run.then(
+      () => {
+        settledWhileSiblingRunning = true;
+      },
+      () => {
+        settledWhileSiblingRunning = true;
+      },
+    ),
+    new Promise((resolve) => setTimeout(resolve, 5)),
+  ]);
+  assert.equal(
+    settledWhileSiblingRunning,
+    false,
+    "must wait for in-flight siblings before propagating the error",
+  );
+  assert.ok(started.includes(1));
+  assert.equal(finished.includes(1), false);
+
+  releaseSlow();
+  await assert.rejects(run, /boom/);
+  assert.ok(finished.includes(1), "in-flight sibling must finish before reject");
+  assert.deepEqual(
+    [...started].sort((a, b) => a - b),
+    [0, 1],
+    "must not claim additional queue items after the first error",
+  );
+});
+
+test("runSftpTransferWorkers drains siblings and stops new claims after an error", async () => {
+  const started: number[] = [];
+  const finished: number[] = [];
+  let releaseSlow!: () => void;
+  const slowGate = new Promise<void>((resolve) => {
+    releaseSlow = resolve;
+  });
+
+  const run = runSftpTransferWorkers([0, 1, 2, 3, 4], () => 2, async (item) => {
+    started.push(item);
+    if (item === 0) {
+      await new Promise((resolve) => setTimeout(resolve, 10));
+      throw new Error("session lost");
+    }
+    if (item === 1) {
+      await slowGate;
+    }
+    finished.push(item);
+  });
+
+  await new Promise((resolve) => setTimeout(resolve, 30));
+  let settledEarly = false;
+  await Promise.race([
+    run.then(
+      () => { settledEarly = true; },
+      () => { settledEarly = true; },
+    ),
+    new Promise((resolve) => setTimeout(resolve, 5)),
+  ]);
+  assert.equal(settledEarly, false);
+  releaseSlow();
+  await assert.rejects(run, /session lost/);
+  assert.ok(finished.includes(1));
+  assert.deepEqual([...started].sort((a, b) => a - b), [0, 1]);
+});
+
 test("beforeClaim runs before claiming the next queue index", async () => {
   const events: string[] = [];
   let paused = true;

application/state/sftp/transferConcurrency.ts

@@ -2,6 +2,20 @@ export const DEFAULT_SFTP_FILE_TRANSFER_CONCURRENCY = 2;
 export const MIN_SFTP_FILE_TRANSFER_CONCURRENCY = 1;
 export const MAX_SFTP_FILE_TRANSFER_CONCURRENCY = 16;
 
+/**
+ * Bounded parallel directory listings while walking a folder tree.
+ * SFTP has no recursive LIST; FileZilla/WinSCP still walk one dir at a time on
+ * a single control channel. We pipeline several OPENDIR/READDIR requests so
+ * wide trees discover total file counts much faster without a second full scan.
+ * Keep this modest - listing shares the transfer SFTP session with file I/O.
+ */
+export const DEFAULT_SFTP_DIRECTORY_LISTING_CONCURRENCY = 4;
+export const MIN_SFTP_DIRECTORY_LISTING_CONCURRENCY = 1;
+export const MAX_SFTP_DIRECTORY_LISTING_CONCURRENCY = 8;
+
+/** Default on: skip size+mtime matches like rsync's generator. */
+export const DEFAULT_SFTP_SKIP_UNCHANGED = true;
+
 export function resolveSftpTransferConcurrency(readStoredValue: () => number | null | undefined): number {
   const stored = readStoredValue();
   return stored != null &&
@@ -11,6 +25,24 @@ export function resolveSftpTransferConcurrency(readStoredValue: () => number | n
     : DEFAULT_SFTP_FILE_TRANSFER_CONCURRENCY;
 }
 
+export function resolveSftpDirectoryListingConcurrency(
+  readStoredValue?: () => number | null | undefined,
+): number {
+  const stored = readStoredValue?.();
+  return stored != null &&
+    stored >= MIN_SFTP_DIRECTORY_LISTING_CONCURRENCY &&
+    stored <= MAX_SFTP_DIRECTORY_LISTING_CONCURRENCY
+    ? stored
+    : DEFAULT_SFTP_DIRECTORY_LISTING_CONCURRENCY;
+}
+
+export function resolveSftpSkipUnchangedEnabled(
+  readStoredValue: () => boolean | null | undefined,
+): boolean {
+  const stored = readStoredValue();
+  return stored == null ? DEFAULT_SFTP_SKIP_UNCHANGED : stored;
+}
+
 export async function runSftpTransferWorkers<T>(
   items: T[],
   readStoredConcurrency: () => number | null | undefined,
@@ -26,17 +58,27 @@ export async function runSftpTransferWorkers<T>(
 ): Promise<void> {
   const concurrency = resolveSftpTransferConcurrency(readStoredConcurrency);
   let nextIndex = 0;
+  let failed = false;
+  let firstError: unknown;
 
   const runNext = async () => {
-    while (nextIndex < items.length) {
-      // Wait BEFORE claiming so pause does not leave a claimed-but-not-started
-      // index that arms as soon as soft-drain finishes the previous file.
-      if (options?.beforeClaim) {
-        await options.beforeClaim();
+    while (!failed && nextIndex < items.length) {
+      try {
+        // Wait BEFORE claiming so pause does not leave a claimed-but-not-started
+        // index that arms as soon as soft-drain finishes the previous file.
+        if (options?.beforeClaim) {
+          await options.beforeClaim();
+        }
+        if (failed || nextIndex >= items.length) return;
+        const index = nextIndex++;
+        await worker(items[index], index);
+      } catch (err) {
+        if (!failed) {
+          failed = true;
+          firstError = err;
+        }
+        return;
       }
-      if (nextIndex >= items.length) return;
-      const index = nextIndex++;
-      await worker(items[index], index);
     }
   };
 
@@ -44,5 +86,47 @@ export async function runSftpTransferWorkers<T>(
     { length: Math.min(concurrency, items.length) },
     () => runNext(),
   );
+  // Settle every started worker before propagating - Promise.all would reject
+  // while siblings keep claiming files after the caller releases leases.
   await Promise.all(workers);
+  if (failed) throw firstError;
+}
+
+/** Run workers over a queue with an explicit concurrency (not settings-backed). */
+export async function runBoundedConcurrency<T>(
+  items: T[],
+  concurrency: number,
+  worker: (item: T, index: number) => Promise<void>,
+  options?: {
+    beforeClaim?: () => Promise<void>;
+  },
+): Promise<void> {
+  const limit = Math.max(1, Math.min(Math.floor(concurrency) || 1, items.length || 1));
+  if (items.length === 0) return;
+  let nextIndex = 0;
+  let failed = false;
+  let firstError: unknown;
+  const runNext = async () => {
+    while (!failed && nextIndex < items.length) {
+      try {
+        if (options?.beforeClaim) {
+          await options.beforeClaim();
+        }
+        // Re-check after beforeClaim: a sibling may have failed while we waited.
+        if (failed || nextIndex >= items.length) return;
+        const index = nextIndex++;
+        await worker(items[index], index);
+      } catch (err) {
+        if (!failed) {
+          failed = true;
+          firstError = err;
+        }
+        return;
+      }
+    }
+  };
+  // Settle every started worker before propagating - Promise.all would reject
+  // while siblings keep claiming directories / transferring after the caller cleans up.
+  await Promise.all(Array.from({ length: Math.min(limit, items.length) }, () => runNext()));
+  if (failed) throw firstError;
 }

application/state/sftp/transferDirectoryOps.discovery.test.tsx

@@ -146,7 +146,9 @@ test("directory transfer discovers each directory once with bounded listing conc
     assert.equal(listCalls.size, directoryCount + 1);
     assert.ok(Array.from(listCalls.values()).every((count) => count === 1));
     assert.equal(listCalls.has("/source/loop"), false, "canonical symlink cycles must not be listed");
-    assert.equal(maxActiveListings, 1);
+    // Interleaved walk processes sibling subdirectories sequentially so resume
+    // manifests stay deterministic (no full-tree pre-scan fan-out).
+    assert.equal(maxActiveListings, 1, `expected sequential listings, got ${maxActiveListings}`);
     assert.equal(tasks.find((task) => task.id === root.id)?.totalBytes, directoryCount);
   } finally {
     await act(async () => {

application/state/sftp/transferDirectoryOps.ts

@@ -9,11 +9,20 @@ import {
   type SftpDirectoryTraversalBudget,
   shouldFollowSftpSymlinkDirectory,
 } from "../../../domain/sftpDirectoryCheckpoint";
-import { STORAGE_KEY_SFTP_TRANSFER_CONCURRENCY } from "../../../infrastructure/config/storageKeys";
+import { isUnchangedTransferCandidate } from "../../../domain/sftpTransferSkip";
+import {
+  STORAGE_KEY_SFTP_SKIP_UNCHANGED,
+  STORAGE_KEY_SFTP_TRANSFER_CONCURRENCY,
+} from "../../../infrastructure/config/storageKeys";
 import { localStorageAdapter } from "../../../infrastructure/persistence/localStorageAdapter";
 import { netcattyBridge } from "../../../infrastructure/services/netcattyBridge";
 import { logger } from "../../../lib/logger";
-import { runSftpTransferWorkers } from "./transferConcurrency";
+import {
+  DEFAULT_SFTP_DIRECTORY_LISTING_CONCURRENCY,
+  resolveSftpDirectoryListingConcurrency,
+  resolveSftpSkipUnchangedEnabled,
+  runSftpTransferWorkers,
+} from "./transferConcurrency";
 import { getSftpTransferResourceKeys, globalSftpTransferScheduler } from "./globalTransferScheduler";
 import { resolveDedicatedStreamEndpointIds } from "../../../domain/sftpDedicatedStreamPolicy";
 import { isSessionError } from "./errors";
@@ -31,6 +40,49 @@ import {
 import { isTransferOrRootCancelled } from "./transferCancelLatch";
 import { joinPath, joinTransferTargetPath } from "./utils";
 
+function createDirectoryListingGate(concurrency = DEFAULT_SFTP_DIRECTORY_LISTING_CONCURRENCY) {
+  const limit = Math.max(1, Math.floor(concurrency) || 1);
+  let active = 0;
+  const waiters: Array<() => void> = [];
+  const acquire = async () => {
+    if (active < limit) {
+      active += 1;
+      return;
+    }
+    await new Promise<void>((resolve) => {
+      waiters.push(() => {
+        active += 1;
+        resolve();
+      });
+    });
+  };
+  const release = () => {
+    active = Math.max(0, active - 1);
+    const next = waiters.shift();
+    if (next) next();
+  };
+  return {
+    get active() {
+      return active;
+    },
+    async run<T>(fn: () => Promise<T>): Promise<T> {
+      await acquire();
+      try {
+        return await fn();
+      } finally {
+        release();
+      }
+    },
+  };
+}
+
+type DirectoryDiscoveryProgress = {
+  discoveredFiles: number;
+  nextEntryIndex: number;
+  /** Tree-wide semaphore so nested parallel walks cannot multiply listings. */
+  listingGate?: ReturnType<typeof createDirectoryListingGate>;
+};
+
 function isCancelledLocalOrGlobal(
   cancelledTasksRef: { current: Set<string> },
   rootTaskId: string,
@@ -45,6 +97,40 @@ function isCancelledLocalOrGlobal(
   return false;
 }
 
+function readSkipUnchangedEnabled(): boolean {
+  return resolveSftpSkipUnchangedEnabled(() => localStorageAdapter.readBoolean(STORAGE_KEY_SFTP_SKIP_UNCHANGED));
+}
+
+async function tryStatTransferPath(
+  filePath: string,
+  isLocal: boolean,
+  sftpId: string | null,
+  encoding: SftpFilenameEncoding,
+): Promise<{ size: number; lastModified: number; type: string } | null> {
+  try {
+    if (isLocal) {
+      const stat = await netcattyBridge.get()?.statLocal?.(filePath);
+      if (!stat || stat.type === "directory") return null;
+      return { size: Number(stat.size) || 0, lastModified: Number(stat.lastModified) || 0, type: stat.type };
+    }
+    if (!sftpId) return null;
+    const stat = await netcattyBridge.get()?.statSftp?.(sftpId, filePath, encoding);
+    if (!stat || stat.type === "directory") return null;
+    return { size: Number(stat.size) || 0, lastModified: Number(stat.lastModified) || 0, type: stat.type };
+  } catch {
+    return null;
+  }
+}
+
+async function tryStatTransferTarget(
+  targetPath: string,
+  targetIsLocal: boolean,
+  targetSftpId: string | null,
+  targetEncoding: SftpFilenameEncoding,
+): Promise<{ size: number; lastModified: number; type: string } | null> {
+  return tryStatTransferPath(targetPath, targetIsLocal, targetSftpId, targetEncoding);
+}
+
 export type AcquireTransferSessionFn = (
   hostId: string,
   transferId: string,
@@ -449,7 +535,7 @@ export function useSftpDirectoryTransferOps({
     sameHost?: boolean,
     symlinkDepth = 0,
     followSymlinks = false, // Only true for downloadToLocal — uploads/copies treat symlinks as files
-    discoveryProgress?: { discoveredFiles: number; nextEntryIndex: number },
+    discoveryProgress?: DirectoryDiscoveryProgress,
     traversalBudget?: SftpDirectoryTraversalBudget,
   ) => {
     // Check if task or root task was cancelled before starting
@@ -457,8 +543,20 @@ export function useSftpDirectoryTransferOps({
       throw new Error("Transfer cancelled");
     }
 
+    // Always interleave discovery with transfer (rsync --inc-recursive style).
+    // Full-tree pre-scan was removed: non-compressed folder uploads start bytes
+    // as soon as each directory is listed; compressed upload is a separate path.
+    // UI should treat totalBytes as "discovered so far", not a fixed grand total.
     let totalErrors = 0;
-    const progress = discoveryProgress ?? { discoveredFiles: 0, nextEntryIndex: 0 };
+    const progress = discoveryProgress ?? {
+      discoveredFiles: 0,
+      nextEntryIndex: 0,
+      listingGate: createDirectoryListingGate(resolveSftpDirectoryListingConcurrency()),
+    };
+    if (!progress.listingGate) {
+      progress.listingGate = createDirectoryListingGate(resolveSftpDirectoryListingConcurrency());
+    }
+    const listingGate = progress.listingGate;
     const traversal = traversalBudget ?? createSftpDirectoryTraversalBudget();
     let claimedCanonicalPath: string | null = null;
     let regularFiles: SftpFileEntry[] = [];
@@ -500,13 +598,16 @@ export function useSftpDirectoryTransferOps({
       }
 
       let files: SftpFileEntry[];
-      if (sourceIsLocal) {
-        files = await listLocalFiles(task.sourcePath);
-      } else if (sourceSftpId) {
-        files = await listRemoteFiles(sourceSftpId, task.sourcePath, sourceEncoding);
-      } else {
+      // Tree-wide listing gate: parallel siblings share one budget.
+      files = await listingGate.run(async () => {
+        if (sourceIsLocal) {
+          return listLocalFiles(task.sourcePath);
+        }
+        if (sourceSftpId) {
+          return listRemoteFiles(sourceSftpId, task.sourcePath, sourceEncoding);
+        }
         throw new Error("No source connection");
-      }
+      });
 
       // Filter both "." and ".." — some SFTP servers include "." in readdir
       const filtered = files.filter((f) => f.name !== ".." && f.name !== ".");
@@ -536,26 +637,25 @@ export function useSftpDirectoryTransferOps({
       regularFiles.sort((left, right) => left.name.localeCompare(right.name));
 
       // Directory progress is discovered by the same traversal that performs
-      // the transfer. This avoids a second full-tree list pass and lets the UI
-      // grow the total incrementally without flooding the server at startup.
+      // the transfer (single pass - no separate countDirectoryFiles walk).
+      // Process subdirectories sequentially so directoryEntryIndex / manifest
+      // order stay deterministic for resume, and sibling symlink aliases can
+      // claim the same canonical path after the prior branch releases.
       progress.discoveredFiles += regularFiles.length;
       setTransfers((prev) => prev.map((candidate) => candidate.id === rootTaskId
         ? {
             ...candidate,
             totalBytes: Math.max(progress.discoveredFiles, candidate.transferredBytes),
+            // Keep scanning only until the first file completes; later lists must
+            // not flip an in-progress folder bar back to indeterminate thrash.
+            ...(candidate.transferredBytes <= 0 ? { phase: "scanning" as const } : null),
           }
         : candidate));
 
-      // Process subdirectories sequentially to avoid unbounded concurrent SFTP
-      // requests from nested Promise.all + worker pools across the tree.
-      // File-level concurrency within each directory is still governed by the
-      // shared SFTP transfer worker scheduler below.
       for (const dir of dirs) {
         if (cancelledTasksRef.current.has(task.id) || cancelledTasksRef.current.has(rootTaskId)) {
           throw new Error("Transfer cancelled");
         }
-        // Pause between subfolders — otherwise the walk enters the next tree while
-        // the user thinks the whole folder transfer is paused.
         await waitWhileTransferPaused(rootTaskId);
 
         const childTask: TransferTask = {
@@ -571,7 +671,7 @@ export function useSftpDirectoryTransferOps({
         };
 
         const isSymlink = dir.type === "symlink";
-        const subdirErrors = await transferDirectory(
+        totalErrors += await transferDirectory(
           childTask,
           sourceSftpId,
           targetSftpId,
@@ -586,7 +686,6 @@ export function useSftpDirectoryTransferOps({
           progress,
           traversal,
         );
-        totalErrors += subdirErrors;
       }
     } finally {
       // Release on success, cancellation, and traversal errors.
@@ -597,6 +696,12 @@ export function useSftpDirectoryTransferOps({
 
     // Transfer files in parallel with concurrency limit
     if (regularFiles.length > 0) {
+      setTransfers((prev) => prev.map((candidate) => candidate.id === rootTaskId
+        ? {
+            ...candidate,
+            phase: "transferring",
+          }
+        : candidate));
       const errors: Error[] = [];
       // If the SFTP session dies mid-directory, stop queueing more files
       // (remaining workers will still finish their current item).
@@ -616,8 +721,10 @@ export function useSftpDirectoryTransferOps({
           const fileSize = getEntrySize(file);
           const sourcePath = joinPath(task.sourcePath, file.name);
           const targetPath = joinTransferTargetPath(task.targetPath, file.name);
+          let transferSize = fileSize;
+          let transferLastModified = file.lastModified;
           const directoryEntryIndex = directoryEntryBase + fileIndex;
-          const directoryEntryIdentity = createDirectoryEntryIdentity({
+          let directoryEntryIdentity = createDirectoryEntryIdentity({
             sourcePath,
             targetPath,
             size: fileSize,
@@ -642,6 +749,104 @@ export function useSftpDirectoryTransferOps({
           if (isPauseLatched(rootTaskId)) {
             await waitWhileTransferPaused(rootTaskId);
           }
+
+          // Symlink listing attrs are the link node; transfer follows target bytes.
+          // For regular files, re-stat so skip and transfer use current size/mtime
+          // (Codex P1: listing attrs can go stale during a long interleaved walk).
+          let freshSourceOk = false;
+          if (file.type !== "symlink") {
+            const freshSource = await tryStatTransferPath(
+              sourcePath,
+              sourceIsLocal,
+              sourceSftpId,
+              sourceEncoding,
+            );
+            if (freshSource && freshSource.type !== "directory") {
+              transferSize = freshSource.size;
+              transferLastModified = freshSource.lastModified;
+              directoryEntryIdentity = createDirectoryEntryIdentity({
+                sourcePath,
+                targetPath,
+                size: transferSize,
+                lastModified: transferLastModified,
+              });
+              freshSourceOk = true;
+            } else {
+              // Do not pass stale listing size as an explicit snapshot: the
+              // dedicated transfer session may still read a grown file (Codex P2).
+              // Child totalBytes 0 is omitted at startStreamTransfer via
+              // `|| undefined`, so the bridge re-stats instead of truncating.
+              transferSize = 0;
+              transferLastModified = 0;
+            }
+          }
+
+          const skipUnchanged = readSkipUnchangedEnabled()
+            && !task.replaceExistingTarget
+            && !String(task.targetPath).includes(".netcatty-");
+          // Missing fresh metadata must not fall back to listing attrs for skip.
+          if (skipUnchanged && file.type !== "symlink" && freshSourceOk) {
+            const existing = await tryStatTransferTarget(
+              targetPath,
+              targetIsLocal,
+              targetSftpId,
+              targetEncoding,
+            );
+            if (
+              existing
+              && existing.type !== "directory"
+              && isUnchangedTransferCandidate(
+                { size: transferSize, lastModified: transferLastModified, mtimeUnit: "ms" },
+                { size: existing.size, lastModified: existing.lastModified, mtimeUnit: "ms" },
+              )
+            ) {
+              const skippedId = persistedChild?.id ?? crypto.randomUUID();
+              setTransfers((prev) => {
+                const hasChild = prev.some((row) => row.id === skippedId);
+                const base = hasChild
+                  ? prev.map((row) => row.id === skippedId
+                    ? {
+                        ...row,
+                        status: "completed" as TransferStatus,
+                        transferredBytes: transferSize,
+                        totalBytes: transferSize,
+                        endTime: Date.now(),
+                        speed: 0,
+                        error: undefined,
+                      }
+                    : row)
+                  : [...prev, {
+                      ...task,
+                      id: skippedId,
+                      fileName: file.name,
+                      originalFileName: file.name,
+                      sourcePath,
+                      targetPath,
+                      isDirectory: false,
+                      progressMode: "bytes" as const,
+                      parentTaskId: rootTaskId,
+                      totalBytes: transferSize,
+                      transferredBytes: transferSize,
+                      sourceLastModified: transferLastModified,
+                      directoryEntryIndex,
+                      directoryEntryIdentity,
+                      status: "completed" as TransferStatus,
+                      speed: 0,
+                      startTime: Date.now(),
+                      endTime: Date.now(),
+                    }];
+                return base.map((row) => {
+                  if (row.id !== rootTaskId) return row;
+                  if (row.status === "paused" || row.status === "pausing" || isPauseLatched(rootTaskId)) {
+                    return { ...row, speed: 0 };
+                  }
+                  return { ...row, transferredBytes: row.transferredBytes + 1 };
+                });
+              });
+              return;
+            }
+          }
+
           const fileId = persistedChild?.id ?? crypto.randomUUID();
 
           // Track child ID outside React state for immediate cancellation visibility
@@ -661,11 +866,11 @@ export function useSftpDirectoryTransferOps({
             isDirectory: false,
             progressMode: "bytes",
             parentTaskId: rootTaskId,
-            totalBytes: fileSize,
-            sourceLastModified: file.lastModified,
+            totalBytes: transferSize,
+            sourceLastModified: transferLastModified || undefined,
             directoryEntryIndex,
             directoryEntryIdentity,
-            // Inherit retryable from parent — downloadToLocal sets retryable: false
+            // Inherit retryable from parent - downloadToLocal sets retryable: false
             // because "local" targetConnectionId can't be resolved by retryTransfer
             retryable: task.retryable,
             // New/restarted child streams arm at bridge lifecycleEpoch 0. Never
@@ -773,7 +978,7 @@ export function useSftpDirectoryTransferOps({
                   ? {
                       ...t,
                       status: "failed" as TransferStatus,
-                      error: "SFTP session lost — reconnect and resume remaining files",
+                      error: "SFTP session lost - reconnect and resume remaining files",
                       speed: 0,
                       endTime: Date.now(),
                     }

application/state/sftp/transferPoolIdleTtl.test.ts

@@ -1,25 +0,0 @@
-import assert from "node:assert/strict";
-import test from "node:test";
-
-import {
-  DEFAULT_SFTP_TRANSFER_POOL_IDLE_TTL_MS,
-  isTransferPoolIdleReclaimDisabled,
-  resolveSftpTransferPoolIdleTtlMs,
-} from "../../../infrastructure/config/sftpTransferPool.ts";
-
-test("default pool idle TTL is five minutes", () => {
-  assert.equal(DEFAULT_SFTP_TRANSFER_POOL_IDLE_TTL_MS, 5 * 60_000);
-  assert.equal(resolveSftpTransferPoolIdleTtlMs(() => null), DEFAULT_SFTP_TRANSFER_POOL_IDLE_TTL_MS);
-});
-
-test("accepts preset values including never-reclaim zero", () => {
-  assert.equal(resolveSftpTransferPoolIdleTtlMs(() => 60_000), 60_000);
-  assert.equal(resolveSftpTransferPoolIdleTtlMs(() => 0), 0);
-  assert.equal(resolveSftpTransferPoolIdleTtlMs(() => 123), DEFAULT_SFTP_TRANSFER_POOL_IDLE_TTL_MS);
-});
-
-test("transfer pool idle reclaim helper is deprecated and always reclaim-enabled", () => {
-  // Channels close when idle; SSH park is separate. The helper always returns false.
-  assert.equal(isTransferPoolIdleReclaimDisabled(0), false);
-  assert.equal(isTransferPoolIdleReclaimDisabled(300_000), false);
-});

application/state/sftp/uploadTaskCallbacks.test.ts

@@ -59,3 +59,96 @@ test("upload task callbacks write through the transfer store without page callba
   assert.equal(patches[1].updates.transferredBytes, 100);
   assert.deepEqual(dismissed, []);
 });
+
+test("progress promotes pending scanning folder rows into transferring", () => {
+  const patches: Array<{ taskId: string; updates: Partial<TransferTask> }> = [];
+  const liveTask: TransferTask = {
+    id: "folder-1",
+    fileName: "docs",
+    sourcePath: "local",
+    targetPath: "/remote/docs",
+    sourceConnectionId: "external",
+    targetConnectionId: "connection-1",
+    direction: "upload",
+    status: "pending",
+    totalBytes: 0,
+    transferredBytes: 0,
+    speed: 0,
+    startTime: 1,
+    isDirectory: true,
+    progressMode: "files",
+    phase: "scanning",
+  };
+  const store = {
+    upsertTasks: () => {},
+    patchTask: (taskId: string, updates: Partial<TransferTask>) => patches.push({ taskId, updates }),
+    dismiss: () => {},
+    getTask: (taskId: string) => (taskId === "folder-1" ? liveTask : undefined),
+  };
+  const callbacks = createUploadTaskCallbacks({
+    ownerId: "owner-1",
+    connectionId: "connection-1",
+    targetPath: "/remote",
+    store,
+  });
+
+  callbacks.onTaskProgress?.("folder-1", {
+    transferred: 12,
+    total: 400,
+    speed: 0,
+    percent: 3,
+    phase: "transferring",
+  });
+
+  assert.equal(patches[0].taskId, "folder-1");
+  assert.equal(patches[0].updates.status, "transferring");
+  assert.equal(patches[0].updates.transferredBytes, 12);
+  assert.equal(patches[0].updates.totalBytes, 400);
+  assert.equal(patches[0].updates.phase, "transferring");
+});
+
+test("scanning callbacks expose live file counts in files progress mode", () => {
+  const upserts: TransferTask[][] = [];
+  const patches: Array<{ taskId: string; updates: Partial<TransferTask> }> = [];
+  const store = {
+    upsertTasks: (tasks: readonly TransferTask[]) => upserts.push([...tasks]),
+    patchTask: (taskId: string, updates: Partial<TransferTask>) => patches.push({ taskId, updates }),
+    dismiss: () => {},
+  };
+  const callbacks = createUploadTaskCallbacks({
+    ownerId: "owner-1",
+    connectionId: "connection-1",
+    targetPath: "/remote",
+    store,
+  });
+
+  callbacks.onScanningStart?.("scan-1", { label: "docs" });
+  callbacks.onScanningProgress?.("scan-1", {
+    fileCount: 1284,
+    directoryCount: 40,
+    entryCount: 1324,
+    label: "docs",
+  });
+
+  assert.equal(upserts[0][0].fileName, "docs");
+  assert.equal(upserts[0][0].phase, "scanning");
+  assert.equal(upserts[0][0].progressMode, "files");
+  assert.equal(upserts[0][0].status, "pending");
+  assert.deepEqual(patches[0], {
+    taskId: "scan-1",
+    updates: {
+      // Found files live in totalBytes; completed stays 0 during scan.
+      transferredBytes: 0,
+      totalBytes: 1284,
+      progressMode: "files",
+      phase: "scanning",
+      fileName: "docs",
+    },
+  });
+
+  // Display contract: 0 done · N found (not N done · N found).
+  const discovered = Math.max(patches[0].updates.totalBytes ?? 0, patches[0].updates.transferredBytes ?? 0);
+  const completed = patches[0].updates.transferredBytes ?? 0;
+  assert.equal(completed, 0);
+  assert.equal(discovered, 1284);
+});

application/state/sftp/uploadTaskCallbacks.ts

@@ -6,7 +6,7 @@ import { joinPath } from "./utils";
 type UploadTransferStore = Pick<
   typeof sftpTransferCenterStore,
   "upsertTasks" | "patchTask" | "dismiss"
->;
+> & Partial<Pick<typeof sftpTransferCenterStore, "getTask">>;
 
 interface UploadTaskCallbacksParams {
   ownerId: string;
@@ -27,11 +27,11 @@ export const createUploadTaskCallbacks = ({
   targetConnectionKey,
   store = sftpTransferCenterStore,
 }: UploadTaskCallbacksParams): UploadCallbacks => ({
-  onScanningStart: (taskId: string) => {
+  onScanningStart: (taskId: string, info?: { label?: string }) => {
     store.upsertTasks([{
       id: taskId,
       ownerId,
-      fileName: "Scanning files...",
+      fileName: info?.label?.trim() || "Scanning files...",
       sourcePath: "local",
       targetPath,
       sourceConnectionId: "external",
@@ -42,18 +42,30 @@ export const createUploadTaskCallbacks = ({
       targetConnectionKey,
       direction: "upload",
       status: "pending" as TransferStatus,
+      // Progressive discovery: totalBytes = found so far, completed stays 0
+      // until real transfers start (UI: "0 done · N found").
       totalBytes: 0,
       transferredBytes: 0,
       speed: 0,
       startTime: Date.now(),
       isDirectory: true,
-      progressMode: "bytes",
+      progressMode: "files",
       origin: "drag-drop",
       background: false,
       resumable: true,
       phase: "scanning",
     }]);
   },
+  onScanningProgress: (taskId: string, progress) => {
+    store.patchTask(taskId, {
+      // Found count is the growing total; nothing is completed during scan.
+      totalBytes: Math.max(0, progress.fileCount),
+      transferredBytes: 0,
+      progressMode: "files",
+      phase: "scanning",
+      ...(progress.label?.trim() ? { fileName: progress.label.trim() } : null),
+    });
+  },
   onScanningEnd: (taskId: string) => {
     store.dismiss(taskId);
   },
@@ -90,8 +102,36 @@ export const createUploadTaskCallbacks = ({
     const durableCheckpoint = Number.isFinite(Number(progress.checkpointBytes))
       ? Math.max(0, Math.trunc(Number(progress.checkpointBytes)))
       : progress.transferred;
+    // Progressive folder walks keep the scanning row as pending until real
+    // progress arrives. Promote pending/queued → transferring so the panel
+    // leaves "Waiting..." and matches the transfer-center live state.
+    const current = "getTask" in store && typeof store.getTask === "function"
+      ? store.getTask(taskId)
+      : undefined;
+    const shouldPromote =
+      !!current
+      && (current.status === "pending" || current.status === "queued")
+      && current.reconnectRequired !== true
+      && (
+        progress.phase === "scanning"
+        || progress.phase === "transferring"
+        || progress.transferred > 0
+        || progress.total > 0
+      );
     // Only patch fingerprint/checkpoint while paused — do not keep animating
     // high-water transferred after the user hit Pause.
+    const isPausedLike = current?.status === "paused" || current?.status === "pausing";
+    if (isPausedLike) {
+      store.patchTask(taskId, {
+        checkpointBytes: durableCheckpoint,
+        resumable: progress.resumable,
+        pauseUnavailableReason: progress.pauseUnavailableReason,
+        ...("sourceFingerprint" in progress && progress.sourceFingerprint
+          ? { sourceFingerprint: progress.sourceFingerprint as string }
+          : null),
+      });
+      return;
+    }
     store.patchTask(taskId, {
       transferredBytes: progress.transferred,
       totalBytes: progress.total,
@@ -101,6 +141,7 @@ export const createUploadTaskCallbacks = ({
       phase: progress.phase,
       resumable: progress.resumable,
       pauseUnavailableReason: progress.pauseUnavailableReason,
+      ...(shouldPromote ? { status: "transferring" as TransferStatus } : null),
       // Durable pause identity may arrive on a forced progress event while
       // status is already paused — keep it for restart/resume safety.
       ...("sourceFingerprint" in progress && progress.sourceFingerprint
@@ -121,6 +162,7 @@ export const createUploadTaskCallbacks = ({
       endTime: Date.now(),
       transferredBytes: totalBytes,
       speed: 0,
+      phase: undefined,
     });
   },
   onTaskFailed: (taskId: string, error: string) => {
@@ -129,6 +171,7 @@ export const createUploadTaskCallbacks = ({
       endTime: Date.now(),
       error,
       speed: 0,
+      phase: undefined,
     });
   },
   onTaskCancelled: (taskId: string) => {
@@ -136,6 +179,7 @@ export const createUploadTaskCallbacks = ({
       status: "cancelled" as TransferStatus,
       endTime: Date.now(),
       speed: 0,
+      phase: undefined,
     });
   },
 });

application/state/sftp/useSftpConnections.ts

@@ -2,6 +2,7 @@ import React, { useCallback, useEffect, useRef, useState } from "react";
 import type { MutableRefObject } from "react";
 import { netcattyBridge } from "../../../infrastructure/services/netcattyBridge";
 import type { Host, Identity, KnownHost, SftpConnection, SftpFileEntry, SftpFilenameEncoding, SSHKey } from "../../../domain/models";
+import { createKnownHostFromHostKeyInfo } from "../../../domain/knownHosts";
 import type { SftpHostKeyInfo, SftpHostKeyVerificationState, SftpPane } from "./types";
 import { useSftpDirectoryListing } from "./useSftpDirectoryListing";
 import { useSftpHostCredentials } from "./useSftpHostCredentials";
@@ -206,15 +207,7 @@ const createKnownHostFromSftpHostKeyInfo = (
   hostKeyInfo: SftpHostKeyInfo,
   now = Date.now(),
   idSuffix = Math.random().toString(36).slice(2, 11),
-): KnownHost => ({
-  id: hostKeyInfo.knownHostId || `kh-${now}-${idSuffix}`,
-  hostname: hostKeyInfo.hostname,
-  port: hostKeyInfo.port || 22,
-  keyType: hostKeyInfo.keyType,
-  publicKey: hostKeyInfo.publicKey || `SHA256:${hostKeyInfo.fingerprint}`,
-  fingerprint: hostKeyInfo.fingerprint,
-  discoveredAt: now,
-});
+): KnownHost => createKnownHostFromHostKeyInfo(hostKeyInfo, { now, idSuffix });
 
 export const useSftpConnections = ({
   hosts,

application/state/sftp/useSftpExternalOperations.ts

@@ -15,11 +15,63 @@ import {
   UploadResult,
   startUploadScanningTask,
 } from "../../../lib/uploadService";
-import { extractDropEntries, type DropEntry } from "../../../lib/sftpFileUtils";
+import { uploadLocalFoldersProgressively } from "../../../lib/progressiveFolderUpload";
+import {
+  captureDropPayload,
+  formatDropScanLabel,
+  isDropScanCancelledError,
+  localTreeToDropEntries,
+  materializeDropEntries,
+  type DropEntry,
+  type LocalTreeListEntry,
+} from "../../../lib/sftpFileUtils";
+
+function isUploadScanCancelled(controller: UploadController, error?: unknown): boolean {
+  return controller.isCancelled() || isDropScanCancelledError(error);
+}
 
 // Re-export UploadResult for external usage
 export type { UploadResult };
 
+type LocalTreeScanOptions = {
+  onProgress?: (progress: { fileCount: number; directoryCount: number; entryCount: number }) => void;
+  onEntries?: (entries: LocalTreeListEntry[]) => void;
+  abortSignal?: AbortSignal;
+};
+
+function createDropScanCancelledError(): Error {
+  const error = new Error("Drop scan cancelled");
+  (error as Error & { code?: string }).code = "ERR_DROP_SCAN_CANCELLED";
+  return error;
+}
+
+async function listLocalTreeWithAbort(
+  bridge: NetcattyBridge,
+  localPath: string,
+  options: LocalTreeScanOptions = {},
+): Promise<LocalTreeListEntry[]> {
+  const scanId = `drop-scan-${crypto.randomUUID()}`;
+  const abortSignal = options.abortSignal;
+  const requestCancel = () => {
+    void bridge.cancelLocalTreeScan?.(scanId);
+  };
+  if (abortSignal?.aborted) {
+    throw createDropScanCancelledError();
+  }
+  abortSignal?.addEventListener("abort", requestCancel, { once: true });
+  const { abortSignal: _abortSignal, ...bridgeOptions } = options;
+  try {
+    return await bridge.listLocalTree!(localPath, { ...bridgeOptions, scanId });
+  } catch (error) {
+    if (abortSignal?.aborted || isDropScanCancelledError(error)) {
+      throw createDropScanCancelledError();
+    }
+    throw error;
+  } finally {
+    abortSignal?.removeEventListener("abort", requestCancel);
+  }
+}
+
 import type { UseSftpExternalOperationsParams, SftpExternalOperationsResult } from "./useSftpExternalOperations.types";
 import { getSftpTransferResourceKeys, globalSftpTransferScheduler } from "./globalTransferScheduler";
 import { localStorageAdapter } from "../../../infrastructure/persistence/localStorageAdapter";
@@ -48,6 +100,10 @@ import {
   registerExternalUploadController,
   unregisterExternalUploadController,
 } from "./externalUploadRuntime";
+import {
+  isTransferPauseLatched,
+  waitWhileTransferOrRootPaused,
+} from "./transferPauseLatch";
 
 type UploadConflictResolver = {
   resolve: (action: FileConflictAction) => void;
@@ -151,9 +207,12 @@ export const useSftpExternalOperations = (
     callbacks: UploadCallbacks,
   ): UploadCallbacks => ({
     ...callbacks,
-    onScanningStart: (taskId) => {
+    onScanningStart: (taskId, info) => {
       registerUploadController(taskId, controller);
-      callbacks.onScanningStart?.(taskId);
+      callbacks.onScanningStart?.(taskId, info);
+    },
+    onScanningProgress: (taskId, progress) => {
+      callbacks.onScanningProgress?.(taskId, progress);
     },
     onTaskCreated: (task) => {
       registerUploadController(task.id, controller);
@@ -764,9 +823,12 @@ export const useSftpExternalOperations = (
             conflictDefaults.set(conflictType, action);
           },
         });
+        controller.addCancelListener(() => {
+          cancelPendingUploadConflicts(controller);
+        });
       });
     };
-  }, []);
+  }, [cancelPendingUploadConflicts]);
 
   // Create upload bridge that wraps netcattyBridge.
   // Pass connect-time Host so pooled stream uploads open the pinned endpoint
@@ -888,52 +950,271 @@ export const useSftpExternalOperations = (
 
   const uploadExternalFiles = useCallback(
     async (side: "left" | "right", dataTransfer: DataTransfer, targetPath?: string): Promise<UploadResult[]> => {
-      // DataTransfer is only valid during the drop event. Capture entries BEFORE
+      // DataTransfer is only valid during the drop event. Capture roots BEFORE
       // any await (session reconnect can take seconds while a transfer is busy).
-      // Otherwise extractDropEntries returns [] and the UI toasts "Uploaded files: 0".
-      let capturedEntries: DropEntry[];
-      try {
-        capturedEntries = await extractDropEntries(dataTransfer);
-      } catch (error) {
-        logger.error("[SFTP] Failed to read dropped files:", error);
-        throw error;
-      }
-      if (capturedEntries.length === 0) {
+      // Native tree expansion (listLocalTree) happens after the scanning UI is up.
+      const dropPayload = captureDropPayload(dataTransfer);
+      if (dropPayload.roots.length === 0 && dropPayload.filesFallback.length === 0) {
         return [];
       }
 
+      const pane = getActivePane(side);
+      if (!pane?.connection) {
+        throw new Error("No active connection");
+      }
+      const bridge = netcattyBridge.get();
+      if (!bridge) {
+        throw new Error("Bridge not available");
+      }
+
+      const uploadTargetPath = targetPath || pane.connection.currentPath;
+      const controller = new UploadController();
+      const callbacks = bindUploadControllerCallbacks(
+        controller,
+        createUploadCallbacks(
+          pane.connection.id,
+          uploadTargetPath,
+          pane.connection.isLocal ? undefined : pane.connection.hostId,
+          pane.connection.isLocal ? undefined : connectionCacheKeyMapRef.current.get(pane.connection.id),
+          pane.connection.isLocal ? undefined : pane.connection.hostLabel,
+        ),
+      );
+
+      const pathBackedFolderRoots = dropPayload.roots
+        .filter((root) => root.isDirectory && !!root.localPath)
+        .map((root) => ({ name: root.name, localPath: root.localPath! }));
+      // Progressive only when *every* root is a path-backed folder. Mixed drops
+      // (folder + files, path-less dirs) must fall through to materialize so
+      // sibling items are not silently dropped.
+      const canProgressiveUpload = pathBackedFolderRoots.length > 0
+        && pathBackedFolderRoots.length === dropPayload.roots.length
+        && !!bridge.listLocalTree
+        && !useCompressedUpload;
+      const needsDeepScan = dropPayload.roots.some((root) => root.isDirectory);
+      const scanLabel = formatDropScanLabel(dropPayload.roots);
+      // Instant feedback: scanning / parent row appears before work begins.
+      const scanningTask = needsDeepScan
+        ? startUploadScanningTask(callbacks, crypto.randomUUID(), { label: scanLabel })
+        : null;
+      if (scanningTask && typeof window !== "undefined") {
+        window.dispatchEvent(new CustomEvent("netcatty:open-sftp-transfer-center"));
+      }
+
+      const scanAbort = new AbortController();
+      const detachScanCancel = controller.addCancelListener(() => {
+        scanAbort.abort();
+        if (scanningTask?.isOpen()) scanningTask.cancel();
+      });
+
+      // Path-backed folders (no compressed upload): edge-scan + edge-transfer.
+      // Open the SFTP session first, then stream discovery batches into upload
+      // workers so the first files start while the rest of the tree is still walking.
+      if (canProgressiveUpload) {
+        const runProgressive = async (forceReconnect = false): Promise<UploadResult[]> => {
+          const { sftpId, release } = await resolveRemoteSftpId(side, { forceReconnect });
+          const livePane = getActivePane(side) ?? pane;
+          if (!livePane.connection) {
+            release();
+            throw new Error("No active connection");
+          }
+          const uploadPaneId = livePane.id;
+          const liveTargetPath = targetPath || livePane.connection.currentPath;
+          const connectHost = resolveUploadConnectHost(uploadPaneId, livePane.connection.isLocal);
+          const uploadBridge = createUploadBridge(connectHost);
+          const liveCallbacks = livePane.connection.id === pane.connection.id
+            && liveTargetPath === uploadTargetPath
+            ? callbacks
+            : bindUploadControllerCallbacks(
+              controller,
+              createUploadCallbacks(
+                livePane.connection.id,
+                liveTargetPath,
+                livePane.connection.isLocal ? undefined : livePane.connection.hostId,
+                livePane.connection.isLocal ? undefined : connectionCacheKeyMapRef.current.get(livePane.connection.id),
+                livePane.connection.isLocal ? undefined : livePane.connection.hostLabel,
+              ),
+            );
+
+          const parentTaskIds = new Map<string, string>();
+          if (scanningTask && pathBackedFolderRoots.length === 1) {
+            parentTaskIds.set(pathBackedFolderRoots[0].name, scanningTask.taskId);
+            // Keep the scanning row as the folder parent (do not dismiss it).
+            scanningTask.complete = () => {
+              /* no-op: progressive path settles via onTaskCompleted/Cancelled */
+            };
+          } else if (scanningTask?.isOpen()) {
+            scanningTask.complete();
+          }
+
+          try {
+            if (controller.isCancelled()) {
+              scanningTask?.cancel();
+              return [{ fileName: "", success: false, cancelled: true }];
+            }
+            const results = await uploadLocalFoldersProgressively(
+              pathBackedFolderRoots,
+              {
+                targetPath: liveTargetPath,
+                sftpId,
+                targetHostId: livePane.connection.isLocal ? undefined : livePane.connection.hostId,
+                isLocal: livePane.connection.isLocal,
+                bridge: uploadBridge,
+                joinPath,
+                callbacks: liveCallbacks,
+                parentTaskIds,
+                abortSignal: scanAbort.signal,
+                // Soft-pause must freeze discovery enqueue + child UI rows, not
+                // only the open streams (otherwise Pause still floods the queue).
+                waitWhilePaused: (parentTaskId) => waitWhileTransferOrRootPaused(parentTaskId),
+                isPaused: (parentTaskId) => isTransferPauseLatched(parentTaskId),
+                resolveConflict: createUploadConflictResolver(controller),
+                listLocalTree: (localPath, treeOptions) => listLocalTreeWithAbort(bridge, localPath, {
+                  ...treeOptions,
+                  abortSignal: scanAbort.signal,
+                }),
+              },
+              controller,
+            );
+            if (clearDirCacheEntry && targetPath) {
+              clearDirCacheEntry(livePane.connection.id, liveTargetPath);
+            }
+            if (liveTargetPath === livePane.connection.currentPath) {
+              await refresh(side, { tabId: uploadPaneId });
+            }
+            return results;
+          } finally {
+            release();
+          }
+        };
+
+        try {
+          return await runProgressive(false);
+        } catch (error) {
+          if (isSessionError(error) && ensureRemoteSftpId) {
+            logger.warn("[SFTP] Progressive upload session lost; reconnecting once", error);
+            try {
+              return await runProgressive(true);
+            } catch (retryError) {
+              if (isUploadScanCancelled(controller, retryError)) {
+                scanningTask?.cancel();
+                return [{ fileName: "", success: false, cancelled: true }];
+              }
+              if (scanningTask?.isOpen()) scanningTask.fail(retryError);
+              throw retryError;
+            }
+          }
+          if (isUploadScanCancelled(controller, error)) {
+            scanningTask?.cancel();
+            return [{ fileName: "", success: false, cancelled: true }];
+          }
+          if (scanningTask?.isOpen()) scanningTask.fail(error);
+          logger.error("[SFTP] Progressive folder upload failed:", error);
+          throw error;
+        } finally {
+          detachScanCancel();
+          unregisterUploadController(controller);
+        }
+      }
+
+      let capturedEntries: DropEntry[] = [];
+      try {
+        const scanT0 = performance.now();
+        capturedEntries = await materializeDropEntries(dropPayload, {
+          abortSignal: scanAbort.signal,
+          isCancelled: () => controller.isCancelled(),
+          listLocalTree: bridge.listLocalTree
+            ? (localPath, treeOptions) => listLocalTreeWithAbort(bridge, localPath, {
+              ...treeOptions,
+              abortSignal: scanAbort.signal,
+            })
+            : undefined,
+          onProgress: scanningTask
+            ? (progress) => {
+              callbacks.onScanningProgress?.(scanningTask.taskId, {
+                ...progress,
+                label: progress.label || scanLabel,
+              });
+            }
+            : undefined,
+        });
+        logger.debug(
+          `[SFTP:perf] materializeDropEntries — ${capturedEntries.length} entries — ${(performance.now() - scanT0).toFixed(0)}ms`,
+        );
+      } catch (error) {
+        if (scanningTask?.isOpen()) {
+          if (isUploadScanCancelled(controller, error)) {
+            scanningTask.cancel();
+          } else {
+            scanningTask.fail(error);
+          }
+        }
+        detachScanCancel();
+        unregisterUploadController(controller);
+        if (isUploadScanCancelled(controller, error)) {
+          return [{ fileName: "", success: false, cancelled: true }];
+        }
+        logger.error("[SFTP] Failed to read dropped files:", error);
+        throw error;
+      }
+
+      if (controller.isCancelled()) {
+        scanningTask?.cancel();
+        detachScanCancel();
+        unregisterUploadController(controller);
+        return [{ fileName: "", success: false, cancelled: true }];
+      }
+      if (capturedEntries.length === 0) {
+        scanningTask?.complete();
+        detachScanCancel();
+        unregisterUploadController(controller);
+        return [];
+      }
+
+      // Keep scanning visible through session open so the UI never goes blank
+      // between "N files found" and the real transfer rows.
       const run = async (forceReconnect = false): Promise<UploadResult[]> => {
-        const pane = getActivePane(side);
-        if (!pane?.connection) {
+        const { sftpId, release } = await resolveRemoteSftpId(side, { forceReconnect });
+        const livePane = getActivePane(side) ?? pane;
+        if (!livePane.connection) {
+          release();
           throw new Error("No active connection");
         }
 
-        const bridge = netcattyBridge.get();
-        if (!bridge) {
-          throw new Error("Bridge not available");
-        }
-
-        const { sftpId, release } = await resolveRemoteSftpId(side, { forceReconnect });
-        const livePane = getActivePane(side) ?? pane;
-        if (!livePane.connection) throw new Error("No active connection");
-
         const uploadPaneId = livePane.id;
-        const uploadTargetPath = targetPath || livePane.connection.currentPath;
-        const controller = new UploadController();
-        const callbacks = bindUploadControllerCallbacks(
-          controller,
-          createUploadCallbacks(
-            livePane.connection.id,
-            uploadTargetPath,
-            livePane.connection.isLocal ? undefined : livePane.connection.hostId,
-            livePane.connection.isLocal ? undefined : connectionCacheKeyMapRef.current.get(livePane.connection.id),
-            livePane.connection.isLocal ? undefined : livePane.connection.hostLabel,
-          ),
-        );
+        const liveTargetPath = targetPath || livePane.connection.currentPath;
         const connectHost = resolveUploadConnectHost(uploadPaneId, livePane.connection.isLocal);
         const uploadBridge = createUploadBridge(connectHost);
 
+        // Retarget callbacks if the pane path/id changed after reconnect.
+        const liveCallbacks = livePane.connection.id === pane.connection.id
+          && liveTargetPath === uploadTargetPath
+          ? callbacks
+          : bindUploadControllerCallbacks(
+            controller,
+            createUploadCallbacks(
+              livePane.connection.id,
+              liveTargetPath,
+              livePane.connection.isLocal ? undefined : livePane.connection.hostId,
+              livePane.connection.isLocal ? undefined : connectionCacheKeyMapRef.current.get(livePane.connection.id),
+              livePane.connection.isLocal ? undefined : livePane.connection.hostLabel,
+            ),
+          );
+        const transferCallbacks = scanningTask
+          ? {
+              ...liveCallbacks,
+              onTaskCreated: (task: Parameters<NonNullable<UploadCallbacks["onTaskCreated"]>>[0]) => {
+                scanningTask.complete();
+                liveCallbacks.onTaskCreated?.(task);
+              },
+            }
+          : liveCallbacks;
+
+        let transferSucceeded = false;
         try {
+          if (controller.isCancelled()) {
+            scanningTask?.cancel();
+            return [{ fileName: "", success: false, cancelled: true }];
+          }
           const hasDirectory = capturedEntries.some((entry) => (
             entry.isDirectory || entry.relativePath.replace(/\\/g, "/").includes("/")
           ));
@@ -951,13 +1232,13 @@ export const useSftpExternalOperations = (
             run: async (uploadSftpId) => uploadEntriesDirect(
               capturedEntries,
               {
-                targetPath: uploadTargetPath,
+                targetPath: liveTargetPath,
                 sftpId: uploadSftpId,
                 targetHostId: livePane.connection!.isLocal ? undefined : livePane.connection!.hostId,
                 isLocal: livePane.connection!.isLocal,
                 bridge: uploadBridge,
                 joinPath,
-                callbacks,
+                callbacks: transferCallbacks,
                 useCompressedUpload,
                 resolveConflict: createUploadConflictResolver(controller),
               },
@@ -966,15 +1247,19 @@ export const useSftpExternalOperations = (
           });
 
           if (clearDirCacheEntry && targetPath) {
-            clearDirCacheEntry(livePane.connection.id, uploadTargetPath);
+            clearDirCacheEntry(livePane.connection.id, liveTargetPath);
           }
-          if (uploadTargetPath === livePane.connection.currentPath) {
+          if (liveTargetPath === livePane.connection.currentPath) {
             await refresh(side, { tabId: uploadPaneId });
           }
+          transferSucceeded = true;
           return results;
         } finally {
+          if (scanningTask?.isOpen()) {
+            if (controller.isCancelled()) scanningTask.cancel();
+            else if (transferSucceeded) scanningTask.complete();
+          }
           release();
-          unregisterUploadController(controller);
         }
       };
 
@@ -983,10 +1268,26 @@ export const useSftpExternalOperations = (
       } catch (error) {
         if (isSessionError(error) && ensureRemoteSftpId) {
           logger.warn("[SFTP] Upload session lost; reconnecting and retrying once", error);
-          return await run(true);
+          try {
+            return await run(true);
+          } catch (retryError) {
+            if (isUploadScanCancelled(controller, retryError)) {
+              scanningTask?.cancel();
+            } else if (scanningTask?.isOpen()) {
+              scanningTask.fail(retryError);
+            }
+            throw retryError;
+          }
+        }
+        if (scanningTask?.isOpen()) {
+          if (controller.isCancelled()) scanningTask.cancel();
+          else scanningTask.fail(error);
         }
         logger.error("[SFTP] Upload failed:", error);
         throw error;
+      } finally {
+        detachScanCancel();
+        unregisterUploadController(controller);
       }
     },
     [
@@ -1146,105 +1447,125 @@ export const useSftpExternalOperations = (
         connectionCacheKeyMapRef.current,
       );
 
+      const initialUploadTargetPath = targetPath || originatingPane.connection.currentPath;
+      const controller = new UploadController();
+      const callbacks = bindUploadControllerCallbacks(
+        controller,
+        createUploadCallbacks(
+          originatingPane.connection.id,
+          initialUploadTargetPath,
+          originatingPane.connection.isLocal ? undefined : originatingPane.connection.hostId,
+          originatingPane.connection.isLocal
+            ? undefined
+            : connectionCacheKeyMapRef.current.get(originatingPane.connection.id),
+          originatingPane.connection.isLocal ? undefined : originatingPane.connection.hostLabel,
+        ),
+      );
+      const folderName = folderPath.replace(/\\/g, "/").split("/").filter(Boolean).pop()
+        || folderPath;
+      const scanningTask = startUploadScanningTask(callbacks, crypto.randomUUID(), {
+        label: folderName,
+      });
+      if (typeof window !== "undefined") {
+        window.dispatchEvent(new CustomEvent("netcatty:open-sftp-transfer-center"));
+      }
+      const scanAbort = new AbortController();
+      const detachScanCancel = controller.addCancelListener(() => {
+        scanAbort.abort();
+        if (scanningTask.isOpen()) scanningTask.cancel();
+      });
+      let capturedEntries: DropEntry[] | null = null;
+
       const run = async (forceReconnect = false): Promise<UploadResult[]> => {
-        const pane = resolveUploadTargetPane({
-          side,
-          tabId: originatingTabId,
-          getActivePane,
-          getPaneByTabId,
-          getPaneByConnectionId,
-        });
-        assertUploadEndpointUnchanged(
-          pane.connection,
-          originatingEndpoint,
-          connectionCacheKeyMapRef.current,
-        );
-        const bridge = netcattyBridge.get();
-        if (!bridge) throw new Error("Bridge not available");
-        if (!bridge.listLocalTree) throw new Error("Folder upload not supported");
-
-        const { sftpId, release } = await resolveRemoteSftpId(side, {
-          forceReconnect,
-          connectionId: pane.connection.id,
-          tabId: originatingTabId,
-        });
-        // Never re-resolve via getActivePane after awaits — focus may have moved.
-        const livePane = resolveUploadTargetPane({
-          side,
-          tabId: originatingTabId,
-          getActivePane,
-          getPaneByTabId,
-          getPaneByConnectionId,
-        });
-        assertUploadEndpointUnchanged(
-          livePane.connection,
-          originatingEndpoint,
-          connectionCacheKeyMapRef.current,
-        );
-
-        const uploadPaneId = livePane.id;
-        const uploadTargetPath = targetPath || livePane.connection.currentPath;
-        const controller = new UploadController();
-
-        const callbacks = bindUploadControllerCallbacks(
-          controller,
-          createUploadCallbacks(
-            livePane.connection.id,
-            uploadTargetPath,
-            livePane.connection.isLocal ? undefined : livePane.connection.hostId,
-            livePane.connection.isLocal ? undefined : connectionCacheKeyMapRef.current.get(livePane.connection.id),
-            livePane.connection.isLocal ? undefined : livePane.connection.hostLabel,
-          ),
-        );
-        // Pin connect-time Host before listLocalTree: a slow folder scan can
-        // outlive a same-hostId tab rebind, and resolveUploadConnectHost would
-        // otherwise open the pooled stream bridge on the newly selected endpoint.
-        const uploadConnectHost = resolveUploadConnectHost(
-          uploadPaneId,
-          livePane.connection.isLocal,
-        );
-        const uploadBridge = createUploadBridge(uploadConnectHost);
-
-        const scanningTask = startUploadScanningTask(callbacks);
-
+        if (controller.isCancelled()) {
+          scanningTask.cancel();
+          return [{ fileName: "", success: false, cancelled: true }];
+        }
+        let release = () => {};
         try {
-          const localEntries = await bridge.listLocalTree(folderPath);
+          const pane = resolveUploadTargetPane({
+            side,
+            tabId: originatingTabId,
+            getActivePane,
+            getPaneByTabId,
+            getPaneByConnectionId,
+          });
+          assertUploadEndpointUnchanged(
+            pane.connection,
+            originatingEndpoint,
+            connectionCacheKeyMapRef.current,
+          );
+          const bridge = netcattyBridge.get();
+          if (!bridge) throw new Error("Bridge not available");
+          if (!bridge.listLocalTree) throw new Error("Folder upload not supported");
+
+          const resolved = await resolveRemoteSftpId(side, {
+            forceReconnect,
+            connectionId: pane.connection.id,
+            tabId: originatingTabId,
+          });
+          const sftpId = resolved.sftpId;
+          release = resolved.release;
+          // Never re-resolve via getActivePane after awaits — focus may have moved.
+          const livePane = resolveUploadTargetPane({
+            side,
+            tabId: originatingTabId,
+            getActivePane,
+            getPaneByTabId,
+            getPaneByConnectionId,
+          });
+          assertUploadEndpointUnchanged(
+            livePane.connection,
+            originatingEndpoint,
+            connectionCacheKeyMapRef.current,
+          );
+
+          const uploadPaneId = livePane.id;
+          const uploadTargetPath = targetPath || livePane.connection.currentPath;
+          // Pin connect-time Host before listLocalTree: a slow folder scan can
+          // outlive a same-hostId tab rebind, and resolveUploadConnectHost would
+          // otherwise open the pooled stream bridge on the newly selected endpoint.
+          const uploadConnectHost = resolveUploadConnectHost(
+            uploadPaneId,
+            livePane.connection.isLocal,
+          );
+          const uploadBridge = createUploadBridge(uploadConnectHost);
+          const liveCallbacks = bindUploadControllerCallbacks(
+            controller,
+            createUploadCallbacks(
+              livePane.connection.id,
+              uploadTargetPath,
+              livePane.connection.isLocal ? undefined : livePane.connection.hostId,
+              livePane.connection.isLocal
+                ? undefined
+                : connectionCacheKeyMapRef.current.get(livePane.connection.id),
+              livePane.connection.isLocal ? undefined : livePane.connection.hostLabel,
+            ),
+          );
+          const transferCallbacks = {
+            ...liveCallbacks,
+            onTaskCreated: (task: Parameters<NonNullable<UploadCallbacks["onTaskCreated"]>>[0]) => {
+              scanningTask.complete();
+              liveCallbacks.onTaskCreated?.(task);
+            },
+          };
+
+          if (capturedEntries === null) {
+            const localEntries = await listLocalTreeWithAbort(bridge, folderPath, {
+              abortSignal: scanAbort.signal,
+              onProgress: (progress) => {
+                callbacks.onScanningProgress?.(scanningTask.taskId, {
+                  ...progress,
+                  label: folderName,
+                });
+              },
+            });
+            capturedEntries = localTreeToDropEntries(localEntries);
+          }
           if (controller.isCancelled()) {
             scanningTask.cancel();
             return [{ fileName: "", success: false, cancelled: true }];
           }
-          scanningTask.complete();
-
-          const entries: DropEntry[] = localEntries.map((entry) => {
-            if (entry.type === "directory") {
-              return {
-                file: null,
-                relativePath: entry.relativePath,
-                isDirectory: true,
-              };
-            }
-
-            const file = {
-              name: entry.relativePath.split("/").pop() || entry.relativePath,
-              size: entry.size,
-              lastModified: entry.lastModified,
-              type: "",
-              path: entry.localPath,
-              arrayBuffer: async () => {
-                const currentBridge = netcattyBridge.get();
-                if (!currentBridge?.readLocalFile) {
-                  throw new Error("Local file reading not supported");
-                }
-                return currentBridge.readLocalFile(entry.localPath);
-              },
-            } as File & { path?: string };
-
-            return {
-              file,
-              relativePath: entry.relativePath,
-              isDirectory: false,
-            };
-          });
 
           const results = await runWithCompressedUploadSession({
             enabled: useCompressedUpload,
@@ -1258,7 +1579,7 @@ export const useSftpExternalOperations = (
               : undefined,
             shouldDiscard: isSessionError,
             run: async (uploadSftpId) => uploadEntriesDirect(
-              entries,
+              capturedEntries,
               {
                 targetPath: uploadTargetPath,
                 sftpId: uploadSftpId,
@@ -1266,7 +1587,7 @@ export const useSftpExternalOperations = (
                 isLocal: livePane.connection!.isLocal,
                 bridge: uploadBridge,
                 joinPath,
-                callbacks,
+                callbacks: transferCallbacks,
                 useCompressedUpload,
                 resolveConflict: createUploadConflictResolver(controller),
               },
@@ -1282,18 +1603,8 @@ export const useSftpExternalOperations = (
             await refresh(refreshSide, { tabId: uploadPaneId });
           }
           return results;
-        } catch (error) {
-          if (controller.isCancelled()) {
-            scanningTask.cancel();
-            return [{ fileName: "", success: false, cancelled: true }];
-          }
-          if (scanningTask.isOpen()) {
-            scanningTask.fail(error);
-          }
-          throw error;
         } finally {
           release();
-          unregisterUploadController(controller);
         }
       };
 
@@ -1302,11 +1613,33 @@ export const useSftpExternalOperations = (
       } catch (error) {
         if (isSessionError(error) && ensureRemoteSftpId) {
           logger.warn("[SFTP] Folder upload session lost; reconnecting and retrying once", error);
-          return await run(true);
+          try {
+            return await run(true);
+          } catch (retryError) {
+            if (isUploadScanCancelled(controller, retryError)) {
+              scanningTask.cancel();
+              return [{ fileName: "", success: false, cancelled: true }];
+            }
+            if (scanningTask.isOpen()) scanningTask.fail(retryError);
+            throw retryError;
+          }
         }
+        if (isUploadScanCancelled(controller, error)) {
+          scanningTask.cancel();
+          return [{ fileName: "", success: false, cancelled: true }];
+        }
+        if (scanningTask.isOpen()) scanningTask.fail(error);
         logger.error("[SFTP] Folder picker upload failed:", error);
         throw error;
       }
+      finally {
+        detachScanCancel();
+        unregisterUploadController(controller);
+        if (scanningTask.isOpen()) {
+          if (controller.isCancelled()) scanningTask.cancel();
+          else scanningTask.complete();
+        }
+      }
     },
     [
       acquireTransferSession,

application/state/sftp/useSftpPaneSorting.architecture.test.ts

@@ -0,0 +1,10 @@
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import test from "node:test";
+
+const source = readFileSync(new URL("./useSftpPaneSorting.ts", import.meta.url), "utf8");
+
+test("useSftpPaneSorting imports column layout from application state", () => {
+  assert.doesNotMatch(source, /from ["'].*components\//);
+  assert.match(source, /from ["']\.\/columnLayout["']/);
+});

application/state/sftp/useSftpPaneSorting.ts

@@ -0,0 +1,168 @@
+import React, { useCallback, useEffect, useRef, useState } from "react";
+import {
+  DEFAULT_SFTP_COLUMN_VISIBILITY,
+  normalizeSftpColumnVisibility,
+  type ColumnWidths,
+  type SftpColumnVisibility,
+  type SortField,
+  type SortOrder,
+} from "./columnLayout";
+import { STORAGE_KEY_SFTP_VISIBLE_COLUMNS } from "../../../infrastructure/config/storageKeys";
+import {
+  LOCAL_STORAGE_ADAPTER_CHANGED_EVENT,
+  localStorageAdapter,
+} from "../../../infrastructure/persistence/localStorageAdapter";
+import { useSftpDirectoriesFirst } from "./useSftpDirectoriesFirst";
+
+export interface UseSftpPaneSortingResult {
+  sortField: SortField;
+  sortOrder: SortOrder;
+  directoriesFirst: boolean;
+  columnWidths: ColumnWidths;
+  visibleColumns: SftpColumnVisibility;
+  handleSort: (field: SortField) => void;
+  handleResizeStart: (field: keyof ColumnWidths, e: React.MouseEvent) => void;
+  toggleColumnVisibility: (field: keyof ColumnWidths) => void;
+  toggleDirectoriesFirst: () => void;
+}
+
+export const useSftpPaneSorting = (): UseSftpPaneSortingResult => {
+  const [sortField, setSortField] = useState<SortField>("name");
+  const [sortOrder, setSortOrder] = useState<SortOrder>("asc");
+  const { directoriesFirst, toggleDirectoriesFirst } = useSftpDirectoriesFirst();
+  const [columnWidths, setColumnWidths] = useState<ColumnWidths>({
+    name: 56,
+    modified: 28,
+    size: 7,
+    type: 9,
+  });
+  const [visibleColumns, setVisibleColumns] = useState<SftpColumnVisibility>(() =>
+    normalizeSftpColumnVisibility(
+      localStorageAdapter.read<Partial<SftpColumnVisibility>>(STORAGE_KEY_SFTP_VISIBLE_COLUMNS),
+    ),
+  );
+
+  useEffect(() => {
+    const syncVisibleColumns = (event: Event) => {
+      if (event instanceof StorageEvent && event.key !== STORAGE_KEY_SFTP_VISIBLE_COLUMNS) return;
+      if (event instanceof CustomEvent && event.detail?.key !== STORAGE_KEY_SFTP_VISIBLE_COLUMNS) return;
+      const next = normalizeSftpColumnVisibility(
+        localStorageAdapter.read<Partial<SftpColumnVisibility>>(STORAGE_KEY_SFTP_VISIBLE_COLUMNS),
+      );
+      setVisibleColumns(next);
+    };
+
+    window.addEventListener("storage", syncVisibleColumns);
+    window.addEventListener(LOCAL_STORAGE_ADAPTER_CHANGED_EVENT, syncVisibleColumns);
+    return () => {
+      window.removeEventListener("storage", syncVisibleColumns);
+      window.removeEventListener(LOCAL_STORAGE_ADAPTER_CHANGED_EVENT, syncVisibleColumns);
+    };
+  }, []);
+
+  useEffect(() => {
+    if (visibleColumns[sortField]) return;
+    setSortField("name");
+    setSortOrder("asc");
+  }, [sortField, visibleColumns]);
+
+  const toggleColumnVisibility = useCallback((field: keyof ColumnWidths) => {
+    if (field === "name") return;
+    setVisibleColumns((current) => {
+      const next = {
+        ...DEFAULT_SFTP_COLUMN_VISIBILITY,
+        ...current,
+        name: true,
+        [field]: !current[field],
+      };
+      localStorageAdapter.write(STORAGE_KEY_SFTP_VISIBLE_COLUMNS, next);
+      return next;
+    });
+  }, []);
+
+  const resizingRef = useRef<{
+    field: keyof ColumnWidths;
+    startX: number;
+    startWidth: number;
+  } | null>(null);
+
+  const handleSort = useCallback((field: SortField) => {
+    if (sortField === field) {
+      setSortOrder((prev) => (prev === "asc" ? "desc" : "asc"));
+    } else {
+      setSortField(field);
+      setSortOrder("asc");
+    }
+  }, [sortField]);
+
+  const rafIdRef = useRef<number | null>(null);
+  const lastClientXRef = useRef(0);
+
+  const applyColumnWidth = useCallback(() => {
+    if (!resizingRef.current) return;
+    const { field, startX, startWidth } = resizingRef.current;
+    const diff = lastClientXRef.current - startX;
+    const limits: Record<keyof ColumnWidths, { min: number; max: number }> = {
+      name: { min: 36, max: 78 },
+      modified: { min: 18, max: 42 },
+      size: { min: 5, max: 16 },
+      type: { min: 6, max: 18 },
+    };
+    const { min, max } = limits[field];
+    const newWidth = Math.max(
+      min,
+      Math.min(max, startWidth + diff / 8),
+    );
+    setColumnWidths((prev) => ({
+      ...prev,
+      [field]: newWidth,
+    }));
+  }, []);
+
+  const handleResizeMove = useCallback((e: MouseEvent) => {
+    if (!resizingRef.current) return;
+    lastClientXRef.current = e.clientX;
+    if (rafIdRef.current !== null) return;
+    rafIdRef.current = requestAnimationFrame(() => {
+      rafIdRef.current = null;
+      applyColumnWidth();
+    });
+  }, [applyColumnWidth]);
+
+  const handleResizeEnd = useCallback(() => {
+    if (rafIdRef.current !== null) cancelAnimationFrame(rafIdRef.current);
+    applyColumnWidth();
+    rafIdRef.current = null;
+    resizingRef.current = null;
+    document.removeEventListener("mousemove", handleResizeMove);
+    document.removeEventListener("mouseup", handleResizeEnd);
+  }, [applyColumnWidth, handleResizeMove]);
+
+  const handleResizeStart = (
+    field: keyof ColumnWidths,
+    e: React.MouseEvent,
+  ) => {
+    e.preventDefault();
+    e.stopPropagation();
+    lastClientXRef.current = e.clientX;
+    resizingRef.current = {
+      field,
+      startX: e.clientX,
+      startWidth: columnWidths[field],
+    };
+    document.addEventListener("mousemove", handleResizeMove);
+    document.addEventListener("mouseup", handleResizeEnd);
+  };
+
+  return {
+    sortField,
+    sortOrder,
+    directoriesFirst,
+    columnWidths,
+    visibleColumns,
+    handleSort,
+    handleResizeStart,
+    toggleColumnVisibility,
+    toggleDirectoriesFirst,
+  };
+};

application/state/sftp/useSftpTransferLifecycle.ts

@@ -2,25 +2,6 @@ import { useEffect, useLayoutEffect, useRef } from "react";
 
 import { sftpTransferCenterStore } from "../sftpTransferCenterStore";
 
-export function useWarmSftpTransferPool(params: {
-  hostIds: readonly string[];
-  activeHostId?: string;
-  warmTransferPoolForHost?: (hostId: string) => void | Promise<void>;
-}) {
-  const warmRef = useRef(params.warmTransferPoolForHost);
-  warmRef.current = params.warmTransferPoolForHost;
-  const hostIdsKey = [...new Set([
-    ...params.hostIds,
-    ...(params.activeHostId ? [params.activeHostId] : []),
-  ])].sort().join("\u0000");
-
-  useEffect(() => {
-    for (const hostId of hostIdsKey.split("\u0000").filter(Boolean)) {
-      void warmRef.current?.(hostId);
-    }
-  }, [hostIdsKey]);
-}
-
 export function useReportSftpTransferOwnerActivity(params: {
   ownerId: string;
   activeTransfersCount: number;

application/state/sftp/useSftpTransfers.ts

@@ -60,6 +60,10 @@ import {
 } from "./transferConflictLifecycle";
 import { getParentPath, joinPath } from "./utils";
 import { promoteDirectoryReplaceStage as promoteDirectoryReplacePaths } from "./directoryReplacePromotion";
+import {
+  isExternalDragDropFileUpload,
+  retryExternalDragDropFileUpload,
+} from "./externalDragDropRetry";
 
 /** Keep the MutableRefObject mirror in sync with the process-global latch set. */
 function syncPausedTasksRef(ref: { current: Set<string> }, taskId: string, latched: boolean) {
@@ -1294,8 +1298,62 @@ export const useSftpTransfers = ({
 
   const retryTransfer = useCallback(
     async (transferId: string) => {
-      const task = transfersRef.current.find((t) => t.id === transferId);
+      // Prefer the live owner list; fall back to the center store (drag-drop
+      // children are upserted there and mirrored via subscribe).
+      const task = transfersRef.current.find((t) => t.id === transferId)
+        ?? sftpTransferCenterStore.getTask(transferId);
       if (!task || task.retryable === false) return;
+
+      // Progressive / external drag-drop children never have dual-pane endpoints
+      // (sourceConnectionId is "external"). Re-run startStreamTransfer in place.
+      if (isExternalDragDropFileUpload(task)) {
+        if (inFlightTransferIdsRef.current.has(transferId)) return;
+        inFlightTransferIdsRef.current.add(transferId);
+        clearTransferCancelled(transferId);
+        cancelledTasksRef.current.delete(transferId);
+        try {
+          const result = await retryExternalDragDropFileUpload(task, {
+            getBrowseSftpId: (connectionId) => sftpSessionsRef.current.get(connectionId),
+            acquireTransferSession: acquireTransferSession
+              ? (hostId, id) => acquireTransferSession(hostId, id)
+              : undefined,
+            startStreamTransfer: async (options) => {
+              const bridge = netcattyBridge.get();
+              if (!bridge?.startStreamTransfer) {
+                return { error: "Stream transfer is unavailable" };
+              }
+              return bridge.startStreamTransfer(options);
+            },
+            clearPendingCancel: (id) => netcattyBridge.get()?.clearPendingTransferCancel?.(id),
+            cleanupArtifacts: cleanupTaskArtifacts,
+            getTask: (id) => sftpTransferCenterStore.getTask(id)
+              ?? transfersRef.current.find((row) => row.id === id),
+            getChildTasks: (parentId) => {
+              const fromStore = sftpTransferCenterStore.getOwnerTasks(ownerId)
+                .filter((row) => row.parentTaskId === parentId);
+              if (fromStore.length > 0) return fromStore;
+              return transfersRef.current.filter((row) => row.parentTaskId === parentId);
+            },
+            onPatch: (taskId, updates) => {
+              transferRuntime.patchTask(taskId, updates);
+              setTransfers((prev) => {
+                if (!prev.some((row) => row.id === taskId)) {
+                  // Store-only child: mirror the patch by re-pulling owner rows.
+                  return sftpTransferCenterStore.getOwnerTasks(ownerId);
+                }
+                return prev.map((row) => (row.id === taskId ? { ...row, ...updates } : row));
+              });
+            },
+          });
+          if (!result.success && result.error && !/cancelled/i.test(result.error)) {
+            notify.warning(result.error, "SFTP");
+          }
+        } finally {
+          inFlightTransferIdsRef.current.delete(transferId);
+        }
+        return;
+      }
+
       await cleanupTaskArtifacts(task);
 
       const retriedTask: TransferTask = {
@@ -1316,7 +1374,13 @@ export const useSftpTransfers = ({
       };
 
       const endpoints = resolveTaskEndpoints(task);
-      if (!endpoints) return;
+      if (!endpoints) {
+        notify.warning(
+          "Could not resolve transfer endpoints for retry. Reconnect the target and try again.",
+          "SFTP",
+        );
+        return;
+      }
       const { targetSide, sourcePane, targetPane } = endpoints;
 
       const completionHandler = completionHandlersRef.current.get(transferId);
@@ -1335,7 +1399,7 @@ export const useSftpTransfers = ({
       await processTransfer(retriedTask, sourcePane, targetPane, targetSide);
     },
     // eslint-disable-next-line react-hooks/exhaustive-deps -- processTransfer is defined inline
-    [cleanupTaskArtifacts, resolveTaskEndpoints, setTransfers],
+    [acquireTransferSession, cleanupTaskArtifacts, ownerId, resolveTaskEndpoints, setTransfers, sftpSessionsRef],
   );
 
   const clearCompletedTransfers = useCallback(() => {

application/state/systemManager/useAsyncRecordCache.ts

@@ -0,0 +1,269 @@
+import { startTransition, useCallback, useEffect, useRef, useState } from 'react';
+
+export interface AsyncRecordState<T> {
+  data: T | null;
+  loading: boolean;
+  error: string | null;
+  updatedAt: number | null;
+}
+
+type RecordMap<T> = Record<string, AsyncRecordState<T>>;
+
+interface UseAsyncRecordCacheOptions<TItem, TValue> {
+  items: TItem[];
+  enabled: boolean;
+  getKey: (item: TItem) => string;
+  fetchRecord: (item: TItem) => Promise<TValue | null>;
+  prefetchLimit?: number;
+  prefetchDelayMs?: number;
+  staleTimeMs?: number;
+}
+
+function delay(ms: number): Promise<void> {
+  return new Promise((resolve) => window.setTimeout(resolve, ms));
+}
+
+function scheduleIdleTask(callback: () => void): () => void {
+  if (typeof window.requestIdleCallback === 'function') {
+    const id = window.requestIdleCallback(callback, { timeout: 1200 });
+    return () => window.cancelIdleCallback(id);
+  }
+
+  const id = window.setTimeout(callback, 80);
+  return () => window.clearTimeout(id);
+}
+
+function normalizeRecordError(error: unknown): string {
+  return error instanceof Error ? error.message : String(error || 'Unknown error');
+}
+
+function isRecordFresh<TValue>(record: AsyncRecordState<TValue> | undefined, staleTimeMs: number): boolean {
+  if (!record || record.error || record.updatedAt === null) return false;
+  if (!Number.isFinite(staleTimeMs)) return true;
+  return Date.now() - record.updatedAt < staleTimeMs;
+}
+
+const EMPTY_RECORDS = {};
+
+export function useAsyncRecordCache<TItem, TValue>({
+  items,
+  enabled,
+  getKey,
+  fetchRecord,
+  prefetchLimit = 64,
+  prefetchDelayMs = 16,
+  staleTimeMs = 30_000,
+}: UseAsyncRecordCacheOptions<TItem, TValue>) {
+  const [records, setRecords] = useState<RecordMap<TValue>>(() => EMPTY_RECORDS);
+  const recordsRef = useRef<RecordMap<TValue>>(records);
+  const enabledRef = useRef(enabled);
+  const inflightRef = useRef(new Set<string>());
+  const requestVersionRef = useRef(new Map<string, number>());
+  const queuedForceRef = useRef(new Set<string>());
+  const loadRecordRef = useRef<(
+    item: TItem,
+    options?: { force?: boolean; urgent?: boolean },
+  ) => Promise<void>>(async () => {});
+
+  recordsRef.current = records;
+  enabledRef.current = enabled;
+
+  const commitRecords = useCallback((
+    updater: (prev: RecordMap<TValue>) => RecordMap<TValue>,
+    urgent = false,
+  ) => {
+    const apply = () => {
+      setRecords((prev) => {
+        const next = updater(prev);
+        recordsRef.current = next;
+        return next;
+      });
+    };
+
+    if (urgent) {
+      apply();
+      return;
+    }
+
+    startTransition(apply);
+  }, []);
+
+  const loadRecord = useCallback(async (
+    item: TItem,
+    options?: { force?: boolean; urgent?: boolean },
+  ) => {
+    if (!enabledRef.current) return;
+    const key = getKey(item);
+    if (!key) return;
+    if (inflightRef.current.has(key)) {
+      if (options?.force) {
+        queuedForceRef.current.add(key);
+        requestVersionRef.current.set(key, (requestVersionRef.current.get(key) ?? 0) + 1);
+      }
+      return;
+    }
+
+    const existing = recordsRef.current[key];
+    if (!options?.force && isRecordFresh(existing, staleTimeMs)) {
+      return;
+    }
+
+    const requestVersion = (requestVersionRef.current.get(key) ?? 0) + 1;
+    requestVersionRef.current.set(key, requestVersion);
+    inflightRef.current.add(key);
+    commitRecords((prev) => ({
+      ...prev,
+      [key]: {
+        data: prev[key]?.data ?? null,
+        loading: true,
+        error: null,
+        updatedAt: prev[key]?.updatedAt ?? null,
+      },
+    }), options?.urgent);
+
+    try {
+      const data = await fetchRecord(item);
+      if (requestVersionRef.current.get(key) !== requestVersion) return;
+      commitRecords((prev) => ({
+        ...prev,
+        [key]: {
+          data,
+          loading: false,
+          error: null,
+          updatedAt: Date.now(),
+        },
+      }));
+    } catch (error) {
+      if (requestVersionRef.current.get(key) !== requestVersion) return;
+      commitRecords((prev) => ({
+        ...prev,
+        [key]: {
+          data: prev[key]?.data ?? null,
+          loading: false,
+          error: normalizeRecordError(error),
+          updatedAt: prev[key]?.updatedAt ?? null,
+        },
+      }));
+    } finally {
+      inflightRef.current.delete(key);
+      if (queuedForceRef.current.has(key)) {
+        if (enabledRef.current) {
+          queuedForceRef.current.delete(key);
+          void loadRecordRef.current(item, { force: true, urgent: options?.urgent });
+        } else {
+          commitRecords((prev) => {
+            const current = prev[key];
+            if (!current?.loading) return prev;
+            return {
+              ...prev,
+              [key]: {
+                ...current,
+                loading: false,
+              },
+            };
+          }, true);
+        }
+      }
+    }
+  }, [commitRecords, fetchRecord, getKey, staleTimeMs]);
+
+  loadRecordRef.current = loadRecord;
+
+  useEffect(() => {
+    const itemKeys = new Set(items.map(getKey).filter(Boolean));
+    for (const key of queuedForceRef.current) {
+      if (!itemKeys.has(key)) {
+        queuedForceRef.current.delete(key);
+      }
+    }
+    commitRecords((prev) => {
+      let changed = false;
+      const next: RecordMap<TValue> = {};
+      for (const [key, value] of Object.entries(prev) as Array<[string, AsyncRecordState<TValue>]>) {
+        if (!itemKeys.has(key)) {
+          changed = true;
+          continue;
+        }
+        next[key] = value;
+      }
+      return changed ? next : prev;
+    });
+  }, [commitRecords, getKey, items]);
+
+  useEffect(() => {
+    if (!enabled || queuedForceRef.current.size === 0) return;
+    for (const item of items) {
+      const key = getKey(item);
+      if (!key || !queuedForceRef.current.has(key)) continue;
+      queuedForceRef.current.delete(key);
+      void loadRecord(item, { force: true, urgent: true });
+    }
+  }, [enabled, getKey, items, loadRecord]);
+
+  useEffect(() => {
+    if (!enabled || items.length === 0 || prefetchLimit <= 0) return undefined;
+
+    let cancelled = false;
+    const candidates = items.slice(0, prefetchLimit);
+    const cancelIdleTask = scheduleIdleTask(() => {
+      void (async () => {
+        for (const item of candidates) {
+          if (cancelled) return;
+          await loadRecord(item);
+          if (prefetchDelayMs > 0) {
+            await delay(prefetchDelayMs);
+          }
+        }
+      })();
+    });
+
+    return () => {
+      cancelled = true;
+      cancelIdleTask();
+    };
+  }, [enabled, items, loadRecord, prefetchDelayMs, prefetchLimit]);
+
+  const invalidateRecord = useCallback((key: string) => {
+    requestVersionRef.current.set(key, (requestVersionRef.current.get(key) ?? 0) + 1);
+    queuedForceRef.current.delete(key);
+    commitRecords((prev) => {
+      if (!(key in prev)) return prev;
+      const { [key]: _removed, ...next } = prev;
+      return next;
+    }, true);
+  }, [commitRecords]);
+
+  const invalidateMatching = useCallback((matches: (key: string) => boolean) => {
+    for (const key of requestVersionRef.current.keys()) {
+      if (matches(key)) {
+        requestVersionRef.current.set(key, (requestVersionRef.current.get(key) ?? 0) + 1);
+        queuedForceRef.current.delete(key);
+      }
+    }
+    commitRecords((prev) => {
+      let changed = false;
+      const next: RecordMap<TValue> = {};
+      for (const [key, value] of Object.entries(prev) as Array<[string, AsyncRecordState<TValue>]>) {
+        if (matches(key)) {
+          changed = true;
+          continue;
+        }
+        next[key] = value;
+      }
+      return changed ? next : prev;
+    }, true);
+  }, [commitRecords]);
+
+  const refreshRecord = useCallback(
+    (item: TItem) => loadRecord(item, { force: true, urgent: true }),
+    [loadRecord],
+  );
+
+  return {
+    records,
+    loadRecord,
+    refreshRecord,
+    invalidateRecord,
+    invalidateMatching,
+  };
+}

application/state/systemSettingsEffects.ts

@@ -62,20 +62,25 @@ export function useSystemSettingsEffects({
   // Persist and sync toggle window hotkey setting
   useEffect(() => {
     if (!enabled) return;
+    let cancelled = false;
+    let didRegister = false;
     // Register/unregister the global hotkey in main process (needed on mount)
     const bridge = netcattyBridge.get();
     if (bridge?.registerGlobalHotkey) {
       if (toggleWindowHotkey && globalHotkeyEnabled) {
         setHotkeyRegistrationError(null);
+        didRegister = true;
         bridge
           .registerGlobalHotkey(toggleWindowHotkey)
           .then((result) => {
+            if (cancelled) return;
             if (result?.success === false) {
               console.warn('[GlobalHotkey] Hotkey registration failed:', result.error);
               setHotkeyRegistrationError(result.error || 'Failed to register hotkey');
             }
           })
           .catch((err) => {
+            if (cancelled) return;
             console.warn('[GlobalHotkey] Failed to register hotkey:', err);
             setHotkeyRegistrationError(err?.message || 'Failed to register hotkey');
           });
@@ -87,9 +92,20 @@ export function useSystemSettingsEffects({
       }
     }
     localStorageAdapter.writeString(STORAGE_KEY_TOGGLE_WINDOW_HOTKEY, toggleWindowHotkey);
-    // Skip IPC on initial mount
-    if (!persistMountedRef.current) return;
-    notifySettingsChanged(STORAGE_KEY_TOGGLE_WINDOW_HOTKEY, toggleWindowHotkey);
+    // Skip settings-sync IPC on initial mount; still return cleanup below.
+    if (persistMountedRef.current) {
+      notifySettingsChanged(STORAGE_KEY_TOGGLE_WINDOW_HOTKEY, toggleWindowHotkey);
+    }
+    return () => {
+      cancelled = true;
+      // Drop Mount1's registration before Mount2 re-registers (StrictMode), and
+      // release the accelerator on real unmount / disable transitions.
+      if (didRegister) {
+        bridge?.unregisterGlobalHotkey?.().catch((err) => {
+          console.warn('[GlobalHotkey] Failed to unregister hotkey on cleanup', err);
+        });
+      }
+    };
   }, [
     toggleWindowHotkey,
     enabled,

application/state/terminalSettingsStore.ts

@@ -0,0 +1,201 @@
+import { useSyncExternalStore } from 'react';
+
+import type {
+  HotkeyScheme,
+  KeyBinding,
+  SessionLogFormat,
+  TerminalSettings,
+} from '../../domain/models';
+import { normalizeTerminalSettings } from '../../domain/models';
+import type { useSettingsState } from './useSettingsState';
+
+type SettingsState = ReturnType<typeof useSettingsState>;
+
+type Listener = () => void;
+
+/**
+ * Terminal-facing settings slice. Mirrors `settingsChromeStore`: values and
+ * actions live on separate slots so setter identity churn never invalidates
+ * the value snapshot TerminalHost / terminal domain bags subscribe to.
+ */
+export type TerminalSettingsSnapshot = {
+  terminalThemeId: string;
+  terminalThemeDarkId: string;
+  terminalThemeLightId: string;
+  followAppTerminalTheme: boolean;
+  terminalFontFamilyId: string;
+  terminalFontSize: number;
+  terminalSettings: TerminalSettings;
+  hotkeyScheme: HotkeyScheme;
+  keyBindings: readonly KeyBinding[];
+  isHotkeyRecording: boolean;
+  sftpDoubleClickBehavior: 'open' | 'transfer';
+  sftpAutoSync: boolean;
+  sftpShowHiddenFiles: boolean;
+  sftpUseCompressedUpload: boolean;
+  sftpAutoOpenSidebar: boolean;
+  sftpFollowTerminalCwd: boolean;
+  sftpDefaultViewMode: 'list' | 'tree';
+  editorWordWrap: boolean;
+  sessionLogsEnabled: boolean;
+  sessionLogsDir: string;
+  sessionLogsFormat: SessionLogFormat;
+  sessionLogsTimestampsEnabled: boolean;
+  sshDebugLogsEnabled: boolean;
+};
+
+export type TerminalSettingsActions = Pick<
+  SettingsState,
+  | 'setTerminalThemeId'
+  | 'setTerminalThemeDarkId'
+  | 'setTerminalThemeLightId'
+  | 'setFollowAppTerminalTheme'
+  | 'setTerminalFontFamilyId'
+  | 'setTerminalFontSize'
+  | 'updateTerminalSetting'
+  | 'setSftpFollowTerminalCwd'
+  | 'setEditorWordWrap'
+  | 'applyAppTheme'
+>;
+
+export const DEFAULT_TERMINAL_SETTINGS_SNAPSHOT: TerminalSettingsSnapshot = Object.freeze({
+  terminalThemeId: 'default',
+  terminalThemeDarkId: 'default',
+  terminalThemeLightId: 'default',
+  followAppTerminalTheme: true,
+  terminalFontFamilyId: 'default',
+  terminalFontSize: 14,
+  terminalSettings: normalizeTerminalSettings(),
+  hotkeyScheme: 'mac',
+  keyBindings: Object.freeze([]) as readonly KeyBinding[],
+  isHotkeyRecording: false,
+  sftpDoubleClickBehavior: 'open',
+  sftpAutoSync: false,
+  sftpShowHiddenFiles: false,
+  sftpUseCompressedUpload: false,
+  sftpAutoOpenSidebar: false,
+  sftpFollowTerminalCwd: false,
+  sftpDefaultViewMode: 'list',
+  editorWordWrap: true,
+  sessionLogsEnabled: false,
+  sessionLogsDir: '',
+  sessionLogsFormat: 'txt',
+  sessionLogsTimestampsEnabled: false,
+  sshDebugLogsEnabled: false,
+});
+
+export function terminalSettingsSnapshotsEqual(
+  a: TerminalSettingsSnapshot,
+  b: TerminalSettingsSnapshot,
+): boolean {
+  return a.terminalThemeId === b.terminalThemeId
+    && a.terminalThemeDarkId === b.terminalThemeDarkId
+    && a.terminalThemeLightId === b.terminalThemeLightId
+    && a.followAppTerminalTheme === b.followAppTerminalTheme
+    && a.terminalFontFamilyId === b.terminalFontFamilyId
+    && a.terminalFontSize === b.terminalFontSize
+    && a.terminalSettings === b.terminalSettings
+    && a.hotkeyScheme === b.hotkeyScheme
+    && a.keyBindings === b.keyBindings
+    && a.isHotkeyRecording === b.isHotkeyRecording
+    && a.sftpDoubleClickBehavior === b.sftpDoubleClickBehavior
+    && a.sftpAutoSync === b.sftpAutoSync
+    && a.sftpShowHiddenFiles === b.sftpShowHiddenFiles
+    && a.sftpUseCompressedUpload === b.sftpUseCompressedUpload
+    && a.sftpAutoOpenSidebar === b.sftpAutoOpenSidebar
+    && a.sftpFollowTerminalCwd === b.sftpFollowTerminalCwd
+    && a.sftpDefaultViewMode === b.sftpDefaultViewMode
+    && a.editorWordWrap === b.editorWordWrap
+    && a.sessionLogsEnabled === b.sessionLogsEnabled
+    && a.sessionLogsDir === b.sessionLogsDir
+    && a.sessionLogsFormat === b.sessionLogsFormat
+    && a.sessionLogsTimestampsEnabled === b.sessionLogsTimestampsEnabled
+    && a.sshDebugLogsEnabled === b.sshDebugLogsEnabled;
+}
+
+class TerminalSettingsStore {
+  private snapshot: TerminalSettingsSnapshot = DEFAULT_TERMINAL_SETTINGS_SNAPSHOT;
+  private actions: TerminalSettingsActions | null = null;
+  private listeners = new Set<Listener>();
+  private actionListeners = new Set<Listener>();
+
+  getSnapshot = (): TerminalSettingsSnapshot => this.snapshot;
+
+  subscribe = (listener: Listener): (() => void) => {
+    this.listeners.add(listener);
+    return () => {
+      this.listeners.delete(listener);
+    };
+  };
+
+  setSnapshot(next: TerminalSettingsSnapshot): void {
+    if (terminalSettingsSnapshotsEqual(this.snapshot, next)) return;
+    this.snapshot = next;
+    for (const listener of this.listeners) {
+      listener();
+    }
+  }
+
+  getActions = (): TerminalSettingsActions | null => this.actions;
+
+  subscribeActions = (listener: Listener): (() => void) => {
+    this.actionListeners.add(listener);
+    return () => {
+      this.actionListeners.delete(listener);
+    };
+  };
+
+  setActions(next: TerminalSettingsActions | null): void {
+    if (this.actions === next) return;
+    this.actions = next;
+    for (const listener of this.actionListeners) {
+      listener();
+    }
+  }
+}
+
+export const terminalSettingsStore = new TerminalSettingsStore();
+
+export function publishTerminalSettingsSnapshot(
+  snapshot: TerminalSettingsSnapshot,
+): void {
+  terminalSettingsStore.setSnapshot(snapshot);
+}
+
+export function getTerminalSettingsSnapshot(): TerminalSettingsSnapshot {
+  return terminalSettingsStore.getSnapshot();
+}
+
+export function subscribeTerminalSettings(listener: Listener): () => void {
+  return terminalSettingsStore.subscribe(listener);
+}
+
+export function registerTerminalSettingsActions(
+  actions: TerminalSettingsActions | null,
+): void {
+  terminalSettingsStore.setActions(actions);
+}
+
+export function getTerminalSettingsActions(): TerminalSettingsActions | null {
+  return terminalSettingsStore.getActions();
+}
+
+export function subscribeTerminalSettingsActions(listener: Listener): () => void {
+  return terminalSettingsStore.subscribeActions(listener);
+}
+
+export function useTerminalSettingsStore(): TerminalSettingsSnapshot {
+  return useSyncExternalStore(
+    subscribeTerminalSettings,
+    getTerminalSettingsSnapshot,
+    getTerminalSettingsSnapshot,
+  );
+}
+
+export function useTerminalSettingsActions(): TerminalSettingsActions | null {
+  return useSyncExternalStore(
+    subscribeTerminalSettingsActions,
+    getTerminalSettingsActions,
+    getTerminalSettingsActions,
+  );
+}

application/state/useAIChatStreaming.architecture.test.ts

@@ -0,0 +1,10 @@
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import test from "node:test";
+
+const source = readFileSync(new URL("./useAIChatStreaming.ts", import.meta.url), "utf8");
+
+test("useAIChatStreaming imports streaming support from infrastructure", () => {
+  assert.match(source, /from ['"]\.\.\/\.\.\/infrastructure\/ai\/aiChatStreamingSupport['"]/);
+  assert.doesNotMatch(source, /from ['"].*components\//);
+});

application/state/useAIChatStreaming.ts

@@ -0,0 +1,268 @@
+/**
+ * useAIChatStreaming — React UI layer for AI chat streaming.
+ *
+ * Turn orchestration lives in AgentRuntime + TurnDrivers; this hook only
+ * manages streaming state, abort controllers, and UI callbacks.
+ */
+
+import React, { useCallback, useEffect, useRef, useState } from 'react';
+import type {
+  AIPermissionMode,
+  AIToolIntegrationMode,
+  AISession,
+  ChatMessage,
+  ChatMessageAttachment,
+  ExternalAgentConfig,
+  ProviderConfig,
+  WebSearchConfig,
+} from '../../infrastructure/ai/types';
+import type { ExecutorContext } from '../../infrastructure/ai/cattyAgent/executor';
+import { getAgentRuntime } from '../../infrastructure/ai/harness/globalAgentRuntime';
+import type {
+  TurnSteerInput,
+  TurnSteerResult,
+} from '../../infrastructure/ai/harness/turnDrivers/types';
+import { classifyError } from '../../infrastructure/ai/errorClassifier';
+import { latestAISessionsSnapshot } from './aiStateSnapshots';
+import {
+  generateId,
+  getNetcattyBridge,
+  type DefaultTargetSessionHint,
+  type TerminalSessionInfo,
+} from '../../infrastructure/ai/aiChatStreamingSupport';
+import { useAgentCompactionUi } from './useAgentCompactionUi';
+
+export { getNetcattyBridge } from '../../infrastructure/ai/aiChatStreamingSupport';
+export type { ActiveCompactionUi } from './useAgentCompactionUi';
+export type { DefaultTargetSessionHint } from '../../infrastructure/ai/aiChatStreamingSupport';
+
+const sharedStreamingSessionIds = new Set<string>();
+const sharedAbortControllers = new Map<string, AbortController>();
+const streamingSubscribers = new Set<() => void>();
+
+/** Whether a chat session still has an active stream (used to keep panel mounted while hidden). */
+export function isAIChatSessionStreaming(sessionId: string | null | undefined): boolean {
+  return !!sessionId && sharedStreamingSessionIds.has(sessionId);
+}
+
+function emitStreamingStoreChange(): void {
+  streamingSubscribers.forEach(listener => {
+    try {
+      listener();
+    } catch (err) {
+      console.error('[AIChatStreaming] Failed to notify streaming subscriber:', err);
+    }
+  });
+}
+
+export interface UseAIChatStreamingParams {
+  maxIterations: number;
+  addMessageToSession: (sessionId: string, message: ChatMessage) => void;
+  updateLastMessage: (sessionId: string, updater: (msg: ChatMessage) => ChatMessage) => void;
+  updateMessageById: (sessionId: string, messageId: string, updater: (msg: ChatMessage) => ChatMessage) => void;
+  persistContextCompaction?: (
+    sessionId: string,
+    compaction: import('../../infrastructure/ai/types').AISessionContextCompaction,
+  ) => void;
+}
+
+export interface UseAIChatStreamingReturn {
+  streamingSessionIds: Set<string>;
+  setStreamingForScope: (key: string, val: boolean) => void;
+  abortControllersRef: React.MutableRefObject<Map<string, AbortController>>;
+  sendToCattyAgent: (
+    sessionId: string,
+    sendScopeKey: string,
+    trimmed: string,
+    abortController: AbortController,
+    currentSession: AISession | undefined,
+    assistantMsgId: string,
+    context: SendToCattyContext,
+    attachments?: ChatMessageAttachment[],
+  ) => Promise<void>;
+  sendToExternalAgent: (
+    sessionId: string,
+    assistantMsgId: string,
+    trimmed: string,
+    agentConfig: ExternalAgentConfig,
+    abortController: AbortController,
+    attachedImages: Array<{ base64Data: string; mediaType: string; filename?: string; filePath?: string }>,
+    context: SendToExternalContext,
+  ) => Promise<void>;
+  steerExternalAgent: (input: TurnSteerInput) => Promise<TurnSteerResult>;
+  reportStreamError: (sessionId: string, abortSignal: AbortSignal, err: unknown) => void;
+  activeCompaction: import('./useAgentCompactionUi').ActiveCompactionUi | null;
+}
+
+export interface SendToCattyContext {
+  activeProvider: ProviderConfig | undefined;
+  activeModelId: string;
+  scopeType: 'terminal' | 'workspace';
+  scopeTargetId?: string;
+  scopeLabel?: string;
+  globalPermissionMode: AIPermissionMode;
+  commandBlocklist?: string[];
+  commandTimeout?: number;
+  terminalSessions: TerminalSessionInfo[];
+  webSearchConfig?: WebSearchConfig | null;
+  getExecutorContext?: () => ExecutorContext;
+  autoTitleSession: (sessionId: string, text: string) => void;
+  titleText?: string;
+  selectedUserSkillSlugs?: string[];
+  permissionMode?: AIPermissionMode;
+  forceCompaction?: boolean;
+}
+
+export interface SendToExternalContext {
+  existingSessionId?: string;
+  updateExternalSessionId?: (sessionId: string, externalSessionId: string | undefined) => void;
+  historyMessages?: Array<{ role: 'user' | 'assistant'; content: string }>;
+  terminalSessions: TerminalSessionInfo[];
+  defaultTargetSession?: DefaultTargetSessionHint;
+  providers: ProviderConfig[];
+  selectedAgentModel?: string;
+  toolIntegrationMode: AIToolIntegrationMode;
+  selectedUserSkillSlugs?: string[];
+  permissionMode: AIPermissionMode;
+}
+
+export function useAIChatStreaming({
+  maxIterations,
+  addMessageToSession,
+  updateLastMessage,
+  updateMessageById,
+  persistContextCompaction,
+}: UseAIChatStreamingParams): UseAIChatStreamingReturn {
+  const [streamingSessionIds, setStreamingSessions] = useState<Set<string>>(
+    () => new Set(sharedStreamingSessionIds),
+  );
+
+  useEffect(() => {
+    const syncFromStore = () => {
+      setStreamingSessions(new Set(sharedStreamingSessionIds));
+    };
+    streamingSubscribers.add(syncFromStore);
+    syncFromStore();
+    return () => {
+      streamingSubscribers.delete(syncFromStore);
+    };
+  }, []);
+
+  const setStreamingForScope = useCallback((key: string, val: boolean) => {
+    const hadKey = sharedStreamingSessionIds.has(key);
+    if (val) {
+      sharedStreamingSessionIds.add(key);
+    } else {
+      sharedStreamingSessionIds.delete(key);
+    }
+    if (hadKey !== val) {
+      emitStreamingStoreChange();
+    }
+  }, []);
+
+  const abortControllersRef = useRef<Map<string, AbortController>>(sharedAbortControllers);
+
+  const activeCompaction = useAgentCompactionUi();
+
+  const reportStreamError = useCallback((
+    sessionId: string,
+    abortSignal: AbortSignal,
+    err: unknown,
+  ) => {
+    if (abortSignal.aborted) return;
+    console.error('[AIChatSidePanel] Stream error (full):', err);
+    const errorInfo = classifyError(err);
+    updateLastMessage(sessionId, msg => ({
+      ...msg,
+      statusText: '',
+      executionStatus: msg.executionStatus === 'running' ? 'failed' : msg.executionStatus,
+    }));
+    addMessageToSession(sessionId, {
+      id: generateId(),
+      role: 'assistant',
+      content: '',
+      errorInfo,
+      timestamp: Date.now(),
+    });
+  }, [updateLastMessage, addMessageToSession]);
+
+  const uiCallbacks = useCallback(() => ({
+    addMessageToSession,
+    updateLastMessage,
+    updateMessageById,
+    reportStreamError,
+    setStreamingForScope,
+    getLatestSession: (sessionId: string) => latestAISessionsSnapshot?.find(s => s.id === sessionId),
+    persistContextCompaction,
+  }), [addMessageToSession, updateLastMessage, updateMessageById, reportStreamError, setStreamingForScope, persistContextCompaction]);
+
+  const sendToExternalAgent = useCallback(async (
+    sessionId: string,
+    assistantMsgId: string,
+    trimmed: string,
+    agentConfig: ExternalAgentConfig,
+    abortController: AbortController,
+    attachedImages: Array<{ base64Data: string; mediaType: string; filename?: string; filePath?: string }>,
+    context: SendToExternalContext,
+  ) => {
+    const bridge = getNetcattyBridge();
+    await getAgentRuntime().runTurn({
+      backend: 'external-sdk',
+      chatSessionId: sessionId,
+      assistantMsgId,
+      userText: trimmed,
+      signal: abortController.signal,
+      agentConfig,
+      attachedImages,
+      context,
+      bridge,
+      ui: uiCallbacks(),
+    });
+  }, [uiCallbacks]);
+
+  const steerExternalAgent = useCallback(async (input: TurnSteerInput) => {
+    return getAgentRuntime().steerTurn(input);
+  }, []);
+
+  const sendToCattyAgent = useCallback(async (
+    sessionId: string,
+    sendScopeKey: string,
+    trimmed: string,
+    abortController: AbortController,
+    currentSession: AISession | undefined,
+    assistantMsgId: string,
+    context: SendToCattyContext,
+    attachments?: ChatMessageAttachment[],
+  ) => {
+    const bridge = getNetcattyBridge();
+    try {
+      await getAgentRuntime().runTurn({
+        backend: 'catty',
+        chatSessionId: sessionId,
+        sendScopeKey,
+        userText: trimmed,
+        signal: abortController.signal,
+        currentSession,
+        assistantMsgId,
+        context,
+        attachments,
+        maxIterations,
+        bridge,
+        ui: uiCallbacks(),
+      });
+    } finally {
+      abortControllersRef.current.delete(sessionId);
+    }
+  }, [maxIterations, uiCallbacks]);
+
+  return {
+    streamingSessionIds,
+    setStreamingForScope,
+    abortControllersRef,
+    sendToCattyAgent,
+    sendToExternalAgent,
+    steerExternalAgent,
+    reportStreamError,
+    activeCompaction,
+  };
+}

application/state/useAIState.ts

@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
+import { useCallback, useEffect, useLayoutEffect, useMemo, useRef, useState } from 'react';
 import { localStorageAdapter } from '../../infrastructure/persistence/localStorageAdapter';
 import {
   STORAGE_KEY_AI_PROVIDERS,
@@ -50,6 +50,7 @@ import {
 } from './aiDraftState';
 import { convertFilesToUploads } from './useFileUpload';
 import { removeProviderReferences } from './aiProviderCleanup';
+import { publishAISessionsSnapshot } from './aiSessionsStore';
 import {
   AI_STATE_CHANGED_DRAFTS_BY_SCOPE,
   AI_STATE_CHANGED_PANEL_VIEW_BY_SCOPE,
@@ -1004,6 +1005,17 @@ export function useAIState() {
   // ── Computed ──
   const activeProvider = providers.find(p => p.id === activeProviderId) ?? null;
 
+  // Stream/message updates publish here so AIConfig Context consumers do not
+  // re-render on every token. AIChatPanelsHost reads aiSessionsStore instead.
+  useLayoutEffect(() => {
+    publishAISessionsSnapshot({
+      sessions,
+      activeSessionIdMap,
+      draftsByScope,
+      panelViewByScope,
+    });
+  }, [sessions, activeSessionIdMap, draftsByScope, panelViewByScope]);
+
   return useMemo(() => ({
     providers,
     setProviders,
@@ -1039,10 +1051,8 @@ export function useAIState() {
     setWebSearchConfig,
     quickMessages,
     setQuickMessages,
-    sessions,
-    activeSessionIdMap,
-    draftsByScope,
-    panelViewByScope,
+    // sessions / activeSessionIdMap / draftsByScope / panelViewByScope live in
+    // aiSessionsStore so streaming updates do not rebuild this config object.
     setActiveSessionId,
     ensureDraftForScope,
     updateDraft,
@@ -1096,10 +1106,6 @@ export function useAIState() {
     setWebSearchConfig,
     quickMessages,
     setQuickMessages,
-    sessions,
-    activeSessionIdMap,
-    draftsByScope,
-    panelViewByScope,
     setActiveSessionId,
     ensureDraftForScope,
     updateDraft,

application/state/useAgentCompactionUi.ts

@@ -0,0 +1,95 @@
+import { useEffect, useState } from 'react';
+import type { ContextPrepareTrigger } from '../../infrastructure/ai/harness/types';
+import { getAgentRuntime } from '../../infrastructure/ai/harness/globalAgentRuntime';
+import { CATTY_COMPACTION_STATUS_KEYS } from '../../infrastructure/ai/harness/compactionStatusKeys';
+
+export interface ActiveCompactionUi {
+  sessionId: string;
+  trigger: ContextPrepareTrigger;
+}
+
+export interface AgentContextUsage {
+  sessionId: string;
+  inputTokens: number;
+  contextWindow: number;
+  estimated: boolean;
+}
+
+function statusKeyForTrigger(trigger: ContextPrepareTrigger): string {
+  switch (trigger) {
+    case 'step':
+      return CATTY_COMPACTION_STATUS_KEYS.step;
+    case '413-retry':
+      return CATTY_COMPACTION_STATUS_KEYS.retry;
+    default:
+      return CATTY_COMPACTION_STATUS_KEYS.preTurn;
+  }
+}
+
+export function useAgentCompactionUi(): ActiveCompactionUi | null {
+  const [active, setActive] = useState<ActiveCompactionUi | null>(null);
+
+  useEffect(() => {
+    const unsubscribe = getAgentRuntime().subscribe((event) => {
+      const sessionId = event.chatSessionId ?? event.sessionId;
+      if (event.type === 'compaction_start') {
+        setActive({ sessionId, trigger: event.trigger });
+        return;
+      }
+      if (event.type === 'compaction' || event.type === 'turn_end') {
+        setActive((prev) => (prev?.sessionId === sessionId ? null : prev));
+      }
+    });
+    return unsubscribe;
+  }, []);
+
+  return active;
+}
+
+export function compactionStatusText(
+  trigger: ContextPrepareTrigger,
+  translate: (key: string, params?: Record<string, string | number>) => string,
+): string {
+  return translate(statusKeyForTrigger(trigger));
+}
+
+export function resolveCompactionStatusText(
+  statusText: string | undefined,
+  translate: (key: string) => string,
+): string | undefined {
+  if (!statusText) return undefined;
+  if (statusText.startsWith('ai.')) return translate(statusText);
+  return statusText;
+}
+
+export function useAgentContextUsage(sessionId: string | null | undefined): AgentContextUsage | null {
+  const [usage, setUsage] = useState<AgentContextUsage | null>(null);
+
+  useEffect(() => {
+    if (!sessionId) {
+      setUsage(null);
+      return undefined;
+    }
+
+    const unsubscribe = getAgentRuntime().subscribe((event) => {
+      const eventSessionId = event.chatSessionId ?? event.sessionId;
+      if (eventSessionId !== sessionId || event.type !== 'context_snapshot') return;
+      const snapshot = event.snapshot;
+      if (
+        typeof snapshot.contextWindow !== 'number'
+        || typeof snapshot.estimatedInputTokens !== 'number'
+      ) {
+        return;
+      }
+      setUsage({
+        sessionId,
+        inputTokens: Math.max(0, snapshot.estimatedInputTokens),
+        contextWindow: Math.max(1, snapshot.contextWindow),
+        estimated: true,
+      });
+    });
+    return unsubscribe;
+  }, [sessionId]);
+
+  return usage?.sessionId === sessionId ? usage : null;
+}

application/state/useAutoSync.ts

@@ -7,7 +7,7 @@
  * - Debounced sync to avoid too frequent API calls
  */
 
-import { useCallback, useEffect, useRef, useState } from 'react';
+import { useCallback, useEffect, useRef, useState, useSyncExternalStore } from 'react';
 import { useCloudSync } from './useCloudSync';
 import { useI18n } from '../i18n/I18nProvider';
 import { getCloudSyncManager } from '../../infrastructure/services/CloudSyncManager';
@@ -49,6 +49,7 @@ import {
   shouldRunRuntimeRemoteCheck,
 } from './autoSyncRemoteSchedule';
 import { resolveAutoSyncHashDecision } from './autoSyncHashDecision';
+import { getNotesSnapshot, subscribeNotes } from './notesStore';
 
 interface AutoSyncConfig {
   enabled?: boolean;
@@ -163,6 +164,9 @@ interface RemoteVersionCheckOptions {
 
 export const useAutoSync = (config: AutoSyncConfig) => {
   const enabled = config.enabled !== false;
+  // Subscribe so note edits still trigger getSyncSnapshot rebuilds even when
+  // App omits notes props (notes live in notesStore, not App render).
+  const notesSnapshot = useSyncExternalStore(subscribeNotes, getNotesSnapshot, getNotesSnapshot);
   const { t } = useI18n();
   const tRef = useRef(t);
   useEffect(() => {
@@ -254,8 +258,10 @@ export const useAutoSync = (config: AutoSyncConfig) => {
       snippets: config.snippets,
       customGroups: config.customGroups,
       snippetPackages: config.snippetPackages,
-      notes: config.notes,
-      noteGroups: config.noteGroups,
+      // Prefer explicit overrides (tests); otherwise read the live notes store so
+      // App does not have to re-render on every note edit to keep sync current.
+      notes: config.notes ?? (notesSnapshot.notes as SyncPayload['notes']),
+      noteGroups: config.noteGroups ?? (notesSnapshot.noteGroups as SyncPayload['noteGroups']),
       portForwardingRules: getEffectivePortForwardingRulesForSync(config.portForwardingRules),
       groupConfigs: config.groupConfigs,
     };
@@ -271,6 +277,8 @@ export const useAutoSync = (config: AutoSyncConfig) => {
     config.noteGroups,
     config.portForwardingRules,
     config.groupConfigs,
+    notesSnapshot.notes,
+    notesSnapshot.noteGroups,
   ]);
 
   // Build sync payload (includes plugin sidecars when host is available)
@@ -495,7 +503,7 @@ export const useAutoSync = (config: AutoSyncConfig) => {
     } finally {
       isSyncRunningRef.current = false;
     }
-  }, [enabled, sync, buildPayload, getDataHash, onApplyConvergentPayload, onApplyPayload, t]);
+  }, [enabled, sync, buildPayload, onApplyConvergentPayload, onApplyPayload, t]);
 
   const syncNowRef = useRef(syncNow);
   useEffect(() => {

application/state/useExternalMcpSessionSync.ts

@@ -1,6 +1,6 @@
 import { useEffect, useMemo, useRef, useState } from 'react';
 
-import { buildAITerminalSessionInfo } from '../../components/terminalLayer/TerminalLayerSupport';
+import { buildAITerminalSessionInfo } from '../../domain/buildAITerminalSessionInfo';
 import { detectLocalOs } from '../../lib/localShell';
 import type { Host, PortForwardingRule, TerminalSession } from '../../types';
 import { STORAGE_KEY_AI_EXTERNAL_MCP_ENABLED } from '../../infrastructure/config/storageKeys';

application/state/useExternalMcpToggleState.test.ts

@@ -15,9 +15,11 @@ import {
   readExternalMcpSilentSessions,
   readExternalMcpStoredEnabled,
   resetExternalMcpStartupReadyForTests,
+  resetExternalMcpStartupSyncOnceForTests,
   shouldStartExternalMcpOnStartup,
   shouldWaitForExternalMcpStartupReady,
   syncExternalMcpStartupState,
+  syncExternalMcpStartupStateOnce,
   waitForExternalMcpStartupReady,
   writeExternalMcpFocusOnHostOpen,
   writeExternalMcpSilentSessions,
@@ -178,17 +180,17 @@ describe('useExternalMcpToggleState startup ready gate', () => {
 
   it('wires App startup reconcile to release the gate after enable settles', async () => {
     const appSource = await import('node:fs').then((fs) =>
-      fs.readFileSync(new URL('../../App.tsx', import.meta.url), 'utf8'),
+      fs.readFileSync(new URL('../app/AppSideEffects.tsx', import.meta.url), 'utf8'),
     );
     const hookSource = await import('node:fs').then((fs) =>
       fs.readFileSync(new URL('./useExternalMcpToggleState.ts', import.meta.url), 'utf8'),
     );
-    assert.match(appSource, /await syncExternalMcpStartupState\(netcattyBridge\.get\(\)\)/);
+    assert.match(appSource, /await syncExternalMcpStartupStateOnce\(netcattyBridge\.get\(\)\)/);
     assert.match(appSource, /markExternalMcpStartupReady\(\)/);
     assert.ok(
-      appSource.indexOf('await syncExternalMcpStartupState(netcattyBridge.get())')
+      appSource.indexOf('await syncExternalMcpStartupStateOnce(netcattyBridge.get())')
         < appSource.indexOf('markExternalMcpStartupReady()'),
-      'startup ready must be marked only after await syncExternalMcpStartupState',
+      'startup ready must be marked only after await syncExternalMcpStartupStateOnce',
     );
     assert.match(hookSource, /export async function syncExternalMcpStartupState/);
     assert.match(hookSource, /await Promise\.resolve\(bridge\?\.externalMcpSetEnabled\?\.\(plan\.runtimeEnabled\)\)/);
@@ -247,6 +249,51 @@ describe('useExternalMcpToggleState startup ready gate', () => {
   });
 });
 
+describe('syncExternalMcpStartupStateOnce single-flight', () => {
+  it('reaches the bridge once when the startup effect is invoked twice', async () => {
+    const restore = installMemoryLocalStorage();
+    try {
+      resetExternalMcpStartupReadyForTests();
+      resetExternalMcpStartupSyncOnceForTests();
+      const storageKeys = await import('../../infrastructure/config/storageKeys.ts');
+      globalThis.localStorage.setItem(storageKeys.STORAGE_KEY_AI_EXTERNAL_MCP_ENABLED, 'true');
+      globalThis.localStorage.setItem(storageKeys.STORAGE_KEY_AI_EXTERNAL_MCP_MODE, 'persistent');
+
+      const configCalls: unknown[] = [];
+      const enabledCalls: boolean[] = [];
+      const bridge = {
+        externalMcpSetConfig: async (config: unknown) => {
+          configCalls.push(config);
+          return { ok: true };
+        },
+        externalMcpSetEnabled: async (enabled: boolean) => {
+          enabledCalls.push(enabled);
+          return { ok: true, enabled };
+        },
+      };
+
+      // Mount, cleanup, mount again: both effect runs share one reconcile.
+      const first = syncExternalMcpStartupStateOnce(bridge);
+      const second = syncExternalMcpStartupStateOnce(bridge);
+      assert.equal(first, second);
+
+      const [firstPlan, secondPlan] = await Promise.all([first, second]);
+      assert.equal(firstPlan, secondPlan);
+      assert.equal(firstPlan.runtimeEnabled, true);
+      assert.equal(configCalls.length, 1);
+      assert.deepEqual(enabledCalls, [true]);
+
+      // A later remount awaits the settled promise instead of re-sending IPC.
+      await syncExternalMcpStartupStateOnce(bridge);
+      assert.equal(configCalls.length, 1);
+      assert.deepEqual(enabledCalls, [true]);
+    } finally {
+      resetExternalMcpStartupSyncOnceForTests();
+      restore();
+    }
+  });
+});
+
 describe('syncExternalMcpStartupState generation guard', () => {
   it('skips stale startup enable after concurrent top-bar toggle generation bump', async () => {
     const restore = installMemoryLocalStorage();

application/state/useExternalMcpToggleState.ts

@@ -64,6 +64,7 @@ export function resetExternalMcpStartupReadyForTests(): void {
   externalMcpStartupReadyWaitPromise = null;
   externalMcpStartupReadyWaitResolve = null;
   externalMcpEnableGeneration = 0;
+  externalMcpStartupSyncPromise = null;
 }
 
 export function getExternalMcpEnableGenerationForTests(): number {
@@ -144,12 +145,26 @@ export function readExternalMcpMode(): ExternalMcpMode {
   return normalizeExternalMcpMode(localStorageAdapter.readString(STORAGE_KEY_AI_EXTERNAL_MCP_MODE));
 }
 
+export function writeExternalMcpMode(mode: ExternalMcpMode): ExternalMcpMode {
+  const normalized = normalizeExternalMcpMode(mode);
+  localStorageAdapter.writeString(STORAGE_KEY_AI_EXTERNAL_MCP_MODE, normalized);
+  emitAIStateChanged(STORAGE_KEY_AI_EXTERNAL_MCP_MODE);
+  return normalized;
+}
+
 export function readExternalMcpIdleTimeoutMinutes(): number {
   return normalizeExternalMcpIdleTimeoutMinutes(
     localStorageAdapter.readNumber(STORAGE_KEY_AI_EXTERNAL_MCP_IDLE_TIMEOUT_MINUTES),
   );
 }
 
+export function writeExternalMcpIdleTimeoutMinutes(minutes: number): number {
+  const normalized = normalizeExternalMcpIdleTimeoutMinutes(minutes);
+  localStorageAdapter.writeNumber(STORAGE_KEY_AI_EXTERNAL_MCP_IDLE_TIMEOUT_MINUTES, normalized);
+  emitAIStateChanged(STORAGE_KEY_AI_EXTERNAL_MCP_IDLE_TIMEOUT_MINUTES);
+  return normalized;
+}
+
 /** Whether host_open should surface/focus the main window. Defaults to true (existing behavior). */
 export function readExternalMcpFocusOnHostOpen(): boolean {
   return localStorageAdapter.readBoolean(STORAGE_KEY_AI_EXTERNAL_MCP_FOCUS_ON_HOST_OPEN) ?? true;
@@ -187,6 +202,13 @@ export function readSessionIdleTimeoutMinutes(): number {
   );
 }
 
+export function writeSessionIdleTimeoutMinutes(minutes: number): number {
+  const normalized = normalizeSessionIdleTimeoutMinutes(minutes);
+  localStorageAdapter.writeNumber(STORAGE_KEY_AI_SESSION_IDLE_TIMEOUT_MINUTES, normalized);
+  emitAIStateChanged(STORAGE_KEY_AI_SESSION_IDLE_TIMEOUT_MINUTES);
+  return normalized;
+}
+
 export function shouldStartExternalMcpOnStartup({
   enabled,
   mode,
@@ -289,6 +311,26 @@ export async function syncExternalMcpStartupState(
   return plan;
 }
 
+let externalMcpStartupSyncPromise: Promise<ExternalMcpStartupSyncPlan> | null = null;
+
+/**
+ * Startup reconcile runs exactly once per renderer load. A remounted App must
+ * await the same settled promise instead of pushing a second enable/disable to
+ * the main process, which would fight the user's live toggle.
+ */
+export function syncExternalMcpStartupStateOnce(
+  bridge: ExternalMcpBridge | undefined = netcattyBridge.get(),
+): Promise<ExternalMcpStartupSyncPlan> {
+  if (!externalMcpStartupSyncPromise) {
+    externalMcpStartupSyncPromise = syncExternalMcpStartupState(bridge);
+  }
+  return externalMcpStartupSyncPromise;
+}
+
+export function resetExternalMcpStartupSyncOnceForTests(): void {
+  externalMcpStartupSyncPromise = null;
+}
+
 export function useExternalMcpToggleState() {
   // UI mirrors the stored switch. Startup reconcile (App mount, main window only)
   // decides whether temporary mode should clear/persist and start the runtime.

application/state/useManualTerminalChromeSurfaceInjection.test.ts

@@ -2,7 +2,11 @@ import assert from 'node:assert/strict';
 import { readFileSync } from 'node:fs';
 import test from 'node:test';
 
-const appSource = readFileSync(new URL('../../App.tsx', import.meta.url), 'utf8');
+const appSource = [
+  readFileSync(new URL('../app/AppSideEffects.tsx', import.meta.url), 'utf8'),
+  readFileSync(new URL('../app/hosts/TerminalHost.tsx', import.meta.url), 'utf8'),
+  readFileSync(new URL('../app/hosts/ChromeHost.tsx', import.meta.url), 'utf8'),
+].join('\n');
 const hookSource = readFileSync(new URL('./useManualTerminalChromeSurfaceInjection.ts', import.meta.url), 'utf8');
 const bridgeSource = readFileSync(new URL('../../components/terminalLayer/TerminalLayerTabBridge.tsx', import.meta.url), 'utf8');
 const varsSource = readFileSync(new URL('../../infrastructure/theme/terminalAppearanceVars.ts', import.meta.url), 'utf8');
@@ -12,7 +16,9 @@ test('manual mode injects chrome surfaces from focused session theme', () => {
   assert.match(bridgeSource, /useManualTerminalChromeSurfaceInjection/);
   assert.match(bridgeSource, /!s\.followAppTerminalTheme && isTerminalLayerVisible/);
   assert.match(readFileSync(new URL('../app/AppHostTreeLayer.tsx', import.meta.url), 'utf8'), /useManualTerminalChromeSurfaceInjection/);
-  assert.match(appSource, /resolveSessionAppearance=\{resolveFocusedAppearance\}/);
+  // App feeds the focused-session resolver to AppActiveTabChrome through the
+  // memoized shell chrome bag (AppShell spreads it onto the chrome component).
+  assert.match(appSource, /resolveSessionAppearance: resolveFocusedAppearance/);
   assert.match(hookSource, /applyTopTabsChromeThemeVars\(theme\)/);
   assert.match(hookSource, /injectTerminalLayerChromeSurfaceVars\(theme\)/);
   assert.match(hookSource, /if \(wasEnabled\) \{[\s\S]*clearTerminalLayerChromeSurfaceVars\(\)/);

application/state/usePortForwardHostKeyVerification.architecture.test.ts

@@ -0,0 +1,10 @@
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import test from "node:test";
+
+const source = readFileSync(new URL("./usePortForwardHostKeyVerification.ts", import.meta.url), "utf8");
+
+test("usePortForwardHostKeyVerification stays below the UI layer", () => {
+  assert.doesNotMatch(source, /from ["'].*components\//);
+  assert.match(source, /from ["']\.\.\/\.\.\/domain\/portForwardHostKey["']/);
+});

application/state/usePortForwardHostKeyVerification.ts

@@ -1,7 +1,7 @@
 import { useCallback, useEffect, useState } from "react";
 import type { KnownHost } from "../../domain/models";
 import { netcattyBridge } from "../../infrastructure/services/netcattyBridge";
-import type { HostKeyInfo } from "../../components/terminal/TerminalHostKeyVerification";
+import type { HostKeyInfo } from "../../domain/hostKey";
 import {
   createKnownHostFromPortForwardHostKeyInfo,
   enqueuePortForwardHostKeyVerification,
@@ -9,7 +9,7 @@ import {
   toPendingPortForwardHostKeyVerification,
   type PendingPortForwardHostKeyVerification,
   type PortForwardHostKeyRequest,
-} from "../../components/port-forwarding/hostKeyVerification";
+} from "../../domain/portForwardHostKey";
 
 export interface PortForwardHostKeyVerificationState {
   hostKeyInfo: HostKeyInfo;

application/state/useServerStats.ts

@@ -0,0 +1,415 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+import { netcattyBridge } from '../../infrastructure/services/netcattyBridge';
+
+export interface DiskInfo {
+  capacityKey?: string;       // Filesystem or shared-pool identity for deduplication
+  mountPoint: string;
+  used: number;               // Used in GB
+  total: number;              // Total in GB
+  percent: number;            // Usage percentage
+}
+
+export interface NetInterfaceInfo {
+  name: string;               // Interface name (e.g., eth0, ens33)
+  rxBytes: number;            // Total received bytes
+  txBytes: number;            // Total transmitted bytes
+  rxSpeed: number;            // Receive speed (bytes/sec)
+  txSpeed: number;            // Transmit speed (bytes/sec)
+}
+
+export interface ProcessInfo {
+  pid: string;
+  memPercent: number;
+  command: string;
+}
+
+export interface ServerStats {
+  hostname?: string;            // Remote hostname
+  osName?: string;              // Remote operating system name
+  kernelRelease?: string;       // Remote kernel release
+  uptimeSeconds?: number | null;// Remote uptime in seconds
+  loadAverage?: number[];       // 1/5/15 minute load average
+  cpu: number | null;           // CPU usage percentage (0-100)
+  cpuCores: number | null;      // Number of CPU cores
+  cpuPerCore: number[];         // Per-core CPU usage array
+  memTotal: number | null;      // Total memory in MB
+  memUsed: number | null;       // Used memory in MB (excluding buffers/cache)
+  memFree: number | null;       // Free memory in MB
+  memBuffers: number | null;    // Buffers in MB
+  memCached: number | null;     // Cached in MB
+  swapTotal: number | null;     // Total swap in MB
+  swapUsed: number | null;      // Used swap in MB
+  topProcesses: ProcessInfo[];  // Top 10 processes by memory
+  diskPercent: number | null;   // Disk usage percentage for root partition
+  diskUsed: number | null;      // Disk used in GB
+  diskTotal: number | null;     // Total disk in GB
+  disks: DiskInfo[];            // All mounted disks
+  netRxSpeed: number;           // Total network receive speed (bytes/sec)
+  netTxSpeed: number;           // Total network transmit speed (bytes/sec)
+  latencyMs: number | null;     // TCP connection establishment latency to the SSH endpoint
+  netInterfaces: NetInterfaceInfo[];  // Per-interface network stats
+  lastUpdated: number | null;   // Timestamp of last successful update
+}
+
+interface UseServerStatsOptions {
+  sessionId: string;
+  enabled: boolean;           // Whether stats collection is enabled (from settings)
+  refreshInterval: number;    // Refresh interval in seconds
+  isSupportedOs: boolean;     // Only collect stats for Linux/macOS servers
+  isConnected: boolean;       // Only collect when connected
+}
+
+interface ServerStatsState {
+  stats: ServerStats;
+  isLoading: boolean;
+  error: string | null;
+}
+
+interface ServerStatsClient {
+  enabled: boolean;
+  refreshInterval: number;
+  isSupportedOs: boolean;
+  isConnected: boolean;
+}
+
+type ServerStatsListener = (state: ServerStatsState) => void;
+
+interface SharedServerStatsSession {
+  sessionId: string;
+  state: ServerStatsState;
+  listeners: Set<ServerStatsListener>;
+  clients: Map<number, ServerStatsClient>;
+  intervalRef: ReturnType<typeof setInterval> | null;
+  initialTimerRef: ReturnType<typeof setTimeout> | null;
+  connectedAt: number;
+  hasFetched: boolean;
+  fetchGeneration: number;
+  consecutiveFailures: number;
+  givenUp: boolean;
+  pollIntervalMs: number | null;
+  pollingActive: boolean;
+  inflight: Promise<void> | null;
+  inflightGeneration: number | null;
+}
+
+const CONSECUTIVE_FAILURE_LIMIT = 3;
+const serverStatsSessions = new Map<string, SharedServerStatsSession>();
+let nextClientId = 1;
+
+function createEmptyServerStats(): ServerStats {
+  return {
+    hostname: undefined,
+    osName: undefined,
+    kernelRelease: undefined,
+    uptimeSeconds: null,
+    loadAverage: [],
+    cpu: null,
+    cpuCores: null,
+    cpuPerCore: [],
+    memTotal: null,
+    memUsed: null,
+    memFree: null,
+    memBuffers: null,
+    memCached: null,
+    swapTotal: null,
+    swapUsed: null,
+    topProcesses: [],
+    diskPercent: null,
+    diskUsed: null,
+    diskTotal: null,
+    disks: [],
+    netRxSpeed: 0,
+    netTxSpeed: 0,
+    latencyMs: null,
+    netInterfaces: [],
+    lastUpdated: null,
+  };
+}
+
+function createInitialState(): ServerStatsState {
+  return {
+    stats: createEmptyServerStats(),
+    isLoading: false,
+    error: null,
+  };
+}
+
+function getSharedServerStatsSession(sessionId: string): SharedServerStatsSession {
+  const existing = serverStatsSessions.get(sessionId);
+  if (existing) return existing;
+
+  const session: SharedServerStatsSession = {
+    sessionId,
+    state: createInitialState(),
+    listeners: new Set(),
+    clients: new Map(),
+    intervalRef: null,
+    initialTimerRef: null,
+    connectedAt: 0,
+    hasFetched: false,
+    fetchGeneration: 0,
+    consecutiveFailures: 0,
+    givenUp: false,
+    pollIntervalMs: null,
+    pollingActive: false,
+    inflight: null,
+    inflightGeneration: null,
+  };
+  serverStatsSessions.set(sessionId, session);
+  return session;
+}
+
+function emitServerStatsState(session: SharedServerStatsSession): void {
+  for (const listener of session.listeners) {
+    listener(session.state);
+  }
+}
+
+function updateServerStatsState(session: SharedServerStatsSession, patch: Partial<ServerStatsState>): void {
+  session.state = { ...session.state, ...patch };
+  emitServerStatsState(session);
+}
+
+function clearServerStatsTimers(session: SharedServerStatsSession): void {
+  if (session.initialTimerRef) {
+    clearTimeout(session.initialTimerRef);
+    session.initialTimerRef = null;
+  }
+  if (session.intervalRef) {
+    clearInterval(session.intervalRef);
+    session.intervalRef = null;
+  }
+  session.pollingActive = false;
+  session.pollIntervalMs = null;
+}
+
+function resetServerStatsSession(session: SharedServerStatsSession): void {
+  clearServerStatsTimers(session);
+  session.connectedAt = 0;
+  session.hasFetched = false;
+  session.fetchGeneration += 1;
+  session.consecutiveFailures = 0;
+  session.givenUp = false;
+  updateServerStatsState(session, createInitialState());
+}
+
+function getActiveServerStatsClients(session: SharedServerStatsSession): ServerStatsClient[] {
+  return Array.from(session.clients.values()).filter((client) => (
+    client.enabled && client.isSupportedOs && client.isConnected
+  ));
+}
+
+function normalizeServerStats(stats: Partial<ServerStats>): ServerStats {
+  return {
+    hostname: stats.hostname,
+    osName: stats.osName,
+    kernelRelease: stats.kernelRelease,
+    uptimeSeconds: Number.isFinite(stats.uptimeSeconds) ? Number(stats.uptimeSeconds) : null,
+    loadAverage: Array.isArray(stats.loadAverage) ? stats.loadAverage : [],
+    cpu: stats.cpu ?? null,
+    cpuCores: stats.cpuCores ?? null,
+    cpuPerCore: stats.cpuPerCore || [],
+    memTotal: stats.memTotal ?? null,
+    memUsed: stats.memUsed ?? null,
+    memFree: stats.memFree ?? null,
+    memBuffers: stats.memBuffers ?? null,
+    memCached: stats.memCached ?? null,
+    swapTotal: stats.swapTotal ?? null,
+    swapUsed: stats.swapUsed ?? null,
+    topProcesses: stats.topProcesses || [],
+    diskPercent: stats.diskPercent ?? null,
+    diskUsed: stats.diskUsed ?? null,
+    diskTotal: stats.diskTotal ?? null,
+    disks: stats.disks || [],
+    netRxSpeed: stats.netRxSpeed || 0,
+    netTxSpeed: stats.netTxSpeed || 0,
+    latencyMs: Number.isFinite(stats.latencyMs) ? Number(stats.latencyMs) : null,
+    netInterfaces: stats.netInterfaces || [],
+    lastUpdated: Date.now(),
+  };
+}
+
+function markServerStatsFailure(session: SharedServerStatsSession, message: string): void {
+  session.consecutiveFailures += 1;
+  updateServerStatsState(session, { error: message });
+  if (session.consecutiveFailures >= CONSECUTIVE_FAILURE_LIMIT) {
+    // Stop polling this session. This covers network devices that advertise
+    // OpenSSH but do not support the POSIX stats shell command.
+    session.givenUp = true;
+    clearServerStatsTimers(session);
+  }
+}
+
+async function fetchSharedServerStats(session: SharedServerStatsSession, force = false): Promise<void> {
+  if (!session.sessionId) return;
+  if (session.inflight && session.inflightGeneration === session.fetchGeneration) {
+    await session.inflight;
+    return;
+  }
+  if (session.givenUp && !force) return;
+  if (getActiveServerStatsClients(session).length === 0) return;
+
+  const bridge = netcattyBridge.get();
+  if (!bridge?.getServerStats) return;
+
+  if (force) {
+    session.givenUp = false;
+    session.consecutiveFailures = 0;
+  }
+
+  const generation = session.fetchGeneration;
+  session.inflightGeneration = generation;
+  updateServerStatsState(session, { isLoading: true, error: null });
+
+  const request = (async () => {
+    try {
+      const result = await bridge.getServerStats(session.sessionId);
+
+      // Discard stale responses from before a polling restart or reconnect.
+      if (generation !== session.fetchGeneration) return;
+
+      if (result.pending) {
+        // Transient "not ready yet", e.g. a Mosh session whose SSH handshake
+        // has not finished. Do not count this toward the hard-failure cutoff.
+        return;
+      }
+
+      if (result.success && result.stats) {
+        session.hasFetched = true;
+        session.consecutiveFailures = 0;
+        updateServerStatsState(session, {
+          stats: normalizeServerStats(result.stats),
+          error: null,
+        });
+      } else if (result.error) {
+        markServerStatsFailure(session, result.error);
+      } else {
+        markServerStatsFailure(session, 'No stats returned');
+      }
+    } catch (err) {
+      if (generation === session.fetchGeneration) {
+        markServerStatsFailure(session, err instanceof Error ? err.message : 'Unknown error');
+      }
+    } finally {
+      if (generation === session.fetchGeneration) {
+        updateServerStatsState(session, { isLoading: false });
+      }
+    }
+  })();
+
+  session.inflight = request;
+  try {
+    await request;
+  } finally {
+    if (session.inflight === request) {
+      session.inflight = null;
+      session.inflightGeneration = null;
+    }
+  }
+}
+
+function reconcileSharedServerStatsSession(session: SharedServerStatsSession): void {
+  const activeClients = getActiveServerStatsClients(session);
+
+  if (activeClients.length === 0) {
+    resetServerStatsSession(session);
+    return;
+  }
+
+  if (session.connectedAt === 0) {
+    session.connectedAt = Date.now();
+  }
+
+  const intervalMs = Math.max(5, Math.min(...activeClients.map((client) => client.refreshInterval))) * 1000;
+  const shouldRestartPolling = !session.pollingActive || session.pollIntervalMs !== intervalMs;
+  if (!shouldRestartPolling) return;
+  if (session.givenUp) return;
+
+  clearServerStatsTimers(session);
+  session.fetchGeneration += 1;
+  session.pollingActive = true;
+  session.pollIntervalMs = intervalMs;
+
+  const connectionAge = Date.now() - session.connectedAt;
+  const needsWarmup = !session.hasFetched && connectionAge < 2000;
+
+  session.initialTimerRef = setTimeout(() => {
+    session.initialTimerRef = null;
+    void fetchSharedServerStats(session);
+  }, needsWarmup ? 2000 : 0);
+  session.intervalRef = setInterval(() => {
+    void fetchSharedServerStats(session);
+  }, intervalMs);
+}
+
+function maybeDisposeSharedServerStatsSession(session: SharedServerStatsSession): void {
+  if (session.clients.size > 0 || session.listeners.size > 0) return;
+  clearServerStatsTimers(session);
+  session.fetchGeneration += 1;
+  serverStatsSessions.delete(session.sessionId);
+}
+
+export function useServerStats({
+  sessionId,
+  enabled,
+  refreshInterval,
+  isSupportedOs,
+  isConnected,
+}: UseServerStatsOptions) {
+  const clientIdRef = useRef<number | null>(null);
+  if (clientIdRef.current === null) {
+    clientIdRef.current = nextClientId;
+    nextClientId += 1;
+  }
+
+  const [state, setState] = useState<ServerStatsState>(() => getSharedServerStatsSession(sessionId).state);
+
+  useEffect(() => {
+    const session = getSharedServerStatsSession(sessionId);
+    const clientId = clientIdRef.current;
+    if (clientId === null) return;
+
+    const listener: ServerStatsListener = (nextState) => {
+      setState(nextState);
+    };
+
+    session.listeners.add(listener);
+    setState(session.state);
+
+    return () => {
+      session.listeners.delete(listener);
+      session.clients.delete(clientId);
+      reconcileSharedServerStatsSession(session);
+      maybeDisposeSharedServerStatsSession(session);
+    };
+  }, [sessionId]);
+
+  useEffect(() => {
+    const session = getSharedServerStatsSession(sessionId);
+    const clientId = clientIdRef.current;
+    if (clientId === null) return;
+
+    session.clients.set(clientId, {
+      enabled,
+      refreshInterval,
+      isSupportedOs,
+      isConnected,
+    });
+    setState(session.state);
+    reconcileSharedServerStatsSession(session);
+  }, [sessionId, enabled, refreshInterval, isSupportedOs, isConnected]);
+
+  const refresh = useCallback(() => {
+    const session = getSharedServerStatsSession(sessionId);
+    void fetchSharedServerStats(session, true).finally(() => {
+      reconcileSharedServerStatsSession(session);
+    });
+  }, [sessionId]);
+
+  return {
+    stats: state.stats,
+    isLoading: state.isLoading,
+    error: state.error,
+    refresh,
+  };
+}

application/state/useSessionState.ts

@@ -542,6 +542,7 @@ export const useSessionState = ({
       workspaces: workspacesRef.current,
       sessionIds,
       currentActiveTabId: activeTabStore.getActiveTabId(),
+      preferredTabId: activeTabStore.getPreviousActiveTabId(),
       tabOrder: tabOrderRef.current,
     });
 
@@ -549,9 +550,10 @@ export const useSessionState = ({
     setSessions(result.sessions);
     setTabOrder(result.tabOrder);
     if (result.activeTabId) {
-      setActiveTabId(result.activeTabId);
+      // Closing must not rewrite previous-tab history to the closed tab.
+      activeTabStore.setActiveTabId(result.activeTabId, { recordPrevious: false });
     }
-  }, [setActiveTabId]);
+  }, []);
 
   const closeSession = useCallback((sessionId: string, e?: MouseEvent) => {
     e?.stopPropagation();
@@ -619,17 +621,26 @@ export const useSessionState = ({
     });
   }, []);
 
-  const submitWorkspaceRename = useCallback(() => {
+  const submitWorkspaceRename = useCallback((workspaceId?: string, name?: string) => {
+    if (workspaceId !== undefined && name !== undefined) {
+      const trimmed = name.trim();
+      if (!trimmed) return;
+      setWorkspaces(prev => prev.map(w => (
+        w.id === workspaceId ? { ...w, title: trimmed, autoTitle: false } : w
+      )));
+      return;
+    }
+
     setWorkspaceRenameValue(prevValue => {
-      const name = prevValue.trim();
-      if (!name) return prevValue;
-      
+      const trimmed = prevValue.trim();
+      if (!trimmed) return prevValue;
+
       setWorkspaceRenameTarget(prevTarget => {
         if (!prevTarget) return prevTarget;
-        setWorkspaces(prev => prev.map(w => w.id === prevTarget.id ? { ...w, title: name, autoTitle: false } : w));
+        setWorkspaces(prev => prev.map(w => w.id === prevTarget.id ? { ...w, title: trimmed, autoTitle: false } : w));
         return null;
       });
-      
+
       return '';
     });
   }, []);

application/state/useSettingsState.ts

@@ -1,6 +1,15 @@
 import { useCallback, useEffect, useLayoutEffect, useMemo, useRef, useState, type SetStateAction } from 'react';
 
 import { runThemeTransition, type ThemeTransitionMode } from './themeTransition';
+import { publishAppearanceChromeSnapshot } from './appearanceChromeStore';
+import {
+  publishSettingsChromeSnapshot,
+  registerSettingsChromeActions,
+} from './settingsChromeStore';
+import {
+  publishTerminalSettingsSnapshot,
+  registerTerminalSettingsActions,
+} from './terminalSettingsStore';
 import { SyncConfig, TerminalSettings, HotkeyScheme, CustomKeyBindings, DEFAULT_KEY_BINDINGS, KeyBinding, UILanguage, SessionLogFormat, normalizeTerminalSettings } from '../../domain/models';
 import {
   DEFAULT_HTTP_NETWORK_PROXY,
@@ -35,6 +44,7 @@ import {
   STORAGE_KEY_SFTP_AUTO_OPEN_SIDEBAR,
   STORAGE_KEY_SFTP_FOLLOW_TERMINAL_CWD,
   STORAGE_KEY_SFTP_TRANSFER_CONCURRENCY,
+  STORAGE_KEY_SFTP_SKIP_UNCHANGED,
   STORAGE_KEY_SSH_TRANSPORT_IDLE_TTL_MS,
   STORAGE_KEY_SFTP_TRANSFER_POOL_IDLE_TTL_MS,
   STORAGE_KEY_SFTP_DEFAULT_VIEW_MODE,
@@ -84,7 +94,10 @@ import { DEFAULT_UI_FONT_ID, withWindowsEmojiFallback } from '../../infrastructu
 import { uiFontStore, useUIFontsLoaded } from './uiFontStore';
 import { localStorageAdapter } from '../../infrastructure/persistence/localStorageAdapter';
 import { netcattyBridge } from '../../infrastructure/services/netcattyBridge';
-import { resolveSftpTransferConcurrency } from './sftp/transferConcurrency';
+import {
+  resolveSftpTransferConcurrency,
+  resolveSftpSkipUnchangedEnabled,
+} from './sftp/transferConcurrency';
 import { resolveSshTransportIdleTtlMs } from '../../infrastructure/config/sshTransportIdleTtl';
 import {
   DEFAULT_ACCENT_MODE,
@@ -420,6 +433,9 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
   // Folder transfer concurrency is renderer-only (runSftpTransferWorkers).
   // Do not push it into main-process host admission - that made multi-select
   // top-level files queue against each other and against folder children.
+  const [sftpSkipUnchanged, setSftpSkipUnchanged] = useState<boolean>(() =>
+    resolveSftpSkipUnchangedEnabled(() => localStorageAdapter.readBoolean(STORAGE_KEY_SFTP_SKIP_UNCHANGED)),
+  );
 
   const [sshTransportIdleTtlMs, setSshTransportIdleTtlMsState] = useState<number>(() => {
     // Prefer the new SSH transport key; if absent (upgrade), migrate the legacy
@@ -740,7 +756,10 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
 
   // Push idle TTL to the main-process transport registry on load and whenever
   // it changes (including cross-window IPC/storage updates to local state).
+  const lastPushedSshTransportIdleTtlRef = useRef<number | null>(null);
   useEffect(() => {
+    if (lastPushedSshTransportIdleTtlRef.current === sshTransportIdleTtlMs) return;
+    lastPushedSshTransportIdleTtlRef.current = sshTransportIdleTtlMs;
     notifySettingsChanged(STORAGE_KEY_SSH_TRANSPORT_IDLE_TTL_MS, sshTransportIdleTtlMs);
   }, [sshTransportIdleTtlMs, notifySettingsChanged]);
 
@@ -890,6 +909,8 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     if (storedHidden === 'true' || storedHidden === 'false') setSftpShowHiddenFiles(storedHidden === 'true');
     const storedCompress = readStoredString(STORAGE_KEY_SFTP_USE_COMPRESSED_UPLOAD);
     if (storedCompress === 'true' || storedCompress === 'false') setSftpUseCompressedUpload(storedCompress === 'true');
+    const storedSkipUnchanged = localStorageAdapter.readBoolean(STORAGE_KEY_SFTP_SKIP_UNCHANGED);
+    if (storedSkipUnchanged != null) setSftpSkipUnchanged(storedSkipUnchanged);
     const storedAutoOpenSidebar = readStoredString(STORAGE_KEY_SFTP_AUTO_OPEN_SIDEBAR);
     if (storedAutoOpenSidebar === 'true' || storedAutoOpenSidebar === 'false') setSftpAutoOpenSidebar(storedAutoOpenSidebar === 'true');
     const storedFollowTerminalCwd = readStoredString(STORAGE_KEY_SFTP_FOLLOW_TERMINAL_CWD);
@@ -958,6 +979,8 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     const persistedAppearanceChanged = previousAppearance === null
       || hasPersistedAppearanceChanged(previousAppearance, appearanceRender);
     previousAppearanceRenderRef.current = appearanceRender;
+    // Terminal leaves subscribe here so accent drag does not rebuild TerminalLayer.
+    publishAppearanceChromeSnapshot({ accentMode, customAccent });
     const tokens = getUiThemeById(resolvedTheme, resolvedTheme === 'dark' ? darkUiThemeId : lightUiThemeId).tokens;
     const apply = () => applyThemeTokens(theme, resolvedTheme, tokens, accentMode, customAccent);
     const transitionMode = appearanceTransitionModeRef.current;
@@ -1121,7 +1144,7 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     customCSS, uiFontFamilyId, hotkeyScheme, uiLanguage,
     terminalThemeId, followAppTerminalTheme, terminalFontFamilyId, terminalFontSize,
     sftpDoubleClickBehavior, sftpAutoSync, sftpShowHiddenFiles,
-    sftpUseCompressedUpload, sftpAutoOpenSidebar, sftpFollowTerminalCwd, sftpDefaultViewMode,
+    sftpUseCompressedUpload, sftpSkipUnchanged, sftpAutoOpenSidebar, sftpFollowTerminalCwd, sftpDefaultViewMode,
     showRecentHosts, hostClickBehavior, showOnlyUngroupedHostsInRoot, showSftpTab, showHostTreeSidebar, terminalSidePanelAutoOpen, terminalSidePanelAutoOpenTab, shellOnlyTabNumberShortcuts, disableTerminalFontZoom, restorePreviousSession, restoreTerminalCwd,
     editorWordWrap, sessionLogsEnabled, sessionLogsDir, sessionLogsFormat, sessionLogsTimestampsEnabled, sshDebugLogsEnabled, sshDeepLinkEnabled, jmsDeepLinkEnabled, explorerContextMenuEnabled,
     globalHotkeyEnabled, autoUpdateEnabled, windowOpacity, appIconVariant,
@@ -1131,7 +1154,7 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     setTerminalThemeId, setTerminalThemeDarkId, setTerminalThemeLightId,
     setFollowAppTerminalThemeState, setTerminalFontFamilyId, setTerminalFontSize: applyIncomingTerminalFontSize,
     setSftpDoubleClickBehavior, setSftpAutoSync, setSftpShowHiddenFiles,
-    setSftpUseCompressedUpload, setSftpAutoOpenSidebar, setSftpFollowTerminalCwd, setSftpDefaultViewMode,
+    setSftpUseCompressedUpload, setSftpSkipUnchanged, setSftpAutoOpenSidebar, setSftpFollowTerminalCwd, setSftpDefaultViewMode,
     setShowRecentHostsState, setHostClickBehaviorState, setShowOnlyUngroupedHostsInRootState, setShowSftpTabState, setShowHostTreeSidebarState, setTerminalSidePanelAutoOpenState, setTerminalSidePanelAutoOpenTabState, setShellOnlyTabNumberShortcutsState, setDisableTerminalFontZoomState, setRestorePreviousSessionState, setRestoreTerminalCwdState,
     setEditorWordWrapState, setSessionLogsEnabled, setSessionLogsDir, setSessionLogsFormat, setSessionLogsTimestampsEnabled, setSshDebugLogsEnabled, setSshDeepLinkEnabledState: applyIncomingSshDeepLinkEnabled, setJmsDeepLinkEnabledState: applyIncomingJmsDeepLinkEnabled, setExplorerContextMenuEnabledState: applyIncomingExplorerContextMenuEnabled,
     setGlobalHotkeyEnabled, setWindowOpacity: applyIncomingWindowOpacity, setAppIconVariant, setAutoUpdateEnabled, setWorkspaceFocusStyleState,
@@ -1359,6 +1382,12 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     notifySettingsChanged(STORAGE_KEY_SFTP_USE_COMPRESSED_UPLOAD, sftpUseCompressedUpload);
   }, [sftpUseCompressedUpload, notifySettingsChanged]);
 
+  useEffect(() => {
+    localStorageAdapter.writeBoolean(STORAGE_KEY_SFTP_SKIP_UNCHANGED, sftpSkipUnchanged);
+    if (!persistMountedRef.current) return;
+    notifySettingsChanged(STORAGE_KEY_SFTP_SKIP_UNCHANGED, sftpSkipUnchanged);
+  }, [sftpSkipUnchanged, notifySettingsChanged]);
+
   // Persist SFTP auto-open sidebar setting
   useEffect(() => {
     localStorageAdapter.writeString(STORAGE_KEY_SFTP_AUTO_OPEN_SIDEBAR, sftpAutoOpenSidebar ? 'true' : 'false');
@@ -1616,11 +1645,13 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     notifySettingsChanged,
   });
 
-  // Fix 1: Mark all persist effects as mounted.
-  // This MUST be declared AFTER all persist useEffects so that React runs it last
-  // during the initial mount cycle (effects fire in declaration order).
+  // Mark persist effects mounted AFTER all persist useEffects so React runs
+  // this last (declaration order). Cleanup clears the latch for remount.
   useEffect(() => {
     persistMountedRef.current = true;
+    return () => {
+      persistMountedRef.current = false;
+    };
   }, []);
 
   // Get merged key bindings (defaults + custom overrides)
@@ -1691,6 +1722,142 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     applyThemeTokens(theme, resolvedTheme, tokens, accentMode, customAccent);
   }, [theme, resolvedTheme, lightUiThemeId, darkUiThemeId, accentMode, customAccent]);
 
+  const setEditorWordWrap = useCallback((enabled: boolean) => {
+    setEditorWordWrapState(enabled);
+    localStorageAdapter.writeString(STORAGE_KEY_EDITOR_WORD_WRAP, String(enabled));
+    notifySettingsChanged(STORAGE_KEY_EDITOR_WORD_WRAP, enabled);
+  }, [notifySettingsChanged]);
+
+  // Main-window chrome subscribes to this slice instead of receiving the whole
+  // settings object through the App domain bags. The store dedupes field by
+  // field, so unrelated settings churn never notifies chrome consumers.
+  useLayoutEffect(() => {
+    publishSettingsChromeSnapshot({
+      theme,
+      resolvedTheme,
+      lightUiThemeId,
+      darkUiThemeId,
+      uiLanguage,
+      windowOpacity,
+      showSftpTab,
+      showHostTreeSidebar,
+      showRecentHosts,
+      hostClickBehavior,
+      showOnlyUngroupedHostsInRoot,
+      dynamicTabTitleMode: terminalSettings.dynamicTabTitleMode,
+      disableTerminalFontZoom,
+      restoreTerminalCwd,
+      terminalSidePanelAutoOpen,
+      terminalSidePanelAutoOpenTab,
+    });
+  }, [
+    darkUiThemeId,
+    disableTerminalFontZoom,
+    hostClickBehavior,
+    lightUiThemeId,
+    resolvedTheme,
+    restoreTerminalCwd,
+    showHostTreeSidebar,
+    showOnlyUngroupedHostsInRoot,
+    showRecentHosts,
+    showSftpTab,
+    terminalSettings.dynamicTabTitleMode,
+    terminalSidePanelAutoOpen,
+    terminalSidePanelAutoOpenTab,
+    theme,
+    uiLanguage,
+    windowOpacity,
+  ]);
+
+  useLayoutEffect(() => {
+    registerSettingsChromeActions({ setTheme, setWindowOpacity });
+    return () => {
+      registerSettingsChromeActions(null);
+    };
+  }, [setTheme, setWindowOpacity]);
+
+  // TerminalHost / terminal domain bags subscribe here instead of receiving
+  // settings through the App mega-subscriber.
+  useLayoutEffect(() => {
+    publishTerminalSettingsSnapshot({
+      terminalThemeId,
+      terminalThemeDarkId,
+      terminalThemeLightId,
+      followAppTerminalTheme,
+      terminalFontFamilyId,
+      terminalFontSize,
+      terminalSettings,
+      hotkeyScheme,
+      keyBindings,
+      isHotkeyRecording,
+      sftpDoubleClickBehavior,
+      sftpAutoSync,
+      sftpShowHiddenFiles,
+      sftpUseCompressedUpload,
+      sftpAutoOpenSidebar,
+      sftpFollowTerminalCwd,
+      sftpDefaultViewMode,
+      editorWordWrap,
+      sessionLogsEnabled,
+      sessionLogsDir,
+      sessionLogsFormat,
+      sessionLogsTimestampsEnabled,
+      sshDebugLogsEnabled,
+    });
+  }, [
+    editorWordWrap,
+    followAppTerminalTheme,
+    hotkeyScheme,
+    isHotkeyRecording,
+    keyBindings,
+    sessionLogsDir,
+    sessionLogsEnabled,
+    sessionLogsFormat,
+    sessionLogsTimestampsEnabled,
+    sftpAutoOpenSidebar,
+    sftpAutoSync,
+    sftpDefaultViewMode,
+    sftpDoubleClickBehavior,
+    sftpFollowTerminalCwd,
+    sftpShowHiddenFiles,
+    sftpUseCompressedUpload,
+    sshDebugLogsEnabled,
+    terminalFontFamilyId,
+    terminalFontSize,
+    terminalSettings,
+    terminalThemeDarkId,
+    terminalThemeId,
+    terminalThemeLightId,
+  ]);
+
+  useLayoutEffect(() => {
+    registerTerminalSettingsActions({
+      setTerminalThemeId,
+      setTerminalThemeDarkId,
+      setTerminalThemeLightId,
+      setFollowAppTerminalTheme: setFollowAppTerminalThemeState,
+      setTerminalFontFamilyId,
+      setTerminalFontSize,
+      updateTerminalSetting,
+      setSftpFollowTerminalCwd,
+      setEditorWordWrap,
+      applyAppTheme,
+    });
+    return () => {
+      registerTerminalSettingsActions(null);
+    };
+  }, [
+    applyAppTheme,
+    setEditorWordWrap,
+    setSftpFollowTerminalCwd,
+    setTerminalFontFamilyId,
+    setTerminalFontSize,
+    setTerminalThemeDarkId,
+    setTerminalThemeId,
+    setTerminalThemeLightId,
+    updateTerminalSetting,
+  ]);
+
   return {
     theme,
     setTheme,
@@ -1744,6 +1911,8 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     setSftpShowHiddenFiles,
     sftpUseCompressedUpload,
     setSftpUseCompressedUpload,
+    sftpSkipUnchanged,
+    setSftpSkipUnchanged,
     sftpAutoOpenSidebar,
     setSftpAutoOpenSidebar,
     sftpFollowTerminalCwd,
@@ -1778,11 +1947,7 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     setSshTransportIdleTtlMs,
     // Editor Settings
     editorWordWrap,
-    setEditorWordWrap: useCallback((enabled: boolean) => {
-      setEditorWordWrapState(enabled);
-      localStorageAdapter.writeString(STORAGE_KEY_EDITOR_WORD_WRAP, String(enabled));
-      notifySettingsChanged(STORAGE_KEY_EDITOR_WORD_WRAP, enabled);
-    }, [notifySettingsChanged]),
+    setEditorWordWrap,
     // Session Logs
     sessionLogsEnabled,
     setSessionLogsEnabled,
@@ -1824,11 +1989,11 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     // Opaque version that changes when any synced setting changes, used by useAutoSync.
     // eslint-disable-next-line react-hooks/exhaustive-deps
     settingsVersion: useMemo(() => Math.random(), [
-      theme, lightUiThemeId, darkUiThemeId, accentMode, customAccent,
+      theme, lightUiThemeId, darkUiThemeId, accentMode,
       uiFontFamilyId, uiLanguage, customCSS,
       terminalThemeId, terminalFontFamilyId, terminalFontSize, terminalSettings,
       customKeyBindings, editorWordWrap,
-      sftpDoubleClickBehavior, sftpAutoSync, sftpShowHiddenFiles, sftpUseCompressedUpload, sftpAutoOpenSidebar, sftpFollowTerminalCwd, sftpDefaultViewMode,
+      sftpDoubleClickBehavior, sftpAutoSync, sftpShowHiddenFiles, sftpUseCompressedUpload, sftpSkipUnchanged, sftpAutoOpenSidebar, sftpFollowTerminalCwd, sftpDefaultViewMode,
       showRecentHosts, hostClickBehavior, showOnlyUngroupedHostsInRoot, showSftpTab, showHostTreeSidebar, terminalSidePanelAutoOpen, terminalSidePanelAutoOpenTab, shellOnlyTabNumberShortcuts, disableTerminalFontZoom,
       customThemes, workspaceFocusStyle, sessionLogsTimestampsEnabled, sshDebugLogsEnabled, sshDeepLinkEnabled, jmsDeepLinkEnabled, explorerContextMenuEnabled,
     ]),

application/state/useSftpState.ts

@@ -399,14 +399,6 @@ export const useSftpState = (
     [hosts, identities, keys, openPoolSftpSession, transferKnownHosts, transferPoolKeyCache, transferTerminalSettings],
   );
 
-  /**
-   * @deprecated No-op. SSH transport idle park keeps connections warm; opening
-   * a background transfer channel is unnecessary and could re-trigger MFA.
-   */
-  const warmTransferPoolForHost = useCallback(async (_hostId: string) => {
-    // Intentionally empty — unified transport registry owns keep-alive.
-  }, []);
-
   /** True after browse channels were soft-closed while this owner stayed mounted. */
   const browseParkedRef = useRef(false);
   const browseLifecycleGenRef = useRef(0);
@@ -824,7 +816,6 @@ export const useSftpState = (
     rejectHostKeyVerification,
     acceptHostKeyVerification,
     acceptAndSaveHostKeyVerification,
-    warmTransferPoolForHost,
   };
   const methodsRef = useRef(currentMethods);
   methodsRef.current = currentMethods;
@@ -907,8 +898,6 @@ export const useSftpState = (
     rejectHostKeyVerification: () => methodsRef.current.rejectHostKeyVerification(),
     acceptHostKeyVerification: () => methodsRef.current.acceptHostKeyVerification(),
     acceptAndSaveHostKeyVerification: () => methodsRef.current.acceptAndSaveHostKeyVerification(),
-    warmTransferPoolForHost: (...args: Parameters<typeof warmTransferPoolForHost>) =>
-      methodsRef.current.warmTransferPoolForHost(...args),
     activeFileWatchCountRef,
   }), [activeFileWatchCountRef]); // activeFileWatchCountRef is a stable ref
 

application/state/useSystemManager.ts

@@ -0,0 +1,326 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+import { useI18n } from '../i18n/I18nProvider';
+import type { I18nContextValue } from '../i18n/I18nProvider';
+import { sessionCapabilitiesStore } from './sessionCapabilitiesStore';
+import type { SessionCapabilities } from '../../domain/systemManager/types';
+import type { useSystemManagerBackend } from './useSystemManagerBackend';
+import { nextPollData } from '../../domain/systemManager/pollListStable';
+
+type Backend = ReturnType<typeof useSystemManagerBackend>;
+
+function delay(ms: number): Promise<void> {
+  return new Promise((resolve) => window.setTimeout(resolve, ms));
+}
+
+function normalizePollingErrorMessage(error: unknown, t: I18nContextValue['t']): string {
+  const message = error instanceof Error ? error.message : String(error || 'Unknown error');
+  const lower = message.toLowerCase();
+  if (lower.includes('channel open failure') || lower.includes('unable to exec')) {
+    return t('systemManager.errors.sshChannelUnavailable');
+  }
+  return message;
+}
+
+/** Stable i18n ref so polling fetchers do not reset when locale re-renders. */
+export function useStableTranslate(): I18nContextValue['t'] {
+  const { t } = useI18n();
+  const tRef = useRef(t);
+  tRef.current = t;
+  return useCallback(
+    (key, values) => tRef.current(key, values),
+    [],
+  );
+}
+
+export function useSessionCapabilities(
+  sessionId: string | null,
+  isConnected: boolean,
+  backend: Backend,
+  enabled: boolean,
+  capabilitiesTtlMs: number,
+) {
+  const ttlMsRef = useRef(capabilitiesTtlMs);
+  ttlMsRef.current = capabilitiesTtlMs;
+
+  const [capabilities, setCapabilities] = useState<SessionCapabilities | undefined>(
+    () => (sessionId ? sessionCapabilitiesStore.get(sessionId) : undefined),
+  );
+  const [probing, setProbing] = useState(false);
+
+  useEffect(() => {
+    if (!sessionId) return undefined;
+    return sessionCapabilitiesStore.subscribe(sessionId, () => {
+      setCapabilities(sessionCapabilitiesStore.get(sessionId));
+    });
+  }, [sessionId]);
+
+  useEffect(() => {
+    if (!sessionId || isConnected) return undefined;
+    sessionCapabilitiesStore.delete(sessionId);
+    return undefined;
+  }, [sessionId, isConnected]);
+
+  const probe = useCallback(async (force = false) => {
+    if (!sessionId || !isConnected) return;
+    if (!force && sessionCapabilitiesStore.get(sessionId)) return;
+    setProbing(true);
+    try {
+      const result = await backend.probeSystemCapabilities(sessionId);
+      if (result.success && result.capabilities) {
+        sessionCapabilitiesStore.set(sessionId, result.capabilities, ttlMsRef.current);
+      }
+    } finally {
+      setProbing(false);
+    }
+  }, [backend, isConnected, sessionId]);
+
+  useEffect(() => {
+    if (!sessionId || !isConnected || !enabled) return undefined;
+    void probe();
+    return undefined;
+  }, [enabled, sessionId, isConnected, probe]);
+
+  return { capabilities, probing, refreshCapabilities: () => probe(true) };
+}
+
+/** Prefetch capabilities only for the given session ids (e.g. when System panel opens). */
+export function useSystemCapabilitiesWarmup(
+  sessionIds: string[],
+  backend: Backend,
+  enabled: boolean,
+  capabilitiesTtlMs: number,
+) {
+  const backendRef = useRef(backend);
+  backendRef.current = backend;
+  const inflightRef = useRef(new Set<string>());
+  const ttlMsRef = useRef(capabilitiesTtlMs);
+  ttlMsRef.current = capabilitiesTtlMs;
+
+  const sessionKey = enabled ? sessionIds.slice().sort().join(',') : '';
+
+  useEffect(() => {
+    if (!sessionKey) return undefined;
+    for (const sessionId of sessionKey.split(',')) {
+      if (!sessionId || sessionCapabilitiesStore.get(sessionId)) continue;
+      if (inflightRef.current.has(sessionId)) continue;
+      inflightRef.current.add(sessionId);
+      void backendRef.current.probeSystemCapabilities(sessionId).then((result) => {
+        inflightRef.current.delete(sessionId);
+        if (result.success && result.capabilities) {
+          sessionCapabilitiesStore.set(sessionId, result.capabilities, ttlMsRef.current);
+        }
+      });
+    }
+    return undefined;
+  }, [sessionKey]);
+}
+
+export function usePolling<T>(
+  fetcher: () => Promise<T | null>,
+  intervalMs: number,
+  enabled: boolean,
+  merge?: (prev: T | null, next: T) => T,
+  options?: { poll?: boolean; resetKey?: string },
+) {
+  const stableT = useStableTranslate();
+  const resetKey = options?.resetKey ?? '';
+  const [data, setData] = useState<T | null>(null);
+  const [dataKey, setDataKey] = useState(resetKey);
+  const [error, setError] = useState<string | null>(null);
+  const [errorKey, setErrorKey] = useState(resetKey);
+  const [loading, setLoading] = useState(false);
+  const [loadingKey, setLoadingKey] = useState(resetKey);
+  const failuresRef = useRef(0);
+  const hasDataRef = useRef(false);
+  const enabledRef = useRef(enabled);
+  const generationRef = useRef(0);
+  const runIdRef = useRef(0);
+  const loadingRunIdRef = useRef(0);
+  const inflightRef = useRef<{ generation: number; runId: number } | null>(null);
+  const queuedRunRef = useRef<{
+    options?: { withLoading?: boolean; minLoadingMs?: number };
+    resolve: () => void;
+  } | null>(null);
+  const fetcherRef = useRef(fetcher);
+  const mergeRef = useRef(merge);
+  const pollRef = useRef(options?.poll ?? true);
+  const resetKeyRef = useRef(resetKey);
+  const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  enabledRef.current = enabled;
+  fetcherRef.current = fetcher;
+  mergeRef.current = merge;
+  pollRef.current = options?.poll ?? true;
+
+  const clearPollTimer = useCallback(() => {
+    if (timerRef.current !== null) {
+      clearTimeout(timerRef.current);
+      timerRef.current = null;
+    }
+  }, []);
+
+  const pollDelayMs = useCallback(() => {
+    if (failuresRef.current >= 3) return intervalMs * 4;
+    return intervalMs;
+  }, [intervalMs]);
+
+  const resolveQueuedRun = useCallback(() => {
+    queuedRunRef.current?.resolve();
+    queuedRunRef.current = null;
+  }, []);
+
+  const run = useCallback(async (options?: { withLoading?: boolean; minLoadingMs?: number }) => {
+    const generation = generationRef.current;
+    const runResetKey = resetKeyRef.current;
+    if (!enabledRef.current) return;
+    if (inflightRef.current?.generation === generation) {
+      if (options?.withLoading) {
+        queuedRunRef.current?.resolve();
+        loadingRunIdRef.current = 0;
+        setLoadingKey(runResetKey);
+        setLoading(true);
+        return new Promise<void>((resolve) => {
+          queuedRunRef.current = { options, resolve };
+        });
+      }
+      return;
+    }
+    const runId = ++runIdRef.current;
+    inflightRef.current = { generation, runId };
+    const showLoading = options?.withLoading ?? !hasDataRef.current;
+    const startedAt = Date.now();
+    const isCurrent = () => (
+      generationRef.current === generation
+      && enabledRef.current
+      && inflightRef.current?.runId === runId
+      && resetKeyRef.current === runResetKey
+    );
+    if (showLoading) {
+      loadingRunIdRef.current = runId;
+      setLoadingKey(runResetKey);
+      setLoading(true);
+    }
+    try {
+      const result = await fetcherRef.current();
+      if (!isCurrent()) return;
+      if (result !== null) {
+        setDataKey(runResetKey);
+        setData((prev) => {
+          const mergeFn = mergeRef.current;
+          const next = mergeFn ? mergeFn(prev, result) : nextPollData(prev, result);
+          if (next !== prev) hasDataRef.current = true;
+          return next;
+        });
+        setErrorKey(runResetKey);
+        setError(null);
+        failuresRef.current = 0;
+      }
+    } catch (err) {
+      if (!isCurrent()) return;
+      failuresRef.current += 1;
+      setDataKey(runResetKey);
+      setData(null);
+      hasDataRef.current = false;
+      setErrorKey(runResetKey);
+      setError(normalizePollingErrorMessage(err, stableT));
+    } finally {
+      if (inflightRef.current?.runId === runId) {
+        inflightRef.current = null;
+      }
+      if (showLoading) {
+        const remaining = Math.max(0, (options?.minLoadingMs ?? 0) - (Date.now() - startedAt));
+        if (remaining > 0) await delay(remaining);
+        if (
+          generationRef.current === generation
+          && enabledRef.current
+          && resetKeyRef.current === runResetKey
+          && loadingRunIdRef.current === runId
+        ) {
+          loadingRunIdRef.current = 0;
+          setLoadingKey(runResetKey);
+          setLoading(false);
+        }
+      }
+      const queued = queuedRunRef.current;
+      if (
+        queued
+        && generationRef.current === generation
+        && enabledRef.current
+        && resetKeyRef.current === runResetKey
+      ) {
+        queuedRunRef.current = null;
+        await run(queued.options);
+        queued.resolve();
+      }
+    }
+  }, [stableT]);
+
+  const scheduleNextPoll = useCallback(() => {
+    clearPollTimer();
+    if (!enabledRef.current || !pollRef.current) return;
+    const generation = generationRef.current;
+    timerRef.current = setTimeout(() => {
+      void run({ withLoading: false }).finally(() => {
+        if (generationRef.current === generation) {
+          scheduleNextPoll();
+        }
+      });
+    }, pollDelayMs());
+  }, [clearPollTimer, pollDelayMs, run]);
+
+  useEffect(() => {
+    const resetChanged = resetKeyRef.current !== resetKey;
+    resetKeyRef.current = resetKey;
+    generationRef.current += 1;
+    inflightRef.current = null;
+    clearPollTimer();
+    if (!enabled) {
+      resolveQueuedRun();
+      loadingRunIdRef.current = 0;
+      setLoading(false);
+      setLoadingKey(resetKey);
+      setDataKey(resetKey);
+      setData(null);
+      setErrorKey(resetKey);
+      setError(null);
+      failuresRef.current = 0;
+      hasDataRef.current = false;
+      return undefined;
+    }
+    if (resetChanged) {
+      resolveQueuedRun();
+      loadingRunIdRef.current = 0;
+      setLoading(false);
+      setLoadingKey(resetKey);
+      setDataKey(resetKey);
+      setData(null);
+      setErrorKey(resetKey);
+      setError(null);
+      failuresRef.current = 0;
+      hasDataRef.current = false;
+    }
+    const generation = generationRef.current;
+    void run({ withLoading: true }).finally(() => {
+      if (generationRef.current === generation && pollRef.current) scheduleNextPoll();
+    });
+    return () => {
+      generationRef.current += 1;
+      resolveQueuedRun();
+      loadingRunIdRef.current = 0;
+      inflightRef.current = null;
+      clearPollTimer();
+    };
+  }, [clearPollTimer, enabled, intervalMs, options?.poll, resetKey, resolveQueuedRun, run, scheduleNextPoll]);
+
+  const refresh = useCallback(async () => {
+    failuresRef.current = 0;
+    await run({ withLoading: true, minLoadingMs: 450 });
+  }, [run]);
+
+  return {
+    data: dataKey === resetKey ? data : null,
+    error: errorKey === resetKey ? error : null,
+    loading: loadingKey === resetKey ? loading : enabled,
+    refresh,
+  };
+}

application/state/useTerminalAiContexts.architecture.test.ts

@@ -0,0 +1,10 @@
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import test from "node:test";
+
+const source = readFileSync(new URL("./useTerminalAiContexts.ts", import.meta.url), "utf8");
+
+test("useTerminalAiContexts imports AI context primitives from domain", () => {
+  assert.match(source, /from ['"]\.\.\/\.\.\/domain\/buildAITerminalSessionInfo['"]/);
+  assert.doesNotMatch(source, /from ['"].*components\//);
+});

application/state/useTerminalAiContexts.ts

@@ -0,0 +1,146 @@
+import type React from 'react';
+import { useCallback, useMemo, useRef } from 'react';
+
+import { retainStableAiPanelContexts } from '../../domain/aiPanelContextsEqual';
+import {
+  buildAITerminalSessionInfo,
+  type AIPanelContext,
+} from '../../domain/buildAITerminalSessionInfo';
+import { collectSessionIds } from '../../domain/workspace';
+import type { TerminalContextReader } from '../../domain/terminalContextRead';
+import { detectLocalOs } from '../../lib/localShell';
+import type { Host, PortForwardingRule, TerminalSession, Workspace } from '../../types';
+
+interface UseTerminalAiContextsOptions {
+  hosts: Host[];
+  hostsRef: React.MutableRefObject<Host[]>;
+  portForwardingRules: PortForwardingRule[];
+  portForwardingRulesRef: React.MutableRefObject<PortForwardingRule[]>;
+  mountedAiTabIds: string[];
+  sessionHostsMap: Map<string, Host>;
+  sessions: TerminalSession[];
+  sessionsRef: React.MutableRefObject<TerminalSession[]>;
+  terminalContextReadersRef: React.MutableRefObject<Map<string, TerminalContextReader>>;
+  workspaces: Workspace[];
+  workspacesRef: React.MutableRefObject<Workspace[]>;
+}
+
+export function useTerminalAiContexts({
+  hosts,
+  hostsRef,
+  portForwardingRules,
+  portForwardingRulesRef,
+  mountedAiTabIds,
+  sessionHostsMap,
+  sessions,
+  sessionsRef,
+  terminalContextReadersRef,
+  workspaces,
+  workspacesRef,
+}: UseTerminalAiContextsOptions) {
+  const previousAiContextsRef = useRef<Map<string, AIPanelContext> | null>(null);
+  const aiContextsByTabId = useMemo(() => {
+    const localOs = detectLocalOs(navigator.userAgent || navigator.platform);
+    const sessionById = new Map<string, TerminalSession>(sessions.map((session) => [session.id, session]));
+    const workspaceById = new Map<string, Workspace>(workspaces.map((workspace) => [workspace.id, workspace]));
+    const allHosts = hosts;
+    const tabIds = new Set<string>(mountedAiTabIds);
+
+    const contexts = new Map<string, AIPanelContext>();
+
+    for (const tabId of tabIds) {
+      const workspace = workspaceById.get(tabId);
+      if (workspace) {
+        const sessionIds = collectSessionIds(workspace.root);
+        contexts.set(tabId, {
+          scopeType: 'workspace',
+          scopeTargetId: workspace.id,
+          scopeHostIds: sessionIds
+            .map((sessionId) => sessionById.get(sessionId)?.hostId)
+            .filter((hostId): hostId is string => !!hostId),
+          scopeLabel: workspace.title,
+          terminalSessions: sessionIds.map((sessionId) =>
+            buildAITerminalSessionInfo(
+              sessionById.get(sessionId),
+              sessionHostsMap.get(sessionId),
+              localOs,
+              { allHosts, portForwardingRules },
+            ),
+          ),
+        });
+        continue;
+      }
+
+      const session = sessionById.get(tabId);
+      if (!session) continue;
+
+      contexts.set(tabId, {
+        scopeType: 'terminal',
+        scopeTargetId: session.id,
+        scopeHostIds: session.hostId ? [session.hostId] : [],
+        scopeLabel: session.hostLabel ?? '',
+        terminalSessions: [
+          buildAITerminalSessionInfo(
+            session,
+            sessionHostsMap.get(session.id),
+            localOs,
+            { allHosts, portForwardingRules },
+          ),
+        ],
+      });
+    }
+
+    const retained = retainStableAiPanelContexts(previousAiContextsRef.current, contexts);
+    previousAiContextsRef.current = retained;
+    return retained;
+  }, [sessions, workspaces, mountedAiTabIds, sessionHostsMap, hosts, portForwardingRules]);
+
+  const resolveAIExecutorContext = useCallback((scope: {
+    type: 'terminal' | 'workspace';
+    targetId?: string;
+    label?: string;
+  }) => {
+    const latestWorkspaces = workspacesRef.current;
+    const latestSessions = sessionsRef.current;
+    const latestHosts = hostsRef.current;
+    const localOs = detectLocalOs(navigator.userAgent || navigator.platform);
+    const sessionIds = scope.type === 'workspace'
+      ? (() => {
+          const workspace = scope.targetId ? latestWorkspaces.find((w) => w.id === scope.targetId) : undefined;
+          return workspace?.root ? collectSessionIds(workspace.root) : [];
+        })()
+      : scope.targetId ? [scope.targetId] : [];
+
+    const workspaceName = scope.type === 'workspace'
+      ? latestWorkspaces.find((w) => w.id === scope.targetId)?.title ?? scope.label
+      : undefined;
+
+    return {
+      sessions: sessionIds.map((sid) => {
+        const session = latestSessions.find((s) => s.id === sid);
+        const host = session ? sessionHostsMap.get(session.id) : undefined;
+        return buildAITerminalSessionInfo(session, host, localOs, {
+          allHosts: latestHosts,
+          portForwardingRules: portForwardingRulesRef.current,
+        });
+      }),
+      workspaceId: scope.type === 'workspace' ? scope.targetId : undefined,
+      workspaceName,
+      readTerminalContext: (request: Parameters<TerminalContextReader>[0]) => {
+        const reader = terminalContextReadersRef.current.get(request.sessionId);
+        if (!reader) {
+          return Promise.resolve({
+            ok: false as const,
+            error: `Terminal session "${request.sessionId}" has no readable terminal buffer.`,
+          });
+        }
+        return reader(request);
+      },
+    };
+  }, [hostsRef, portForwardingRulesRef, sessionHostsMap, sessionsRef, terminalContextReadersRef, workspacesRef]);
+
+  return {
+    aiContextsByTabId,
+    resolveAIExecutorContext,
+  };
+}