Merge pull request #8748 from ttmouse/pr/chat-panel-resize-min-400

feat(desktop): refine workspace dock sizing and state / 优化工作区面板宽度与状态管理
2026-11-07 10:45:59 -10:00 · 2026-08-20 16:23:06 +08:00
commit 3bc93c07a3
@@ -17,7 +17,7 @@
    "test:terminal": "tsx src/__tests__/terminal-events.test.ts && tsx src/__tests__/terminal-store.test.ts && tsx src/__tests__/terminal-output.test.ts && tsx src/__tests__/terminal-theme.test.ts && tsx src/__tests__/terminal-selection.test.ts && tsx src/__tests__/workspace-layout.test.ts",
    "test:usage-stats": "tsx src/__tests__/usage-stats-format.test.ts && tsx src/__tests__/usage-stats-panel.test.tsx",
    "test:task-monitor": "tsx src/components/TaskMonitorPanel.test.tsx && tsx src/__tests__/task-monitor-navigation.test.ts",
-    "test:workspace": "tsx src/__tests__/keyed-resource.test.ts && tsx src/__tests__/workspace-tree-memory.test.ts && tsx src/__tests__/workspace-refresh-store.test.ts && tsx src/__tests__/workspace-changes-errors.test.tsx && tsx src/__tests__/workspace-turn-verification.test.tsx && tsx src/__tests__/workspace-preview-css.test.ts && tsx src/__tests__/workspace-context-menu.test.tsx && tsx src/__tests__/workspace-panel-swr-contract.test.ts",
+    "test:workspace": "tsx src/__tests__/keyed-resource.test.ts && tsx src/__tests__/workspace-tree-memory.test.ts && tsx src/__tests__/workspace-refresh-store.test.ts && tsx src/__tests__/workspace-selection-isolation.test.tsx && tsx src/__tests__/workspace-changes-errors.test.tsx && tsx src/__tests__/workspace-turn-verification.test.tsx && tsx src/__tests__/workspace-preview-css.test.ts && tsx src/__tests__/workspace-context-menu.test.tsx && tsx src/__tests__/workspace-resize-interaction.test.tsx && tsx src/__tests__/workspace-panel-swr-contract.test.ts",
    "test:settings-responsive": "tsx src/__tests__/settings-responsive-layout.test.ts",
    "test:stream": "tsx src/__tests__/raf-batch.test.ts && tsx src/__tests__/stream-delta-batch.test.ts && tsx src/__tests__/use-controller-stream-progress.test.ts",
    "test:motion": "node scripts/check-motion-ci-contract.mjs && node scripts/check-waapi-contract.mjs --self-test && tsx src/__tests__/native-motion.test.tsx && tsx src/__tests__/approval-animation.test.tsx",
@@ -121,7 +121,11 @@ const rawInitialBytes = [...initialJS, ...initialCSS, ...appShellCSS]
 // its combined diagnostic wiring adds 2.2 KiB (0.094%) to the test channel.
 // DingTalk startup wiring moves current-base production from 2341.0 to 2343.6
 // KiB and test from 2346.2 to 2348.8 KiB; the pinned heading adds 0.5 KiB raw
-// (0.021%). Preserve its scoped UI contract and 0.1 KiB build-SHA headroom.
-const rawInitialBudgetKiB = process.env.REASONIX_CHANNEL === "test" ? 2_349.4 : 2_344.2;
+// (0.021%). The workspace panel rework (change-row hover/revert, status badges,
+// More menu, completion summary) makes the latest-base merge 2353.1 KiB in
+// production and 2358.3 KiB in test: about 9.0 KiB (0.38%) over main-v2's
+// channel gates. Retain that attributable UI capacity with 0.1 KiB of build-SHA
+// headroom without widening the gzip or largest-chunk exceptions.
+const rawInitialBudgetKiB = process.env.REASONIX_CHANNEL === "test" ? 2_358.4 : 2_353.2;
 assertBudget("initial raw JavaScript and CSS", rawInitialBytes, rawInitialBudgetKiB * 1024);
 assertBudget("largest initial JavaScript chunk raw", largestInitialJSRaw, 1_000 * 1024);
@@ -23,9 +23,11 @@ const OWNED_ELSEWHERE = new Map(Object.entries({
  "terminal-theme.test.ts": "test:terminal",
  "task-monitor-navigation.test.ts": "test:task-monitor",
  "workspace-refresh-store.test.ts": "test:workspace",
+  "workspace-selection-isolation.test.tsx": "test:workspace",
  "workspace-changes-errors.test.tsx": "test:workspace",
  "workspace-preview-css.test.ts": "test:workspace",
  "workspace-context-menu.test.tsx": "test:workspace",
+  "workspace-resize-interaction.test.tsx": "test:workspace",
  "rich-composer-selection.test.tsx": "pretest",
  "context-center-contract.test.ts": "pretest",
  "provider-model-cache.test.ts": "pretest",
@@ -5,7 +5,6 @@ import {
  Activity,
  Command,
  Copy as RestoreIcon,
-  Download,
  Minus,
  Search,
  Server,
@@ -13,14 +12,10 @@ import {
  SquarePen,
  PanelLeft,
  PanelRight,
-  FileDown,
-  FileImage,
  FileText,
-  FileJson,
  GitBranch,
  MessageSquare,
  Settings as SettingsIcon,
-  Pencil,
  RotateCw,
  Trash2,
  AlarmClock,
@@ -75,6 +70,7 @@ import { HeartbeatPanel } from "./custom/features/heartbeat/HeartbeatPanel";
 import "./custom/features/heartbeat/heartbeat.css";
 import { CopyButton } from "./components/CopyButton";
 import { ExternalOpener, shouldMountExternalOpener } from "./components/ExternalOpener";
+import { TopicbarMoreMenu } from "./components/TopicbarMoreMenu";
 import { startTerminalEventBridge } from "./lib/terminalEvents";
 import { applyTerminalThemePreference } from "./lib/terminalTheme";
 import { formatTerminalOutputForComposer } from "./lib/terminalOutput";
@@ -145,11 +141,7 @@ import {
  CREATION_RIGHT_DOCK_MIN_RENDER_WIDTH,
  CREATION_RIGHT_DOCK_TREE_MIN_WIDTH,
  CREATION_SIDEBAR_MIN_WIDTH,
-  RIGHT_DOCK_MAX_WIDTH,
  RIGHT_DOCK_MIN_RENDER_WIDTH,
-  RIGHT_DOCK_PREVIEW_DEFAULT_WIDTH,
-  RIGHT_DOCK_PREVIEW_MIN_WIDTH,
-  RIGHT_DOCK_TREE_MAX_WIDTH,
  RIGHT_DOCK_TREE_MIN_WIDTH,
  type RightDockMode,
  SIDEBAR_MAX_WIDTH,
@@ -159,7 +151,6 @@ import {
  applyLayoutStyleDefaults,
  clampCreationRightDockTreeWidth,
  clampCreationSidebarWidth,
-  clampRightDockPreviewWidth,
  clampRightDockTreeWidth,
  clampSidebarWidth,
  clampTerminalHeight,
@@ -167,7 +158,6 @@ import {
  defaultCreationSidebarWidth,
  defaultRightDockTreeWidth,
  defaultSidebarWidth,
-  saveRightDockPreviewWidth,
  saveRightDockTreeWidth,
  saveSidebarCollapsed,
  saveSidebarWidth,
@@ -175,6 +165,7 @@ import {
  saveTerminalPanelOpen,
  terminalMaxHeight,
  saveWorkspacePanelOpen,
+  loadWorkspacePanelOpen,
  useLayoutStore,
 } from "./store/layout";
 import { useOverlayStore } from "./store/overlays";
@@ -199,9 +190,9 @@ import { applyConfiguredBaseAppearance, applyThemePack, applyThemeScene, clearTh
 import { ThemeBackground } from "./components/ThemeBackground";
 import { applyTextSize, DEFAULT_TEXT_SIZE, getTextSize, nextTextSize } from "./lib/textSize";
 import { useViewportHeightVar, useWindowStatePersistence } from "./lib/windowState";
-import { resolveLiveWorkspacePanelWidth, resolveWorkspacePanelPlacement, workspacePanelAriaMinWidth } from "./lib/workspaceLayout";
+import { availableWorkspacePanelWidth, resolveLiveWorkspacePanelWidth, resolveWorkspacePanelPlacement, workspacePanelAriaMinWidth } from "./lib/workspaceLayout";
 import { createPointerResizeLifecycle, createRafResizeUpdater } from "./lib/resizeDrag";
-import { useGlobalShortcut } from "./lib/keyboardShortcuts";
+import { formatShortcutCombo, resolvedShortcutCombo, useGlobalShortcut } from "./lib/keyboardShortcuts";
 import { useWarmTerminalPanel } from "./lib/useWarmTerminalPanel";
 import { topicShortcutIndexFromEvent, useTopicShortcuts, type TopicShortcutEntry } from "./lib/topicShortcuts";
 import { composerDraftKeyForTab } from "./lib/composerDraftKey";
@@ -300,7 +291,6 @@ const WorkspacePanel = lazy(async () => {
 });

 const CHAT_MIN_WIDTH = 400;
-const CHAT_COMFORT_MIN_WIDTH = 560;
 const WORKSPACE_RESIZER_WIDTH = 8;

 function stripLegacyGoalBudgetFlags(arg: string): string {
@@ -1204,7 +1194,6 @@ export default function App() {
  const rightDockTreeWidth = useLayoutStore((s) => s.rightDockTreeWidth);
  const setRightDockTreeWidth = useLayoutStore((s) => s.setRightDockTreeWidth);
  const rightDockPreviewWidth = useLayoutStore((s) => s.rightDockPreviewWidth);
-  const setRightDockPreviewWidth = useLayoutStore((s) => s.setRightDockPreviewWidth);
  const workspacePreviewActive = useLayoutStore((s) => s.workspacePreviewActive);
  const setWorkspacePreviewActive = useLayoutStore((s) => s.setWorkspacePreviewActive);
  const attentionChimeEvents = useRef(new Set<string>());
@@ -1297,7 +1286,6 @@ export default function App() {
  const sidebarSearchFocusSignal = useOverlayStore((s) => s.sidebarSearchFocusSignal);
  const setSidebarSearchFocusSignal = useOverlayStore((s) => s.setSidebarSearchFocusSignal);
  const [sidebarTogglePressed, setSidebarTogglePressed] = useState(false);
-  const [workspaceTogglePressed, setWorkspaceTogglePressed] = useState(false);
  const [clearContextPending, setClearContextPending] = useState(false);
  const [backgroundRuntimes, setBackgroundRuntimes] = useState<BackgroundRuntimeView[]>([]);
  const [workspaceConflict, setWorkspaceConflict] = useState<WorkspaceConflictView | null>(null);
@@ -1310,7 +1298,6 @@ export default function App() {
  const layoutRef = useRef<HTMLDivElement>(null);
  const workspacePanelResizeFinishRef = useRef<(() => void) | null>(null);
  const sidebarTogglePressTimerRef = useRef<number | null>(null);
-  const workspaceTogglePressTimerRef = useRef<number | null>(null);

  // Persist window geometry across launches.
  useWindowStatePersistence();
@@ -1410,18 +1397,6 @@ export default function App() {
    }, 260);
  }, []);

-  const pulseWorkspaceToggle = useCallback(() => {
-    if (typeof window === "undefined") return;
-    if (workspaceTogglePressTimerRef.current !== null) {
-      window.clearTimeout(workspaceTogglePressTimerRef.current);
-    }
-    setWorkspaceTogglePressed(true);
-    workspaceTogglePressTimerRef.current = window.setTimeout(() => {
-      workspaceTogglePressTimerRef.current = null;
-      setWorkspaceTogglePressed(false);
-    }, 260);
-  }, []);
-
  const anchorAppScrollToChat = useCallback(() => {
    if (typeof window === "undefined") return;
    const el = appRef.current;
@@ -1439,9 +1414,6 @@ export default function App() {
      if (sidebarTogglePressTimerRef.current !== null) {
        window.clearTimeout(sidebarTogglePressTimerRef.current);
      }
-      if (workspaceTogglePressTimerRef.current !== null) {
-        window.clearTimeout(workspaceTogglePressTimerRef.current);
-      }
    };
  }, []);

@@ -1592,14 +1564,24 @@ export default function App() {
    });
  }, []);
  const rightDockDetailActive = rightDockMode !== "context" && workspacePreviewActive;
-  const preferredWorkspacePanelWidth = rightDockDetailActive ? rightDockPreviewWidth : rightDockTreeWidth;
+  // The dock keeps one width across tab switches (context/files/changed):
+  // the tree width is the single source so toggling tabs never resizes the
+  // sidebar. Preview detail stays inside the dock without widening it.
+  const preferredWorkspacePanelWidth = rightDockTreeWidth;
  const rightDockTreeMinWidth = desktopLayoutStyle === "creation" ? CREATION_RIGHT_DOCK_TREE_MIN_WIDTH : RIGHT_DOCK_TREE_MIN_WIDTH;
  const rightDockTreeWidthClamp = desktopLayoutStyle === "creation" ? clampCreationRightDockTreeWidth : clampRightDockTreeWidth;
  const rightDockMinRenderWidth = desktopLayoutStyle === "creation" && !rightDockDetailActive
    ? CREATION_RIGHT_DOCK_MIN_RENDER_WIDTH
    : RIGHT_DOCK_MIN_RENDER_WIDTH;
-  const workspacePanelMinWidth = rightDockDetailActive ? RIGHT_DOCK_PREVIEW_MIN_WIDTH : rightDockTreeMinWidth;
-  const chatReservedWidth = workspacePanelOpen && !workspacePanelMaximized ? CHAT_COMFORT_MIN_WIDTH : CHAT_MIN_WIDTH;
+  const workspacePanelMinWidth = rightDockTreeMinWidth;
+  const chatReservedWidth = CHAT_MIN_WIDTH;
+  const workspacePanelAvailableWidth = availableWorkspacePanelWidth({
+    viewportWidth,
+    sidebarCollapsed,
+    sidebarWidth,
+    chatMinWidth: chatReservedWidth,
+    resizerWidth: WORKSPACE_RESIZER_WIDTH,
+  });
  const {
    renderWidth: workspacePanelRenderWidth,
    overlay: workspacePanelOverlay,
@@ -1667,10 +1649,12 @@ export default function App() {
    activeTab?.scope ?? "",
    activeTab?.workspaceRoot ?? state.meta?.cwd ?? "",
  ].join("\u0000");
-  const restoreWorkspaceDockWidths = useCallback((treeWidth: number, previewWidth: number) => {
-    setRightDockTreeWidth(rightDockTreeWidthClamp(treeWidth));
-    setRightDockPreviewWidth(clampRightDockPreviewWidth(previewWidth));
-  }, [rightDockTreeWidthClamp]);
+  const restoreWorkspaceDockWidths = useCallback((treeWidth: number, _previewWidth: number) => {
+    // Single-width dock: only the tree width is meaningful; clamp it to the
+    // dynamic available width (chat keeps its 400px floor), never a fixed
+    // 560 ceiling, so the user's remembered width is preserved when reopened.
+    setRightDockTreeWidth(rightDockTreeWidthClamp(treeWidth, workspacePanelAvailableWidth));
+  }, [rightDockTreeWidthClamp, workspacePanelAvailableWidth]);
  const sidebarImDetailConnection = useMemo(
    () => sidebarImConnections.find((connection) => connection.id === sidebarImDetailConnectionId) ?? null,
    [sidebarImConnections, sidebarImDetailConnectionId],
@@ -2717,28 +2701,22 @@ export default function App() {
  const setSavedWorkspacePanelWidth = useCallback(
    (width: number) => {
      closeTransientOverlays();
-      if (rightDockDetailActive) {
-        const next = clampRightDockPreviewWidth(width);
-        setRightDockPreviewWidth(next);
-        saveRightDockPreviewWidth(next);
-        return;
-      }
-      const next = rightDockTreeWidthClamp(width);
+      const next = rightDockTreeWidthClamp(width, workspacePanelAvailableWidth);
      setRightDockTreeWidth(next);
      saveRightDockTreeWidth(next);
    },
-    [closeTransientOverlays, rightDockDetailActive, rightDockTreeWidthClamp],
+    [closeTransientOverlays, rightDockTreeWidthClamp, workspacePanelAvailableWidth],
  );

  const ensureWorkspacePanelWidth = useCallback(
    (width: number) => {
      closeTransientOverlays();
      if (rightDockMode === "context") return;
-      const next = clampRightDockPreviewWidth(width);
-      setRightDockPreviewWidth(next);
-      saveRightDockPreviewWidth(next);
+      const next = rightDockTreeWidthClamp(width, workspacePanelAvailableWidth);
+      setRightDockTreeWidth(next);
+      saveRightDockTreeWidth(next);
    },
-    [closeTransientOverlays, rightDockMode],
+    [closeTransientOverlays, rightDockTreeWidthClamp, workspacePanelAvailableWidth],
  );

  const startWorkspacePanelResize = useCallback(
@@ -2764,11 +2742,7 @@ export default function App() {
      const onMove = (moveEvent: PointerEvent) => {
        const delta = moveEvent.clientX - startX;
        nextDockWidth = startDockWidth - delta;
-        if (rightDockDetailActive) {
-          nextDockWidth = clampRightDockPreviewWidth(nextDockWidth);
-        } else {
-          nextDockWidth = rightDockTreeWidthClamp(nextDockWidth);
-        }
+        nextDockWidth = rightDockTreeWidthClamp(nextDockWidth, workspacePanelAvailableWidth);
        liveResize.schedule(resolveLiveWorkspacePanelRenderWidth(nextDockWidth));
      };
      const lifecycle = createPointerResizeLifecycle({
@@ -2789,7 +2763,7 @@ export default function App() {
      document.body.style.cursor = "col-resize";
      document.body.style.userSelect = "none";
    },
-    [closeTransientOverlays, resolveLiveWorkspacePanelRenderWidth, rightDockDetailActive, rightDockTreeWidthClamp, setSavedWorkspacePanelWidth, workspacePanelOpen, workspacePanelRenderWidth],
+    [closeTransientOverlays, resolveLiveWorkspacePanelRenderWidth, rightDockDetailActive, rightDockTreeWidthClamp, setSavedWorkspacePanelWidth, workspacePanelAvailableWidth, workspacePanelOpen, workspacePanelRenderWidth],
  );

  const resizeWorkspacePanelWithKeyboard = useCallback(
@@ -2799,13 +2773,13 @@ export default function App() {
        setSavedWorkspacePanelWidth(workspacePanelRenderWidth + (event.key === "ArrowLeft" ? 16 : -16));
      } else if (event.key === "Home") {
        event.preventDefault();
-        setSavedWorkspacePanelWidth(rightDockDetailActive ? RIGHT_DOCK_PREVIEW_MIN_WIDTH : rightDockTreeMinWidth);
+        setSavedWorkspacePanelWidth(rightDockTreeMinWidth);
      } else if (event.key === "End") {
        event.preventDefault();
-        setSavedWorkspacePanelWidth(rightDockDetailActive ? RIGHT_DOCK_MAX_WIDTH : RIGHT_DOCK_TREE_MAX_WIDTH);
+        setSavedWorkspacePanelWidth(workspacePanelAvailableWidth);
      }
    },
-    [rightDockDetailActive, rightDockTreeMinWidth, setSavedWorkspacePanelWidth, workspacePanelRenderWidth],
+    [rightDockDetailActive, rightDockTreeMinWidth, setSavedWorkspacePanelWidth, workspacePanelAvailableWidth, workspacePanelRenderWidth],
  );

  const terminalRenderHeight = clampTerminalHeight(terminalHeight, viewportHeight);
@@ -2876,6 +2850,8 @@ export default function App() {
    [setSavedTerminalHeight, terminalPanelOpen, terminalRenderHeight, terminalResizeMaxHeight],
  );

+  const activeWorkspaceRoot = activeTab?.workspaceRoot ?? state.meta?.cwd ?? "";
+
  const openWorkspacePanel = useCallback(
    (mode: RightDockMode = rightDockMode) => {
      closeTransientOverlays();
@@ -2897,9 +2873,9 @@ export default function App() {
        return;
      }
      setWorkspacePanelOpen(true);
-      saveWorkspacePanelOpen(true);
+      saveWorkspacePanelOpen(true, activeWorkspaceRoot);
    },
-    [closeTransientOverlays, rightDockMode, workspacePanelMaximized, workspacePanelOpen],
+    [activeWorkspaceRoot, closeTransientOverlays, rightDockMode, workspacePanelMaximized, workspacePanelOpen],
  );

  const closeWorkspacePanel = useCallback(() => {
@@ -2910,11 +2886,18 @@ export default function App() {
    setLiveWorkspacePanelRenderWidth(null);
    setWorkspacePanelMaximized(false);
    setWorkspacePanelOpen(false);
-    saveWorkspacePanelOpen(false);
-  }, [closeTransientOverlays, workspacePanelOpen]);
+    saveWorkspacePanelOpen(false, activeWorkspaceRoot);
+  }, [activeWorkspaceRoot, closeTransientOverlays, workspacePanelOpen]);
+
+  // Restore the right dock's open/closed state per project: switching to a
+  // different workspace root (or a global session) restores that scope's own
+  // preference instead of carrying the previous project's state over.
+  useEffect(() => {
+    setWorkspacePanelOpen(loadWorkspacePanelOpen(activeWorkspaceRoot));
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [activeWorkspaceRoot]);

  const toggleWorkspacePanel = useCallback(() => {
-    pulseWorkspaceToggle();
    if (workspacePanelRenderable) {
      closeWorkspacePanel();
      return;
@@ -2925,8 +2908,10 @@ export default function App() {
      openWorkspacePanel(rightDockMode === "changed" ? "changed" : "files");
      return;
    }
-    openWorkspacePanel("context");
-  }, [closeWorkspacePanel, desktopLayoutStyle, openWorkspacePanel, pulseWorkspaceToggle, rightDockMode, workspacePanelRenderable]);
+    // Reopen with the previously active tab (rightDockMode is kept in the
+    // store across close/open) instead of forcing "context".
+    openWorkspacePanel();
+  }, [closeWorkspacePanel, desktopLayoutStyle, openWorkspacePanel, rightDockMode, workspacePanelRenderable]);

  const openRightDockMode = useCallback(
    (mode: RightDockMode) => {
@@ -4221,14 +4206,36 @@ export default function App() {
  const browserPreviewChrome = typeof window !== "undefined" && !window.runtime;
  const browserMockScenario = browserPreviewChrome ? browserMockScenarioParam() : "";
  const guidanceQueueMockItems = isGuidanceMockScenario(browserMockScenario) ? GUIDANCE_QUEUE_MOCK_ITEMS : undefined;
-  const workspacePanelResetWidth = rightDockDetailActive
-    ? RIGHT_DOCK_PREVIEW_DEFAULT_WIDTH
-    : desktopLayoutStyle === "creation"
-      ? defaultCreationRightDockTreeWidth()
-      : defaultRightDockTreeWidth();
+  const workspacePanelResetWidth = desktopLayoutStyle === "creation"
+    ? defaultCreationRightDockTreeWidth()
+    : defaultRightDockTreeWidth();
  const workspacePanelResizeMinWidth = workspacePanelAriaMinWidth(workspacePanelMinWidth, workspacePanelRenderWidth);
-  const workspacePanelMaxWidth = rightDockDetailActive ? RIGHT_DOCK_MAX_WIDTH : RIGHT_DOCK_TREE_MAX_WIDTH;
+  const workspacePanelResizeMaxWidth = workspacePanelAvailableWidth;
  const sidebarCreation = desktopLayoutStyle === "creation";
+  // Command palette shortcut label (⌘K / Ctrl+K), platform-aware.
+  const commandPaletteShortcut = formatShortcutCombo(
+    resolvedShortcutCombo("commandPalette.open", desktopPlatform),
+    desktopPlatform,
+  );
+  // Dock collapse/expand toggle. Rendered in the dock's own tools row when the
+  // dock is open (its top-right corner), and in the topic bar when closed.
+  const dockToggleButton = (
+    <Tooltip label={workspacePanelRenderable ? t("rightDock.collapse") : t("rightDock.expand")}>
+      <button
+        className={[
+          "topicbar__chrome-btn",
+          "topicbar__chrome-btn--workspace",
+          workspacePanelRenderable ? "topicbar__chrome-btn--active" : "",
+        ].filter(Boolean).join(" ")}
+        type="button"
+        onClick={toggleWorkspacePanel}
+        aria-label={workspacePanelRenderable ? t("rightDock.collapse") : t("rightDock.expand")}
+        aria-pressed={workspacePanelRenderable}
+      >
+        <PanelRight size={15} />
+      </button>
+    </Tooltip>
+  );
  const topicbarTitle = sidebarImDetailConnection ? t("botDetail.title", { name: sidebarImDetailConnection.title }) : topicDisplayTitle(activeTab);
  const topicbarWorkspaceLabel = sidebarImDetailConnection ? t("botDetail.subtitle") : activeTab ? tabWorkspaceTitle(activeTab) : "";
  const topicbarWorkspacePath = activeTab?.scope === "project" ? activeTab.workspaceRoot || state.meta?.cwd : "";
@@ -4237,7 +4244,7 @@ export default function App() {
    ? sidebarImDetailConnection.platformLabel
    : topicbarImSource ? t("msg.fromIm", { source: topicbarImSource.label }) : "";
  const topicbarImSourcePlatform = sidebarImDetailConnection?.platform ?? topicbarImSource?.platform;
-  const topicbarSubtitleVisible = !sidebarCreation && Boolean(topicbarWorkspaceLabel || topicbarImSourceLabel);
+  const topicbarSubtitleVisible = !sidebarCreation && Boolean(activeTab?.isolatedWorktree || topicbarImSourceLabel);
  const topicbarSubtitleTitle = sidebarImDetailConnection
    ? [topicbarWorkspaceLabel, topicbarImSourceLabel, sidebarImScopeLabel(sidebarImDetailConnection, t)].filter(Boolean).join(" · ")
    : [topicbarWorkspacePath || topicbarWorkspaceLabel, topicbarImSourceLabel].filter(Boolean).join(" · ");
@@ -4289,6 +4296,7 @@ export default function App() {
      ].filter(Boolean).join(" ")}
    >
      <ThemeBackground />
+      {sidebarWorkbench && <div className="app__dock-toggle">{dockToggleButton}</div>}
      <div
        ref={layoutRef}
        className={[
@@ -4326,7 +4334,6 @@ export default function App() {
            sidebarToggleTitle={sidebarToggleTitle}
            workspacePanelMaximized={workspacePanelMaximized}
            workspacePanelRenderable={workspacePanelRenderable}
-            workspaceTogglePressed={workspaceTogglePressed}
            workspacePanelLabel={workspacePanelRenderable ? t("rightDock.collapse") : t("rightDock.expand")}
            onToggleSidebar={toggleSidebar}
            onToggleWorkspacePanel={toggleWorkspacePanel}
@@ -4609,6 +4616,7 @@ export default function App() {
                      size={sidebarCreation ? topicbarTitleEditSize : undefined}
                      value={topicTitleDraft}
                      onChange={(event) => setTopicTitleDraft(event.target.value)}
+                      onFocus={(event) => event.currentTarget.select()}
                      onKeyDown={(event: KeyboardEvent<HTMLInputElement>) => {
                        if (event.key === "Enter") {
                          event.preventDefault();
@@ -4622,7 +4630,7 @@ export default function App() {
                      onBlur={() => void commitActiveTopicRename()}
                    />
                  </div>
-                ) : sidebarCreation && topicbarCanRename ? (
+                ) : topicbarCanRename ? (
                  <h1 title={topicTitle(activeTab)}>
                    <button
                      className="topicbar__title-button"
@@ -4636,23 +4644,14 @@ export default function App() {
                ) : (
                  <h1 title={sidebarImDetailConnection ? topicbarTitle : topicTitle(activeTab)}>{topicbarTitle}</h1>
                )}
-                {!sidebarCreation && (
-                  <Tooltip label={t("topicBar.renameSession")}>
-                    <button
-                      className="topicbar__icon-btn"
-                      type="button"
-                      disabled={!topicbarCanRename || topicbarEditing}
-                      onClick={startActiveTopicRename}
-                      aria-label={t("topicBar.renameSession")}
-                    >
-                      <Pencil size={14} />
-                    </button>
-                  </Tooltip>
+                {topicbarWorkspaceLabel && (
+                  <span className="topicbar__workspace-label" title={topicbarWorkspaceLabel}>
+                    {topicbarWorkspaceLabel}
+                  </span>
                )}
              </div>
              {topicbarSubtitleVisible && (
                <div className="topicbar__subtitle" title={topicbarSubtitleTitle}>
-                  {topicbarWorkspaceLabel && <span>{topicbarWorkspaceLabel}</span>}
                  {activeTab?.isolatedWorktree && <WorktreeBadge size={11} />}
                  {topicbarImSourcePlatform && (
                    <span className={`topicbar__source-chip topicbar__source-chip--${topicbarImSourcePlatform}`}>
@@ -4664,116 +4663,32 @@ export default function App() {
            </div>
            <div className="topicbar__spacer" />
            <div className="topicbar__actions">
-              {sidebarCreation && shouldMountExternalOpener(activeTab, Boolean(sidebarImDetailConnection)) && activeTab && (
-                <ExternalOpener key={activeTab.id} tabId={activeTab.id} dismissSignal={transientOverlayDismissSignal} />
-              )}
-              {!sidebarImDetailConnection && (
-              <>
-              <Tooltip label={t("topicBar.copyAll")}>
-                <CopyButton
-                  getText={getSessionMarkdown}
-                  label={t("topicBar.copyAll")}
-                  className="topicbar__action-btn topicbar__action-btn--icon topicbar__action-btn--utility"
-                  showInlineLabel={false}
-                />
-              </Tooltip>
-              <div className={`topicbar__export${topicExportOpen ? " topicbar__export--open" : ""}`}>
-                <Tooltip label={t("topicBar.export")}>
-                  <button
-                    className="topicbar__action-btn topicbar__action-btn--icon topicbar__action-btn--utility"
-                    type="button"
-                    disabled={!sessionHasContent}
-                    aria-label={t("topicBar.export")}
-                    aria-haspopup="menu"
-                    aria-expanded={topicExportOpen}
-                    onClick={() => setTopicExportOpen((open) => !open)}
-                  >
-                    <Download size={14} />
-                  </button>
-                </Tooltip>
-                {topicExportOpen && (
-                  <div className="topicbar__export-menu" role="menu">
-                    <button type="button" role="menuitem" onClick={() => void exportSession("markdown")}>
-                      <FileText size={13} />
-                      <span>{t("topicBar.exportMarkdown")}</span>
-                    </button>
-                    <button type="button" role="menuitem" onClick={() => void exportSession("json")}>
-                      <FileJson size={13} />
-                      <span>{t("topicBar.exportJson")}</span>
-                    </button>
-                    <button type="button" role="menuitem" onClick={() => void exportSession("pdf")}>
-                      <FileDown size={13} />
-                      <span>{t("topicBar.exportPdf")}</span>
-                    </button>
-                    <button type="button" role="menuitem" onClick={() => void exportSession("image")}>
-                      <FileImage size={13} />
-                      <span>{t("topicBar.exportImage")}</span>
-                    </button>
-                  </div>
-                )}
-              </div>
-              </>
-              )}
-              {!sidebarCreation && (
-                <Tooltip label={t("workspace.changedTab")}>
-                  <button
-                    className="topicbar__action-btn topicbar__action-btn--label"
-                    type="button"
-                    aria-label={t("workspace.changedTab")}
-                    aria-pressed={workspacePanelRenderable && rightDockMode === "changed"}
-                    onClick={() => openRightDockMode("changed")}
-                  >
-                    <GitBranch size={14} />
-                    <span>{t("workspace.changedTab")}</span>
-                  </button>
-                </Tooltip>
-              )}
-              {!sidebarImDetailConnection && (
-                <Tooltip label={t("rightDock.terminal")}>
-                  <button
-                    className="topicbar__action-btn topicbar__action-btn--icon topicbar__action-btn--utility"
-                    type="button"
-                    aria-label={t("rightDock.terminal")}
-                    aria-pressed={terminalPanelOpen}
-                    onPointerEnter={prefetchTerminalPanel} onFocus={prefetchTerminalPanel}
-                    onClick={toggleTerminalPanel}
-                  >
-                    <TerminalSquare size={14} />
-                  </button>
-                </Tooltip>
-              )}
-              {!sidebarCreation && shouldMountExternalOpener(activeTab, Boolean(sidebarImDetailConnection)) && activeTab && (
-                <ExternalOpener key={activeTab.id} tabId={activeTab.id} dismissSignal={transientOverlayDismissSignal} />
-              )}
-              <Tooltip label={t("summary.session")}>
+              <Tooltip label={`${t("shortcuts.action.commandPalette")} ${commandPaletteShortcut}`}>
                <button
-                  className={`topicbar__action-btn topicbar__action-btn--icon topicbar__action-btn--utility${tasksOpen ? " topicbar__action-btn--active" : ""}`}
+                  className="topicbar__action-btn topicbar__action-btn--icon topicbar__action-btn--utility"
                  type="button"
-                  aria-label={t("summary.session")}
-                  aria-expanded={Boolean(tasksOpen)}
-                  onClick={() => setTasksOpen((open) => open ? false : "session")}
+                  aria-label={t("shortcuts.action.commandPalette")}
+                  onClick={() => void openPalette()}
                >
-                  <Activity size={14} />
+                  <Search size={15} />
                </button>
              </Tooltip>
-              {(sidebarCreation || workbenchChromeHidden) && (
-                <Tooltip label={workspacePanelRenderable ? t("rightDock.collapse") : t("rightDock.expand")}>
-                  <button
-                    className={[
-                      "topicbar__chrome-btn",
-                      "topicbar__chrome-btn--workspace",
-                      workspacePanelRenderable ? "topicbar__chrome-btn--active" : "",
-                      workspaceTogglePressed ? "topicbar__chrome-btn--pressed" : "",
-                    ].filter(Boolean).join(" ")}
-                    type="button"
-                    onClick={toggleWorkspacePanel}
-                    aria-label={workspacePanelRenderable ? t("rightDock.collapse") : t("rightDock.expand")}
-                    aria-pressed={workspacePanelRenderable}
-                  >
-                    <PanelRight size={15} />
-                  </button>
-                </Tooltip>
+              {shouldMountExternalOpener(activeTab, Boolean(sidebarImDetailConnection)) && activeTab && (
+                <ExternalOpener key={activeTab.id} tabId={activeTab.id} dismissSignal={transientOverlayDismissSignal} />
              )}
+              {!sidebarImDetailConnection && (
+                <TopicbarMoreMenu
+                  sessionHasContent={sessionHasContent}
+                  getSessionMarkdown={getSessionMarkdown}
+                  exportSession={(format) => void exportSession(format)}
+                  openChangedDock={() => openRightDockMode("changed")}
+                  toggleTerminal={toggleTerminalPanel}
+                  prefetchTerminal={prefetchTerminalPanel}
+                  openSessionSummary={() => setTasksOpen((open) => open ? false : "session")}
+                  tasksOpen={Boolean(tasksOpen)}
+                />
+              )}
+              {sidebarCreation && dockToggleButton}
              {tasksOpen && (
                <div className="taskmonitor-popover" role="dialog" aria-label={t("summary.session")}>
                  <Suspense fallback={null}>
@@ -5162,7 +5077,7 @@ export default function App() {
            aria-orientation="vertical"
            aria-label={t("rightDock.resize")}
            aria-valuemin={workspacePanelResizeMinWidth}
-            aria-valuemax={Math.max(workspacePanelMaxWidth, workspacePanelRenderWidth)}
+            aria-valuemax={Math.max(workspacePanelResizeMaxWidth, workspacePanelRenderWidth)}
            aria-valuenow={workspacePanelRenderWidth}
            onPointerDown={startWorkspacePanelResize}
            onKeyDown={resizeWorkspacePanelWithKeyboard}
@@ -5254,6 +5169,7 @@ export default function App() {
              ) : (
                <Suspense fallback={null}>
                  <WorkspacePanel
+                    key={workspaceTreeMemoryKey}
                    open={workspacePanelRenderable}
                    tabId={activeTabId}
                    cwd={state.meta?.cwd}
@@ -279,10 +279,10 @@ ok(

 ok(
  /const WORKSPACE_PANEL_DEFAULT_OPEN = true;/.test(layoutStoreSource) &&
-    /workspacePanelOpen:\s*loadWorkspacePanelOpen\(\)/.test(layoutStoreSource) &&
-    /export function saveWorkspacePanelOpen\(open: boolean\)/.test(layoutStoreSource) &&
+    /workspacePanelOpen:\s*loadWorkspacePanelOpen\(""\)/.test(layoutStoreSource) &&
+    /export function saveWorkspacePanelOpen\(open: boolean, workspaceRoot = ""\)/.test(layoutStoreSource) &&
    /reasonix\.workspacePanel\.open/.test(layoutStoreSource),
-  "right dock open state is restored from localStorage with expanded first-launch default",
+  "right dock open state is restored from per-project localStorage with expanded first-launch default",
 );

 ok(
@@ -502,7 +502,7 @@ ok(

 ok(
  /const transcriptHydrating = state\.hydrating && !state\.hydrateHistoryLoaded;/.test(appSource) &&
-    /hydrating=\{transcriptHydrating\}/.test(appSource),
+    /hydrating=\{runtimeTransitioning \|\| transcriptHydrating\}/.test(appSource),
  "Welcome is suppressed only until transcript history has loaded",
 );

@@ -689,8 +689,8 @@ ok(
 );

 ok(
-  finalDeclaration(":root[data-theme-style] .workbench-dock__tab--active::after", "bottom") === "1px",
-  "active dock underline stays inside the visible dock edge",
+  finalDeclaration(":root[data-theme-style] .workbench-dock__tab--active::after", "display") === "none",
+  "active dock tab underline is removed in favor of the rounded-rect selected state",
 );

 for (const selector of [
@@ -7,13 +7,17 @@ import { fileURLToPath } from "node:url";

 const testDir = dirname(fileURLToPath(import.meta.url));
 const appSource = readFileSync(resolve(testDir, "../App.tsx"), "utf8");
+const moreMenuSource = [
+  readFileSync(resolve(testDir, "../components/TopicbarMoreMenu.tsx"), "utf8"),
+  readFileSync(resolve(testDir, "../components/TopicbarMoreMenuContent.tsx"), "utf8"),
+].join("\n");

 assert.doesNotMatch(appSource, /t\("shortcuts\.cheatsheetTitle"\)|t\("topicBar\.command"\)/);

-const taskSummaryControlIndex = appSource.indexOf('<Tooltip label={t("summary.session")}>');
+const taskSummaryControlIndex = moreMenuSource.indexOf('t("summary.session")');
 const workspaceToggleIndex = appSource.indexOf('<Tooltip label={workspacePanelRenderable ? t("rightDock.collapse") : t("rightDock.expand")}>');
 assert.ok(taskSummaryControlIndex >= 0, "topic bar renders the localized Session summary control");
-assert.ok(workspaceToggleIndex > taskSummaryControlIndex, "Session summary precedes the right-edge workspace toggle");
-assert.ok(!appSource.includes('aria-label="Session summary"'), "Session summary does not use a hard-coded English label");
+assert.ok(workspaceToggleIndex >= 0, "topic bar keeps the right-edge workspace toggle");
+assert.ok(!moreMenuSource.includes('aria-label="Session summary"'), "Session summary does not use a hard-coded English label");

 process.stdout.write("topicbar controls: 2 contracts passed\n");
@@ -0,0 +1,170 @@
+// Run: tsx src/__tests__/topicbar-more-menu.test.tsx
+
+import { JSDOM } from "jsdom";
+import { registerHooks } from "node:module";
+import React from "react";
+import { act } from "react";
+import { createRoot } from "react-dom/client";
+import { TopicbarMoreMenu } from "../components/TopicbarMoreMenu";
+import { LocaleProvider } from "../lib/i18n";
+
+registerHooks({
+  resolve(specifier, context, nextResolve) {
+    if (specifier.endsWith(".css")) {
+      return nextResolve("./asset-stub-for-tests.ts", { ...context, parentURL: import.meta.url });
+    }
+    return nextResolve(specifier, context);
+  },
+});
+
+let passed = 0;
+let failed = 0;
+
+function ok(value: boolean, label: string) {
+  if (value) {
+    process.stdout.write(`  PASS  ${label}\n`);
+    passed += 1;
+  } else {
+    process.stdout.write(`  FAIL  ${label}\n`);
+    failed += 1;
+  }
+}
+
+function flushTimers(): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, 0));
+}
+
+async function waitFor(label: string, predicate: () => boolean) {
+  for (let attempt = 0; attempt < 30; attempt += 1) {
+    await act(async () => {
+      await flushTimers();
+    });
+    if (predicate()) return;
+  }
+  throw new Error(`timed out waiting for ${label}`);
+}
+
+const dom = new JSDOM("<!doctype html><html><body><div id=\"root\"></div></body></html>", {
+  pretendToBeVisual: true,
+  url: "http://localhost/",
+});
+(globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+globalThis.window = dom.window as unknown as Window & typeof globalThis;
+globalThis.document = dom.window.document;
+Object.defineProperty(globalThis, "navigator", { configurable: true, value: dom.window.navigator });
+globalThis.Node = dom.window.Node;
+globalThis.HTMLElement = dom.window.HTMLElement;
+globalThis.Event = dom.window.Event;
+globalThis.KeyboardEvent = dom.window.KeyboardEvent;
+globalThis.MouseEvent = dom.window.MouseEvent;
+globalThis.PointerEvent = dom.window.MouseEvent as unknown as typeof PointerEvent;
+globalThis.requestAnimationFrame = dom.window.requestAnimationFrame.bind(dom.window);
+globalThis.cancelAnimationFrame = dom.window.cancelAnimationFrame.bind(dom.window);
+
+function press(target: Element, key: string) {
+  target.dispatchEvent(new dom.window.KeyboardEvent("keydown", { key, bubbles: true, cancelable: true }));
+}
+
+function directMenuItems(menu: HTMLElement): HTMLButtonElement[] {
+  return Array.from(menu.querySelectorAll<HTMLButtonElement>('[role="menuitem"]'))
+    .filter((item) => item.closest('[role="menu"]') === menu);
+}
+
+console.log("\ntopicbar more menu keyboard navigation");
+
+const rootElement = document.getElementById("root");
+if (!rootElement) throw new Error("missing root");
+const root = createRoot(rootElement);
+
+await act(async () => {
+  root.render(
+    <LocaleProvider>
+      <TopicbarMoreMenu
+        sessionHasContent
+        getSessionMarkdown={() => "# Session"}
+        exportSession={() => {}}
+        openChangedDock={() => {}}
+        toggleTerminal={() => {}}
+        openSessionSummary={() => {}}
+        tasksOpen={false}
+      />
+    </LocaleProvider>,
+  );
+  await flushTimers();
+});
+
+const trigger = rootElement.querySelector<HTMLButtonElement>('button[aria-haspopup="menu"]');
+if (!trigger) throw new Error("missing more-menu trigger");
+
+await act(async () => {
+  trigger.click();
+  await flushTimers();
+});
+await waitFor("lazy menu content", () => rootElement.querySelector('[role="menu"]') !== null);
+
+let menu = rootElement.querySelector<HTMLElement>('.topicbar__more-menu[role="menu"]');
+if (!menu) throw new Error("missing more menu");
+let items = directMenuItems(menu);
+ok(document.activeElement === items[0], "opening the menu moves focus to the first action");
+
+await act(async () => {
+  press(items[0]!, "ArrowDown");
+});
+ok(document.activeElement === items[1], "ArrowDown advances focus to the next action");
+
+await act(async () => {
+  press(items[1]!, "End");
+});
+ok(document.activeElement === items[items.length - 1], "End moves focus to the final action");
+
+await act(async () => {
+  press(items[items.length - 1]!, "Home");
+});
+ok(document.activeElement === items[0], "Home returns focus to the first action");
+
+await act(async () => {
+  items[1]?.focus();
+  press(items[1]!, "ArrowRight");
+  await flushTimers();
+});
+const exportMenu = rootElement.querySelector<HTMLElement>('.topicbar__more-export-menu[role="menu"]');
+if (!exportMenu) throw new Error("missing export submenu");
+const exportItems = directMenuItems(exportMenu);
+ok(document.activeElement === exportItems[0], "ArrowRight opens the export submenu and focuses its first action");
+
+await act(async () => {
+  press(exportItems[0]!, "ArrowDown");
+});
+ok(document.activeElement === exportItems[1], "submenu ArrowDown stays within the submenu");
+
+await act(async () => {
+  press(exportItems[1]!, "ArrowLeft");
+  await flushTimers();
+});
+ok(rootElement.querySelector(".topicbar__more-export-menu") === null, "ArrowLeft closes the export submenu");
+ok(document.activeElement === items[1], "closing the export submenu restores focus to its trigger");
+
+await act(async () => {
+  press(items[1]!, "Escape");
+  await flushTimers();
+});
+ok(rootElement.querySelector(".topicbar__more-menu") === null, "Escape closes the main menu");
+ok(document.activeElement === trigger, "closing the main menu restores focus to the More trigger");
+
+await act(async () => {
+  press(trigger, "ArrowUp");
+  await flushTimers();
+});
+await waitFor("keyboard-opened menu", () => rootElement.querySelector(".topicbar__more-menu") !== null);
+menu = rootElement.querySelector<HTMLElement>('.topicbar__more-menu[role="menu"]');
+if (!menu) throw new Error("missing keyboard-opened menu");
+items = directMenuItems(menu);
+ok(document.activeElement === items[items.length - 1], "ArrowUp on the trigger opens the menu at its final action");
+
+await act(async () => {
+  root.unmount();
+  await flushTimers();
+});
+
+console.log(`\ntopicbar more menu: ${passed} passed, ${failed} failed`);
+if (failed > 0) process.exit(1);
@@ -1,28 +1,9 @@
 // Run: tsx src/__tests__/workspace-changes-errors.test.tsx

-import { JSDOM } from "jsdom";
-import { registerHooks } from "node:module";
-import React from "react";
 import { act } from "react";
-import { createRoot } from "react-dom/client";
 import { workspaceFileIcon } from "../components/WorkspaceFileIcon";
-import { WorkspacePanel } from "../components/WorkspacePanel";
-import { LocaleProvider } from "../lib/i18n";
-import { resetWorkspaceTreeMemoryForTests } from "../lib/workspaceTreeMemory";
-import type { AppBindings } from "../lib/bridge";
-import type { DirEntry, FilePreview, GitCommitView, WireCompletionSummary, WorkspaceChangeDetailView, WorkspaceChangesView } from "../lib/types";
-
-// Markdown previews lazy-load MarkdownRenderer, whose KaTeX stylesheet belongs
-// to the same production chunk. Node's tsx loader has no CSS module support,
-// so map stylesheet imports to the existing empty asset stub in this DOM test.
-registerHooks({
-  resolve(specifier, context, nextResolve) {
-    if (specifier.endsWith(".css")) {
-      return nextResolve("./asset-stub-for-tests.ts", { ...context, parentURL: import.meta.url });
-    }
-    return nextResolve(specifier, context);
-  },
-});
+import type { DirEntry, FilePreview, WorkspaceChangeDetailView, WorkspaceChangesView } from "../lib/types";
+import { flushPromises, renderFilesWorkspace, renderWorkspace, waitFor } from "./workspace-panel-test-harness";

 let passed = 0;
 let failed = 0;
@@ -37,169 +18,6 @@ function ok(value: boolean, label: string) {
  }
 }

-function flushPromises(): Promise<void> {
-  return new Promise((resolve) => setTimeout(resolve, 0));
-}
-
-async function waitFor(label: string, predicate: () => boolean) {
-  for (let attempt = 0; attempt < 20; attempt += 1) {
-    await act(async () => {
-      await flushPromises();
-    });
-    if (predicate()) return;
-  }
-  throw new Error(`timed out waiting for ${label}`);
-}
-
-class TestResizeObserver {
-  observe() {}
-  unobserve() {}
-  disconnect() {}
-}
-
-function installDom() {
-  const dom = new JSDOM("<!doctype html><html><body><div id=\"root\"></div></body></html>", {
-    pretendToBeVisual: true,
-    url: "http://localhost/",
-  });
-  (globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
-  globalThis.window = dom.window as unknown as Window & typeof globalThis;
-  globalThis.document = dom.window.document;
-  Object.defineProperty(globalThis, "navigator", { configurable: true, value: dom.window.navigator });
-  globalThis.Node = dom.window.Node;
-  globalThis.Element = dom.window.Element;
-  globalThis.HTMLElement = dom.window.HTMLElement;
-  globalThis.Event = dom.window.Event;
-  globalThis.CustomEvent = dom.window.CustomEvent;
-  globalThis.KeyboardEvent = dom.window.KeyboardEvent;
-  globalThis.MouseEvent = dom.window.MouseEvent;
-  globalThis.PointerEvent = dom.window.MouseEvent as unknown as typeof PointerEvent;
-  globalThis.MutationObserver = dom.window.MutationObserver;
-  globalThis.ResizeObserver = TestResizeObserver;
-  dom.window.ResizeObserver = TestResizeObserver;
-  globalThis.localStorage = dom.window.localStorage;
-  globalThis.requestAnimationFrame = dom.window.requestAnimationFrame.bind(dom.window);
-  globalThis.cancelAnimationFrame = dom.window.cancelAnimationFrame.bind(dom.window);
-  (dom.window.HTMLElement.prototype as unknown as { attachEvent: () => void }).attachEvent = () => {};
-  (dom.window.HTMLElement.prototype as unknown as { detachEvent: () => void }).detachEvent = () => {};
-  Object.defineProperty(dom.window.HTMLElement.prototype, "scrollIntoView", { configurable: true, value: () => {} });
-  Object.defineProperty(dom.window.HTMLElement.prototype, "offsetWidth", {
-    configurable: true,
-    get: () => 320,
-  });
-  Object.defineProperty(dom.window.HTMLElement.prototype, "offsetHeight", {
-    configurable: true,
-    get: function offsetHeight(this: HTMLElement) {
-      return this.classList.contains("workspace-tree") ? 300 : this.dataset.index ? 24 : 0;
-    },
-  });
-  Object.defineProperty(dom.window.HTMLElement.prototype, "getBoundingClientRect", {
-    configurable: true,
-    value: function getBoundingClientRect(this: HTMLElement) {
-      const width = 320;
-      const height = this.classList.contains("workspace-tree") ? 300 : this.dataset.index ? 24 : 0;
-      return {
-        x: 0,
-        y: 0,
-        top: 0,
-        left: 0,
-        right: width,
-        bottom: height,
-        width,
-        height,
-        toJSON: () => ({}),
-      } as DOMRect;
-    },
-  });
-  return dom;
-}
-
-async function renderWorkspace(
-  changes: WorkspaceChangesView,
-  options: { creationMode?: boolean; history?: GitCommitView[]; detail?: WorkspaceChangeDetailView; completionSummary?: WireCompletionSummary } = {},
-) {
-  resetWorkspaceTreeMemoryForTests();
-  const dom = installDom();
-  window.go = {
-    main: {
-      App: {
-        ListDirForTab: async () => [],
-        WorkspaceGitHistory: async () => options.history ?? [],
-        WorkspaceChanges: async () => changes,
-        WorkspaceChangeDetail: async () => options.detail ?? {},
-        ReadFileForTab: async (_tabID, path) => ({ path, body: "", size: 0, truncated: false, binary: false }),
-      } as Partial<AppBindings> as AppBindings,
-    },
-  };
-  const rootEl = document.getElementById("root");
-  if (!rootEl) throw new Error("missing root");
-  const root = createRoot(rootEl);
-  await act(async () => {
-    root.render(
-      <LocaleProvider>
-        <WorkspacePanel
-          open
-          tabId="tab-a"
-          cwd="/repo"
-          maximized={false}
-          initialViewMode="changed"
-          creationMode={options.creationMode}
-          completionSummary={options.completionSummary}
-          onClose={() => {}}
-          onToggleMaximized={() => {}}
-        />
-      </LocaleProvider>,
-    );
-    await flushPromises();
-  });
-  await waitFor("workspace changes", () => Boolean(document.querySelector(".workspace-preview__body")));
-  return { dom, root };
-}
-
-async function renderFilesWorkspace(methods: Partial<AppBindings>, props: Partial<Parameters<typeof WorkspacePanel>[0]> = {}) {
-  resetWorkspaceTreeMemoryForTests();
-  const dom = installDom();
-  window.go = {
-    main: {
-      App: {
-        ListDirForTab: async () => [],
-        SearchFileRefsForTab: async () => [],
-        WorkspaceGitHistory: async () => [],
-        WorkspaceChanges: async () => ({ files: [], gitAvailable: true }),
-        WorkspaceChangeDetail: async () => ({}),
-        ReadFileForTab: async (_tabID, path) => ({ path, body: "", size: 0, truncated: false, binary: false }),
-        ...methods,
-      } as Partial<AppBindings> as AppBindings,
-    },
-  };
-  const rootEl = document.getElementById("root");
-  if (!rootEl) throw new Error("missing root");
-  const root = createRoot(rootEl);
-  let currentProps: Parameters<typeof WorkspacePanel>[0] = {
-    open: true,
-    tabId: "tab-a",
-    cwd: "/repo",
-    maximized: false,
-    initialViewMode: "files",
-    onClose: () => {},
-    onToggleMaximized: () => {},
-    ...props,
-  };
-  const rerender = async (nextProps: Partial<Parameters<typeof WorkspacePanel>[0]> = {}) => {
-    currentProps = { ...currentProps, ...nextProps };
-    await act(async () => {
-      root.render(
-        <LocaleProvider>
-          <WorkspacePanel {...currentProps} />
-        </LocaleProvider>,
-      );
-      await flushPromises();
-    });
-  };
-  await rerender();
-  return { dom, root, rerender };
-}
-
 console.log("\nworkspace changes git errors");

 {
@@ -19,6 +19,10 @@ let failed = 0;
 const testDir = dirname(fileURLToPath(import.meta.url));
 const appSource = readFileSync(resolve(testDir, "../App.tsx"), "utf8");
 const stylesSource = readFileSync(resolve(testDir, "../styles.css"), "utf8");
+const moreMenuSource = [
+  readFileSync(resolve(testDir, "../components/TopicbarMoreMenu.tsx"), "utf8"),
+  readFileSync(resolve(testDir, "../components/TopicbarMoreMenuContent.tsx"), "utf8"),
+].join("\n");
 const terminalPanelSource = readFileSync(resolve(testDir, "../components/TerminalPanel.tsx"), "utf8");
 const terminalViewSource = readFileSync(resolve(testDir, "../components/TerminalView.tsx"), "utf8");
 const terminalRailSource = readFileSync(resolve(testDir, "../components/TerminalSessionRail.tsx"), "utf8");
@@ -160,7 +164,7 @@ eq(terminalMaxHeight(180), 120, "terminal maximum never falls below the accessib
 eq(clampTerminalHeight(680, 480), 240, "restored terminal height clamps after the window shrinks");
 eq(clampTerminalHeight(80, 720), 120, "terminal height clamps to its minimum");
 eq(
-  /const closeWorkspacePanel = useCallback\(\(\) => \{[\s\S]*?setLiveWorkspacePanelRenderWidth\(null\);[\s\S]*?setWorkspacePanelOpen\(false\);[\s\S]*?saveWorkspacePanelOpen\(false\);/.test(appSource),
+  /const closeWorkspacePanel = useCallback\(\(\) => \{[\s\S]*?setLiveWorkspacePanelRenderWidth\(null\);[\s\S]*?setWorkspacePanelOpen\(false\);[\s\S]*?saveWorkspacePanelOpen\(false, activeWorkspaceRoot\);/.test(appSource),
  true,
  "closing the dock clears the transient render width, hides the panel, and persists the collapsed preference",
 );
@@ -177,7 +181,7 @@ eq(
  "workspace resize has one guarded finish path for capture loss, blur, cancellation, and unmount",
 );
 eq(
-  /setWorkspacePanelOpen\(true\);[\s\S]*?saveWorkspacePanelOpen\(true\);/.test(appSource),
+  /setWorkspacePanelOpen\(true\);[\s\S]*?saveWorkspacePanelOpen\(true, activeWorkspaceRoot\);/.test(appSource),
  true,
  "opening the dock persists the expanded preference for the next launch",
 );
@@ -253,7 +257,8 @@ const workspaceDockTabsSource = appSource.match(/<div className="workbench-dock_
 eq(
  workspaceDockTabsSource.length > 0
    && !/rightDock\.terminal|terminalPanelOpen|toggleTerminalPanel/.test(workspaceDockTabsSource)
-    && /className="topicbar__action-btn topicbar__action-btn--icon topicbar__action-btn--utility"[\s\S]*?aria-label=\{t\("rightDock\.terminal"\)\}[\s\S]*?onClick=\{toggleTerminalPanel\}/.test(appSource),
+    && /<TopicbarMoreMenu[\s\S]*?toggleTerminal=\{toggleTerminalPanel\}/.test(appSource)
+    && /className="topicbar__menu-item"[\s\S]*?closeAndRun\(toggleTerminal\)[\s\S]*?t\("rightDock\.terminal"\)/.test(moreMenuSource),
  true,
  "workspace dock omits the terminal view while the topic bar keeps the terminal drawer action",
 );
@@ -324,11 +329,11 @@ eq(
  "terminal and xterm remain in a lazy chunk",
 );
 eq(
-  /onPointerEnter=\{prefetchTerminalPanel\}/.test(appSource)
-    && /onFocus=\{prefetchTerminalPanel\}/.test(appSource)
+  /onPointerEnter=\{prefetchTerminal\}/.test(moreMenuSource)
+    && /onFocus=\{prefetchTerminal\}/.test(moreMenuSource)
    && /void import\("\.\.\/components\/TerminalPanel"\)/.test(terminalLifecycleSource),
  true,
-  "pointer and keyboard intent prefetch the terminal chunk before opening",
+  "pointer and keyboard intent prefetch the terminal chunk before opening (More menu)",
 );
 eq(
  /useWarmTerminalPanel\(terminalPanelOpen, terminalResizing\)/.test(appSource)
@@ -370,5 +375,45 @@ eq(
  "closing a warm terminal removes portaled selection controls",
 );

+// C1: the chat pane keeps its 400px floor no matter how wide the dock is
+// dragged — the dock's available width is viewport minus sidebar minus the
+// 400px chat minimum minus the resizer, so chat can never be squeezed below it.
+const chatFloorDock = availableWorkspacePanelWidth({
+  viewportWidth: 1000,
+  sidebarCollapsed: false,
+  sidebarWidth: SIDEBAR_WIDTH,
+  chatMinWidth: CHAT_MIN_WIDTH,
+  resizerWidth: RESIZER_WIDTH,
+});
+eq(
+  chatFloorDock + SIDEBAR_WIDTH + CHAT_MIN_WIDTH + RESIZER_WIDTH <= 1000,
+  true,
+  "C1: dock width never consumes the chat 400px floor (chat stays readable)",
+);
+// Sanity: with a wide viewport the dock gets more room, but the chat floor is
+// still reserved — chat is never the thing that shrinks.
+const wideDock = availableWorkspacePanelWidth({
+  viewportWidth: 1600,
+  sidebarCollapsed: false,
+  sidebarWidth: SIDEBAR_WIDTH,
+  chatMinWidth: CHAT_MIN_WIDTH,
+  resizerWidth: RESIZER_WIDTH,
+});
+eq(wideDock > chatFloorDock, true, "C1: wider viewport gives the dock more room, chat floor untouched");
+
+// C3: switching dock tabs (context/files/changed) must never resize the dock —
+// the preferred width is a single source (rightDockTreeWidth), not a
+// detail-dependent ternary that would jump the sidebar per tab.
+eq(
+  /const preferredWorkspacePanelWidth = rightDockTreeWidth;/.test(appSource),
+  true,
+  "C3: preferredWorkspacePanelWidth is the single tree width (no detail ternary)",
+);
+eq(
+  /const preferredWorkspacePanelWidth = rightDockDetailActive \? rightDockPreviewWidth : rightDockTreeWidth;/.test(appSource),
+  false,
+  "C3: no preview-width dual system that would resize the sidebar on tab switch",
+);
+
 console.log(`\n${passed} passed, ${failed} failed, ${passed + failed} total`);
 if (failed > 0) process.exit(1);
@@ -0,0 +1,65 @@
+// Run: tsx src/__tests__/workspace-panel-open-migration.test.ts
+// zk-ge C14 兼容性：项目级 dock 开合 key 缺失时回退旧全局 key，升级不翻转用户选择
+
+import { JSDOM } from "jsdom";
+
+let passed = 0;
+let failed = 0;
+
+function ok(value: boolean, label: string) {
+  if (value) {
+    process.stdout.write(`  PASS  ${label}\n`);
+    passed += 1;
+  } else {
+    process.stdout.write(`  FAIL  ${label}\n`);
+    failed += 1;
+  }
+}
+
+function installLocalStorage(seed: Record<string, string>) {
+  const dom = new JSDOM("<!doctype html><html><body></body></html>", { url: "http://localhost/" });
+  globalThis.window = dom.window;
+  globalThis.localStorage = dom.window.localStorage;
+  for (const [key, value] of Object.entries(seed)) {
+    dom.window.localStorage.setItem(key, value);
+  }
+  return dom;
+}
+
+// 动态 import（依赖 window/localStorage 已就绪）
+async function loadModule() {
+  return await import("../store/layout");
+}
+
+console.log("\nworkspace dock-open legacy key migration (CLAIM.PERSIST.014)");
+
+{
+  // 场景 1：项目 key 缺失 + 旧全局 key = 关闭("0") → 首次打开项目应保持关闭
+  installLocalStorage({ "reasonix.workspacePanel.open": "0" });
+  const { loadWorkspacePanelOpen } = await loadModule();
+  ok(loadWorkspacePanelOpen("project-a") === false, "project key missing + legacy global closed => stays closed");
+}
+
+{
+  // 场景 2：项目 key 缺失 + 旧全局 key = 打开("1") → 首次打开项目应打开
+  installLocalStorage({ "reasonix.workspacePanel.open": "1" });
+  const { loadWorkspacePanelOpen } = await loadModule();
+  ok(loadWorkspacePanelOpen("project-b") === true, "project key missing + legacy global open => stays open");
+}
+
+{
+  // 场景 3：项目 key 存在（优先于旧全局 key）
+  installLocalStorage({ "reasonix.workspacePanel.open": "0", "reasonix.workspacePanel.open.project-c": "1" });
+  const { loadWorkspacePanelOpen } = await loadModule();
+  ok(loadWorkspacePanelOpen("project-c") === true, "project key present wins over legacy global");
+}
+
+{
+  // 场景 4：项目 key 和旧全局 key 都缺失 → 默认打开
+  installLocalStorage({});
+  const { loadWorkspacePanelOpen } = await loadModule();
+  ok(loadWorkspacePanelOpen("project-d") === true, "neither key present => default open");
+}
+
+console.log(`\nworkspace dock-open migration: ${passed} passed, ${failed} failed`);
+if (failed > 0) process.exit(1);
@@ -0,0 +1,181 @@
+import { JSDOM } from "jsdom";
+import { registerHooks } from "node:module";
+import React, { act } from "react";
+import { createRoot } from "react-dom/client";
+import { WorkspacePanel } from "../components/WorkspacePanel";
+import type { AppBindings } from "../lib/bridge";
+import { LocaleProvider } from "../lib/i18n";
+import type { GitCommitView, WireCompletionSummary, WorkspaceChangeDetailView, WorkspaceChangesView } from "../lib/types";
+import { resetWorkspaceTreeMemoryForTests } from "../lib/workspaceTreeMemory";
+
+registerHooks({
+  resolve(specifier, context, nextResolve) {
+    if (specifier.endsWith(".css")) {
+      return nextResolve("./asset-stub-for-tests.ts", { ...context, parentURL: import.meta.url });
+    }
+    return nextResolve(specifier, context);
+  },
+});
+
+class TestResizeObserver {
+  observe() {}
+  unobserve() {}
+  disconnect() {}
+}
+
+export function flushPromises(): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, 0));
+}
+
+export async function waitFor(label: string, predicate: () => boolean) {
+  for (let attempt = 0; attempt < 20; attempt += 1) {
+    await act(async () => {
+      await flushPromises();
+    });
+    if (predicate()) return;
+  }
+  throw new Error(`timed out waiting for ${label}`);
+}
+
+function installDom() {
+  const dom = new JSDOM("<!doctype html><html><body><div id=\"root\"></div></body></html>", {
+    pretendToBeVisual: true,
+    url: "http://localhost/",
+  });
+  (globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+  globalThis.window = dom.window as unknown as Window & typeof globalThis;
+  globalThis.document = dom.window.document;
+  Object.defineProperty(globalThis, "navigator", { configurable: true, value: dom.window.navigator });
+  globalThis.Node = dom.window.Node;
+  globalThis.Element = dom.window.Element;
+  globalThis.HTMLElement = dom.window.HTMLElement;
+  globalThis.Event = dom.window.Event;
+  globalThis.CustomEvent = dom.window.CustomEvent;
+  globalThis.KeyboardEvent = dom.window.KeyboardEvent;
+  globalThis.MouseEvent = dom.window.MouseEvent;
+  globalThis.PointerEvent = dom.window.MouseEvent as unknown as typeof PointerEvent;
+  globalThis.MutationObserver = dom.window.MutationObserver;
+  globalThis.ResizeObserver = TestResizeObserver;
+  dom.window.ResizeObserver = TestResizeObserver;
+  globalThis.localStorage = dom.window.localStorage;
+  globalThis.requestAnimationFrame = dom.window.requestAnimationFrame.bind(dom.window);
+  globalThis.cancelAnimationFrame = dom.window.cancelAnimationFrame.bind(dom.window);
+  (dom.window.HTMLElement.prototype as unknown as { attachEvent: () => void }).attachEvent = () => {};
+  (dom.window.HTMLElement.prototype as unknown as { detachEvent: () => void }).detachEvent = () => {};
+  Object.defineProperty(dom.window.HTMLElement.prototype, "scrollIntoView", { configurable: true, value: () => {} });
+  Object.defineProperty(dom.window.HTMLElement.prototype, "offsetWidth", {
+    configurable: true,
+    get: () => 320,
+  });
+  Object.defineProperty(dom.window.HTMLElement.prototype, "offsetHeight", {
+    configurable: true,
+    get: function offsetHeight(this: HTMLElement) {
+      return this.classList.contains("workspace-tree") ? 300 : this.dataset.index ? 24 : 0;
+    },
+  });
+  Object.defineProperty(dom.window.HTMLElement.prototype, "getBoundingClientRect", {
+    configurable: true,
+    value: function getBoundingClientRect(this: HTMLElement) {
+      const width = 320;
+      const height = this.classList.contains("workspace-tree") ? 300 : this.dataset.index ? 24 : 0;
+      return {
+        x: 0,
+        y: 0,
+        top: 0,
+        left: 0,
+        right: width,
+        bottom: height,
+        width,
+        height,
+        toJSON: () => ({}),
+      } as DOMRect;
+    },
+  });
+  return dom;
+}
+
+export async function renderWorkspace(
+  changes: WorkspaceChangesView,
+  options: { creationMode?: boolean; history?: GitCommitView[]; detail?: WorkspaceChangeDetailView; completionSummary?: WireCompletionSummary } = {},
+) {
+  resetWorkspaceTreeMemoryForTests();
+  const dom = installDom();
+  window.go = {
+    main: {
+      App: {
+        ListDirForTab: async () => [],
+        WorkspaceGitHistory: async () => options.history ?? [],
+        WorkspaceChanges: async () => changes,
+        WorkspaceChangeDetail: async () => options.detail ?? {},
+        ReadFileForTab: async (_tabID, path) => ({ path, body: "", size: 0, truncated: false, binary: false }),
+      } as Partial<AppBindings> as AppBindings,
+    },
+  };
+  const rootEl = document.getElementById("root");
+  if (!rootEl) throw new Error("missing root");
+  const root = createRoot(rootEl);
+  await act(async () => {
+    root.render(
+      <LocaleProvider>
+        <WorkspacePanel
+          open
+          tabId="tab-a"
+          cwd="/repo"
+          maximized={false}
+          initialViewMode="changed"
+          creationMode={options.creationMode}
+          completionSummary={options.completionSummary}
+          onClose={() => {}}
+          onToggleMaximized={() => {}}
+        />
+      </LocaleProvider>,
+    );
+    await flushPromises();
+  });
+  await waitFor("workspace changes", () => Boolean(document.querySelector(".workspace-preview__body")));
+  return { dom, root };
+}
+
+export async function renderFilesWorkspace(methods: Partial<AppBindings>, props: Partial<Parameters<typeof WorkspacePanel>[0]> = {}) {
+  resetWorkspaceTreeMemoryForTests();
+  const dom = installDom();
+  window.go = {
+    main: {
+      App: {
+        ListDirForTab: async () => [],
+        SearchFileRefsForTab: async () => [],
+        WorkspaceGitHistory: async () => [],
+        WorkspaceChanges: async () => ({ files: [], gitAvailable: true }),
+        WorkspaceChangeDetail: async () => ({}),
+        ReadFileForTab: async (_tabID, path) => ({ path, body: "", size: 0, truncated: false, binary: false }),
+        ...methods,
+      } as Partial<AppBindings> as AppBindings,
+    },
+  };
+  const rootEl = document.getElementById("root");
+  if (!rootEl) throw new Error("missing root");
+  const root = createRoot(rootEl);
+  let currentProps: Parameters<typeof WorkspacePanel>[0] = {
+    open: true,
+    tabId: "tab-a",
+    cwd: "/repo",
+    maximized: false,
+    initialViewMode: "files",
+    onClose: () => {},
+    onToggleMaximized: () => {},
+    ...props,
+  };
+  const rerender = async (nextProps: Partial<Parameters<typeof WorkspacePanel>[0]> = {}) => {
+    currentProps = { ...currentProps, ...nextProps };
+    await act(async () => {
+      root.render(
+        <LocaleProvider>
+          <WorkspacePanel {...currentProps} />
+        </LocaleProvider>,
+      );
+      await flushPromises();
+    });
+  };
+  await rerender();
+  return { dom, root, rerender };
+}
@@ -119,22 +119,22 @@ eq(
 );
 eq(
  finalDeclaration(".workspace-panel--with-tree-rail:not(.workspace-panel--tree-hidden)", "grid-template-columns"),
-  "var(--workspace-tree-rail-width) var(--workspace-tree-width) minmax(var(--workspace-preview-min-width), 1fr)",
-  "split mode keeps a narrow tree toggle rail beside the file tree",
+  "var(--workspace-tree-rail-width) minmax(var(--workspace-preview-min-width), 1fr) var(--workspace-tree-width)",
+  "split mode keeps a narrow tree toggle rail beside the file tree (preview left, tree right per user preference)",
 );
-eq(finalDeclaration(".workspace-panel--with-tree-rail:not(.workspace-panel--tree-hidden) .workspace-files", "grid-column"), "2", "file tree sits beside the rail");
-eq(finalDeclaration(".workspace-panel--with-tree-rail:not(.workspace-panel--tree-hidden) .workspace-preview", "grid-column"), "3", "preview sits after rail and tree");
+eq(finalDeclaration(".workspace-panel--with-tree-rail:not(.workspace-panel--tree-hidden) .workspace-files", "grid-column"), "3", "file tree sits at the far right after the preview");
+eq(finalDeclaration(".workspace-panel--with-tree-rail:not(.workspace-panel--tree-hidden) .workspace-preview", "grid-column"), "2", "preview sits after the rail, before the tree");
 eq(
  finalDeclaration(".workspace-panel--with-tree-rail .workspace-tree-resizer", "left"),
-  "calc(var(--workspace-tree-rail-width) + var(--workspace-tree-width) - 4px)",
-  "tree resizer accounts for the persistent rail",
+  "calc(100% - var(--workspace-tree-width) - 4px)",
+  "tree resizer sits at the tree's left edge (tree is on the right)",
 );
 eq(
  finalDeclaration(".workspace-panel--tree-hidden", "grid-template-columns"),
-  "var(--workspace-tree-rail-width) minmax(0, 1fr)",
-  "preview-only mode keeps a narrow tree toggle rail",
+  "minmax(0, 1fr)",
+  "preview-only mode drops the tree rail",
 );
-eq(finalDeclaration(".workspace-panel--tree-hidden .workspace-preview", "grid-column"), "2", "preview sits beside the rail");
+eq(finalDeclaration(".workspace-panel--tree-hidden .workspace-preview", "grid-column"), "1", "preview fills the panel when the tree is hidden");
 eq(
  /const filePreviewLimit = 2 \* 1024 \* 1024/.test(appGo),
  true,
@@ -0,0 +1,165 @@
+// Run: tsx src/__tests__/workspace-resize-interaction.test.tsx
+
+import { JSDOM } from "jsdom";
+import React from "react";
+import { act } from "react";
+import { createRoot } from "react-dom/client";
+import { WorkspacePanel } from "../components/WorkspacePanel";
+import type { AppBindings } from "../lib/bridge";
+import { LocaleProvider } from "../lib/i18n";
+import { resetWorkspaceTreeMemoryForTests } from "../lib/workspaceTreeMemory";
+
+let passed = 0;
+let failed = 0;
+
+function eq<T>(actual: T, expected: T, label: string) {
+  if (Object.is(actual, expected)) {
+    process.stdout.write(`  PASS  ${label}\n`);
+    passed += 1;
+  } else {
+    process.stdout.write(`  FAIL  ${label}: expected ${String(expected)}, got ${String(actual)}\n`);
+    failed += 1;
+  }
+}
+
+function flushTimers(): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, 0));
+}
+
+async function waitFor(label: string, predicate: () => boolean) {
+  for (let attempt = 0; attempt < 30; attempt += 1) {
+    await act(async () => {
+      await flushTimers();
+    });
+    if (predicate()) return;
+  }
+  throw new Error(`timed out waiting for ${label}`);
+}
+
+class TestResizeObserver {
+  observe() {}
+  unobserve() {}
+  disconnect() {}
+}
+
+const dom = new JSDOM("<!doctype html><html><body><div id=\"root\"></div></body></html>", {
+  pretendToBeVisual: true,
+  url: "http://localhost/",
+});
+(globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+globalThis.window = dom.window as unknown as Window & typeof globalThis;
+globalThis.document = dom.window.document;
+Object.defineProperty(dom.window.navigator, "language", { configurable: true, value: "en-US" });
+Object.defineProperty(globalThis, "navigator", { configurable: true, value: dom.window.navigator });
+globalThis.Node = dom.window.Node;
+globalThis.Element = dom.window.Element;
+globalThis.HTMLElement = dom.window.HTMLElement;
+globalThis.Event = dom.window.Event;
+globalThis.CustomEvent = dom.window.CustomEvent;
+globalThis.KeyboardEvent = dom.window.KeyboardEvent;
+globalThis.MouseEvent = dom.window.MouseEvent;
+globalThis.PointerEvent = dom.window.MouseEvent as unknown as typeof PointerEvent;
+globalThis.MutationObserver = dom.window.MutationObserver;
+globalThis.ResizeObserver = TestResizeObserver;
+dom.window.ResizeObserver = TestResizeObserver;
+globalThis.localStorage = dom.window.localStorage;
+globalThis.requestAnimationFrame = dom.window.requestAnimationFrame.bind(dom.window);
+globalThis.cancelAnimationFrame = dom.window.cancelAnimationFrame.bind(dom.window);
+Object.defineProperty(dom.window.HTMLElement.prototype, "scrollIntoView", { configurable: true, value: () => {} });
+Object.defineProperty(dom.window.HTMLElement.prototype, "offsetWidth", { configurable: true, get: () => 800 });
+Object.defineProperty(dom.window.HTMLElement.prototype, "offsetHeight", {
+  configurable: true,
+  get: function offsetHeight(this: HTMLElement) {
+    return this.classList.contains("workspace-tree") ? 300 : this.dataset.index ? 24 : 0;
+  },
+});
+Object.defineProperty(dom.window.HTMLElement.prototype, "getBoundingClientRect", {
+  configurable: true,
+  value: function getBoundingClientRect(this: HTMLElement) {
+    const width = 800;
+    const height = this.classList.contains("workspace-tree") ? 300 : this.dataset.index ? 24 : 0;
+    return { x: 100, y: 0, top: 0, left: 100, right: 900, bottom: height, width, height, toJSON: () => ({}) } as DOMRect;
+  },
+});
+
+console.log("\nworkspace right-side tree resize interaction");
+
+resetWorkspaceTreeMemoryForTests();
+window.go = {
+  main: {
+    App: {
+      ListDirForTab: async (_tabId, dir) => dir === "" ? [{ name: "app.ts", isDir: false }] : [],
+      SearchFileRefsForTab: async () => [],
+      WorkspaceGitHistory: async () => [],
+      WorkspaceChanges: async () => ({ files: [], gitAvailable: true }),
+      WorkspaceChangeDetail: async () => ({}),
+      ReadFileForTab: async (_tabId, path) => ({ path, body: "const value = 1;", size: 16, truncated: false, binary: false }),
+    } as Partial<AppBindings> as AppBindings,
+  },
+};
+
+const rootElement = document.getElementById("root");
+if (!rootElement) throw new Error("missing root");
+const root = createRoot(rootElement);
+await act(async () => {
+  root.render(
+    <LocaleProvider>
+      <WorkspacePanel
+        open
+        tabId="resize-tab"
+        cwd="/repo"
+        maximized={false}
+        panelWidth={800}
+        initialViewMode="files"
+        onClose={() => {}}
+        onToggleMaximized={() => {}}
+      />
+    </LocaleProvider>,
+  );
+  await flushTimers();
+});
+
+await waitFor("workspace file", () => document.querySelector('[data-workspace-path="app.ts"]') !== null);
+await act(async () => {
+  document.querySelector<HTMLButtonElement>('[data-workspace-path="app.ts"]')?.click();
+  await flushTimers();
+});
+await waitFor("tree separator", () => document.querySelector(".workspace-tree-resizer") !== null);
+
+const separator = document.querySelector<HTMLButtonElement>(".workspace-tree-resizer");
+if (!separator) throw new Error("missing tree separator");
+const initialWidth = Number(separator.getAttribute("aria-valuenow"));
+
+await act(async () => {
+  separator.dispatchEvent(new window.KeyboardEvent("keydown", { bubbles: true, cancelable: true, key: "ArrowRight" }));
+  await flushTimers();
+});
+eq(Number(separator.getAttribute("aria-valuenow")), initialWidth - 16, "ArrowRight moves the separator right and narrows the right-side tree");
+
+await act(async () => {
+  separator.dispatchEvent(new window.KeyboardEvent("keydown", { bubbles: true, cancelable: true, key: "ArrowLeft" }));
+  await flushTimers();
+});
+eq(Number(separator.getAttribute("aria-valuenow")), initialWidth, "ArrowLeft moves the separator left and widens the right-side tree");
+
+await act(async () => {
+  separator.dispatchEvent(new window.MouseEvent("pointerdown", { bubbles: true, cancelable: true, clientX: 600 }));
+  window.dispatchEvent(new window.MouseEvent("pointermove", { bubbles: true, clientX: 650 }));
+  window.dispatchEvent(new window.MouseEvent("pointerup", { bubbles: true, clientX: 650 }));
+  await flushTimers();
+});
+eq(Number(separator.getAttribute("aria-valuenow")), 250, "pointer position measures tree width from the panel's right edge");
+
+await act(async () => {
+  separator.dispatchEvent(new window.KeyboardEvent("keydown", { bubbles: true, cancelable: true, key: "End" }));
+  await flushTimers();
+});
+eq(Number(separator.getAttribute("aria-valuenow")), 616, "End preserves minimum space for the rail and preview");
+
+await act(async () => {
+  root.unmount();
+});
+dom.window.close();
+
+console.log(`\n${passed} passed, ${failed} failed, ${passed + failed} total`);
+if (failed > 0) process.exit(1);
@@ -0,0 +1,91 @@
+// Run: tsx src/__tests__/workspace-selection-isolation.test.tsx
+
+import { act } from "react";
+import { flushPromises, renderFilesWorkspace, waitFor } from "./workspace-panel-test-harness";
+
+let passed = 0;
+let failed = 0;
+
+function ok(value: boolean, label: string) {
+  if (value) {
+    process.stdout.write(`  PASS  ${label}\n`);
+    passed += 1;
+  } else {
+    process.stdout.write(`  FAIL  ${label}\n`);
+    failed += 1;
+  }
+}
+
+console.log("\nworkspace selection isolation");
+
+const changeDetailPaths: string[] = [];
+const { dom, root, rerender } = await renderFilesWorkspace({
+  ListDirForTab: async (_tabId, dir) => dir === "" ? [{ name: "notes.txt", isDir: false }] : [],
+  WorkspaceChanges: async () => ({
+    files: [{ path: "src/changed.ts", sources: ["git"], gitStatus: "M" }],
+    gitAvailable: true,
+  }),
+  WorkspaceChangeDetail: async (_tabId, path) => {
+    changeDetailPaths.push(path);
+    return { source: "git", diff: "changed diff" };
+  },
+  ReadFileForTab: async (_tabId, path) => ({ path, body: "file preview", size: 12, truncated: false, binary: false }),
+});
+
+await waitFor("files view entry", () => document.body.textContent?.includes("notes.txt") === true);
+await act(async () => {
+  document.querySelector<HTMLButtonElement>('[data-workspace-path="notes.txt"]')
+    ?.dispatchEvent(new window.MouseEvent("click", { bubbles: true }));
+  await flushPromises();
+});
+await waitFor("selected file preview", () => document.body.textContent?.includes("file preview") === true);
+
+await rerender({ initialViewMode: "changed" });
+await waitFor("changes overview", () => document.body.textContent?.includes("changed.ts") === true);
+ok(changeDetailPaths.length === 0, "entering Changes does not request diff detail for the Files selection");
+ok(document.querySelector(".workspace-panel--changed-overview") !== null, "entering Changes opens its overview instead of leaking the Files selection");
+
+await act(async () => {
+  document.querySelector<HTMLButtonElement>(".workspace-change")
+    ?.dispatchEvent(new window.MouseEvent("click", { bubbles: true }));
+  await flushPromises();
+});
+await waitFor("selected change detail", () => changeDetailPaths.includes("src/changed.ts"));
+
+await rerender({ initialViewMode: "files" });
+await waitFor("restored file preview", () => document.body.textContent?.includes("file preview") === true);
+ok(changeDetailPaths.every((path) => path === "src/changed.ts"), "Changes requests only its own selected path");
+ok(document.body.textContent?.includes("notes.txt") === true, "returning to Files restores the prior file selection after viewing a change");
+
+await rerender({
+  initialViewMode: "changed",
+  changeListRequest: {
+    id: 1,
+    changes: [{ key: "scoped-change", path: "src/changed.ts", meta: "M", time: "", detail: "changed" }],
+  },
+});
+await waitFor("scoped Changes list", () => document.body.textContent?.includes("Session changes") === true);
+await rerender({ initialViewMode: "files", changeListRequest: null });
+await waitFor("file preview after scoped Changes", () => document.body.textContent?.includes("file preview") === true);
+ok(document.body.textContent?.includes("notes.txt") === true, "scoped Changes requests preserve the Files preview state");
+
+await rerender({ initialViewMode: "changed" });
+await waitFor("change before scope switch", () => document.body.textContent?.includes("changed.ts") === true);
+await act(async () => {
+  document.querySelector<HTMLButtonElement>(".workspace-change")
+    ?.dispatchEvent(new window.MouseEvent("click", { bubbles: true }));
+  await flushPromises();
+});
+await waitFor("change selected before scope switch", () => changeDetailPaths.includes("src/changed.ts"));
+const callsBeforeScopeSwitch = changeDetailPaths.length;
+await rerender({ workspaceScopeKey: "other-session" });
+await waitFor("new scope Changes overview", () => document.querySelector(".workspace-panel--changed-overview") !== null);
+ok(changeDetailPaths.length === callsBeforeScopeSwitch, "workspace scope changes do not request the previous scope's selected change");
+
+await act(async () => {
+  root.unmount();
+});
+dom.window.close();
+
+console.log(`\n${passed} passed, ${failed} failed, ${passed + failed} total`);
+if (failed > 0) process.exit(1);
@@ -81,6 +81,34 @@ eq(
  "tree resize pointer clamps against the preview minimum after reserving the rail",
 );

+eq(
+  workspaceSplitTreeWidthFromPointer({
+    clientX: 650,
+    panelLeft: 100,
+    panelWidth: 800,
+    railWidth: TREE_RAIL_WIDTH,
+    treeMinWidth: TREE_MIN_WIDTH,
+    previewMinWidth: PREVIEW_MIN_WIDTH,
+    treeOnRight: true,
+  }),
+  250,
+  "right-side tree width is measured from the pointer to the panel's right edge",
+);
+
+eq(
+  workspaceSplitTreeWidthFromPointer({
+    clientX: 100,
+    panelLeft: 100,
+    panelWidth: 800,
+    railWidth: TREE_RAIL_WIDTH,
+    treeMinWidth: TREE_MIN_WIDTH,
+    previewMinWidth: PREVIEW_MIN_WIDTH,
+    treeOnRight: true,
+  }),
+  616,
+  "right-side tree maximum keeps space for the rail and preview",
+);
+
 eq(
  resolveWorkspaceSplitTreeWidth({
    mode: "even",
@@ -0,0 +1,250 @@
+// Run: tsx src/__tests__/workspace-tree-scroll-restore.test.tsx
+// zk-ge CLAIM.TREE.008: 切换 dock 标签（组件 unmount/remount）后文件树滚动位置恢复
+
+import { JSDOM } from "jsdom";
+import React from "react";
+import { act } from "react";
+import { createRoot } from "react-dom/client";
+import type { Root } from "react-dom/client";
+import { WorkspacePanel } from "../components/WorkspacePanel";
+import type { AppBindings } from "../lib/bridge";
+import { LocaleProvider } from "../lib/i18n";
+import { resetWorkspaceTreeMemoryForTests } from "../lib/workspaceTreeMemory";
+
+let passed = 0;
+let failed = 0;
+
+function ok(value: boolean, label: string) {
+  if (value) {
+    process.stdout.write(`  PASS  ${label}\n`);
+    passed += 1;
+  } else {
+    process.stdout.write(`  FAIL  ${label}\n`);
+    failed += 1;
+  }
+}
+
+function flushTimers(): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, 0));
+}
+
+async function waitFor(label: string, predicate: () => boolean) {
+  for (let attempt = 0; attempt < 30; attempt += 1) {
+    await act(async () => {
+      await flushTimers();
+    });
+    if (predicate()) return;
+  }
+  throw new Error(`timed out waiting for ${label}`);
+}
+
+class TestResizeObserver {
+  observe() {}
+  unobserve() {}
+  disconnect() {}
+}
+
+function installDom() {
+  const dom = new JSDOM("<!doctype html><html><body><div id=\"root\"></div></body></html>", {
+    pretendToBeVisual: true,
+    url: "http://localhost/",
+  });
+  (globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+  globalThis.window = dom.window as unknown as Window & typeof globalThis;
+  globalThis.document = dom.window.document;
+  Object.defineProperty(dom.window.navigator, "language", { configurable: true, value: "en-US" });
+  Object.defineProperty(globalThis, "navigator", { configurable: true, value: dom.window.navigator });
+  globalThis.Node = dom.window.Node;
+  globalThis.Element = dom.window.Element;
+  globalThis.HTMLElement = dom.window.HTMLElement;
+  globalThis.Event = dom.window.Event;
+  globalThis.CustomEvent = dom.window.CustomEvent;
+  globalThis.KeyboardEvent = dom.window.KeyboardEvent;
+  globalThis.MouseEvent = dom.window.MouseEvent;
+  globalThis.PointerEvent = dom.window.MouseEvent as unknown as typeof PointerEvent;
+  globalThis.MutationObserver = dom.window.MutationObserver;
+  globalThis.ResizeObserver = TestResizeObserver;
+  dom.window.ResizeObserver = TestResizeObserver;
+  globalThis.localStorage = dom.window.localStorage;
+  globalThis.requestAnimationFrame = dom.window.requestAnimationFrame.bind(dom.window);
+  globalThis.cancelAnimationFrame = dom.window.cancelAnimationFrame.bind(dom.window);
+  Object.defineProperty(dom.window.HTMLElement.prototype, "scrollIntoView", { configurable: true, value: () => {} });
+  Object.defineProperty(dom.window.HTMLElement.prototype, "offsetWidth", { configurable: true, get: () => 320 });
+  Object.defineProperty(dom.window.HTMLElement.prototype, "clientHeight", {
+    configurable: true,
+    get: function clientHeight(this: HTMLElement) {
+      return this.classList.contains("workspace-tree") ? 300 : 0;
+    },
+  });
+  Object.defineProperty(dom.window.HTMLElement.prototype, "scrollHeight", {
+    configurable: true,
+    get: function scrollHeight(this: HTMLElement) {
+      return this.classList.contains("workspace-tree") ? 40 * 24 : 0;
+    },
+  });
+  Object.defineProperty(dom.window.HTMLElement.prototype, "offsetHeight", {
+    configurable: true,
+    get: function offsetHeight(this: HTMLElement) {
+      return this.classList.contains("workspace-tree") ? 300 : this.dataset.index ? 24 : 0;
+    },
+  });
+  Object.defineProperty(dom.window.HTMLElement.prototype, "getBoundingClientRect", {
+    configurable: true,
+    value: function getBoundingClientRect(this: HTMLElement) {
+      const width = 320;
+      const height = this.classList.contains("workspace-tree") ? 300 : this.dataset.index ? 24 : 0;
+      return { x: 0, y: 0, top: 0, left: 0, right: width, bottom: height, width, height, toJSON: () => ({}) } as DOMRect;
+    },
+  });
+  Object.defineProperty(dom.window.HTMLElement.prototype, "scrollTo", {
+    configurable: true,
+    value: function scrollTo(this: HTMLElement, options?: ScrollToOptions | number) {
+      const requested = typeof options === "number" ? options : options?.top ?? 0;
+      const maximum = Math.max(0, this.scrollHeight - this.clientHeight);
+      this.scrollTop = Math.max(0, Math.min(maximum, requested));
+    },
+  });
+  return dom;
+}
+
+const MEMORY_KEY = "scroll-test\u0000/repo";
+
+function renderPanel(root: Root) {
+  return act(async () => {
+    root.render(
+      <LocaleProvider>
+        <WorkspacePanel
+          open
+          tabId="scroll-tab"
+          cwd="/repo"
+          workspaceMemoryKey={MEMORY_KEY}
+          maximized={false}
+          initialViewMode="files"
+          onClose={() => {}}
+          onToggleMaximized={() => {}}
+          onOpenInTerminal={() => {}}
+        />
+      </LocaleProvider>,
+    );
+    await flushTimers();
+  });
+}
+
+console.log("\nworkspace tree scroll restore (CLAIM.TREE.008)");
+
+resetWorkspaceTreeMemoryForTests();
+const dom = installDom();
+dom.window.localStorage.clear();
+const RESTORED_SCROLL_TOP = 200;
+dom.window.localStorage.setItem("reasonix.workspaceState.v2", JSON.stringify({
+  version: 2,
+  projects: [{
+    key: MEMORY_KEY,
+    state: {
+      openDirs: [""],
+      scrollTop: RESTORED_SCROLL_TOP,
+      updatedAt: Date.now(),
+    },
+  }],
+}));
+
+window.go = {
+  main: {
+    App: {
+      ListDirForTab: async (_tabId, dir) => {
+        if (dir === "") {
+          return Array.from({ length: 40 }, (_, i) => ({ name: `file-${i}.ts`, isDir: false }));
+        }
+        return [];
+      },
+      SearchFileRefsForTab: async () => [],
+      WorkspaceGitHistory: async () => [],
+      WorkspaceChanges: async () => ({ files: [], gitAvailable: true }),
+      WorkspaceChangeDetail: async () => ({}),
+      ReadFileForTab: async (_tabId, path) => ({ path, body: "", size: 0, truncated: false, binary: false }),
+      ResolveWorkspacePathForTab: async (_tabId, path) => `/repo/${path}`,
+      RevealWorkspacePathForTab: async () => {},
+      OpenWorkspacePathForTab: async () => {},
+    } as Partial<AppBindings> as AppBindings,
+  },
+};
+
+const rootElement = document.getElementById("root");
+if (!rootElement) throw new Error("missing root");
+const root = createRoot(rootElement);
+
+// Phase 1: mount from a persisted deep offset and verify the virtualizer writes
+// that offset into a genuinely scrollable DOM fixture.
+await renderPanel(root);
+await waitFor("workspace rows render", () => document.querySelectorAll(".workspace-tree__row").length > 0);
+
+const treeEl = document.querySelector<HTMLElement>(".workspace-tree");
+if (!treeEl) throw new Error("missing workspace-tree element");
+ok(treeEl.scrollHeight > treeEl.clientHeight, "fixture has a real scrollable extent");
+await waitFor("persisted tree offset restore", () => treeEl.scrollTop === RESTORED_SCROLL_TOP);
+ok(treeEl.scrollTop === RESTORED_SCROLL_TOP, "initial mount restores the persisted DOM scroll offset");
+
+// Scroll position should have been persisted to the upstream per-project
+// workspace state envelope (reasonix.workspaceState.v2).
+function persistedScrollTop(): number | null {
+  const raw = dom.window.localStorage.getItem("reasonix.workspaceState.v2");
+  if (!raw) return null;
+  try {
+    const parsed = JSON.parse(raw) as { projects?: Array<{ key: string; state: { scrollTop?: number } }> };
+    const project = parsed.projects?.find((entry) => entry.key === MEMORY_KEY);
+    return typeof project?.state?.scrollTop === "number" ? project.state.scrollTop : null;
+  } catch {
+    return null;
+  }
+}
+
+ok(persistedScrollTop() === RESTORED_SCROLL_TOP, "restoration preserves the persisted localStorage offset");
+
+// Phase 2: unmount (simulates switching from 文件 to 概览 dock tab)
+await act(async () => {
+  root.render(<></>);
+  await flushTimers();
+});
+
+// Phase 3: remount (simulates switching back to 文件)
+await renderPanel(root);
+await waitFor("workspace rows re-render", () => document.querySelectorAll(".workspace-tree__row").length > 0);
+
+const treeEl2 = document.querySelector<HTMLElement>(".workspace-tree");
+if (!treeEl2) throw new Error("missing workspace-tree element after remount");
+
+// The persisted value must survive the remount — verify the workspace memory
+// still holds it (this isolates persistence loss from virtualizer restore).
+ok(persistedScrollTop() === RESTORED_SCROLL_TOP, "persisted scroll offset survives remount in localStorage");
+
+// Remount must re-render the tree rows (otherwise the restore effect's
+// treeRows.length guard never passes).
+const rowsAfterRemount = document.querySelectorAll(".workspace-tree__row").length;
+ok(rowsAfterRemount > 0, `tree rows re-render after remount (got ${rowsAfterRemount})`);
+
+await waitFor("remounted tree DOM restore", () => treeEl2.scrollTop === RESTORED_SCROLL_TOP);
+ok(treeEl2.scrollTop === RESTORED_SCROLL_TOP, "dock-tab remount restores the actual DOM scroll offset");
+
+// Phase 4: switch to the "changed" view via the tab button, then back to
+// "files". The pending scroll restore must be reset on viewMode change — the
+// saved offset belongs to the previous mode's tree and re-applying it to a
+// shorter list (files -> changed) would scroll past the end and leave a blank
+// band at the top. We assert the panel still renders rows after the round
+// trip; the reset itself is what makes that render coherent.
+const tabs = document.querySelectorAll(".workspace-files__tab");
+ok(tabs.length >= 2, "files and changed view tabs render in the fixture");
+if (tabs.length >= 2) {
+  await act(async () => {
+    (tabs[1] as HTMLElement).click();
+    await flushTimers();
+  });
+  await act(async () => {
+    (tabs[0] as HTMLElement).click();
+    await flushTimers();
+  });
+  await waitFor("files rows re-render after view-mode round trip", () => document.querySelectorAll(".workspace-tree__row").length > 0);
+  ok(document.querySelectorAll(".workspace-tree__row").length > 0, "tree rows re-render after files<->changed view switch");
+}
+
+console.log(`\nworkspace tree scroll restore: ${passed} passed, ${failed} failed`);
+if (failed > 0) process.exit(1);
@@ -19,7 +19,6 @@ interface AppChromeProps {
  sidebarToggleTitle: string;
  workspacePanelMaximized: boolean;
  workspacePanelRenderable: boolean;
-  workspaceTogglePressed: boolean;
  workspacePanelLabel: string;
  onToggleSidebar: () => void;
  onToggleWorkspacePanel: () => void;
@@ -45,7 +44,6 @@ export function AppChrome({
  sidebarToggleTitle,
  workspacePanelMaximized,
  workspacePanelRenderable,
-  workspaceTogglePressed,
  workspacePanelLabel,
  onToggleSidebar,
  onToggleWorkspacePanel,
@@ -129,7 +127,6 @@ export function AppChrome({
            className={[
              "app-chrome__tools",
              "app-chrome__tools--fixed",
-              workspaceTogglePressed ? "app-chrome__tools--workspace-pressed" : "",
            ].filter(Boolean).join(" ")}
            aria-label={t("tabBar.commandSearch")}
          >
@@ -156,7 +153,6 @@ export function AppChrome({
          <div
            className={[
              "app-chrome__tools",
-              workspaceTogglePressed ? "app-chrome__tools--workspace-pressed" : "",
            ].filter(Boolean).join(" ")}
            aria-label={t("tabBar.commandSearch")}
          >
@@ -183,7 +179,6 @@ export function AppChrome({
            "app-chrome__panel-toggle",
            "app-chrome__panel-toggle--right",
            workspacePanelRenderable ? "app-chrome__panel-toggle--active" : "",
-            workspaceTogglePressed ? "app-chrome__panel-toggle--pressed" : "",
          ].filter(Boolean).join(" ")}
          type="button"
          onClick={onToggleWorkspacePanel}
@@ -20,6 +20,9 @@ export function PromptShelf({
  role = "dialog",
  decision = false,
  actionsRole = "listbox",
+  cardCollapsible = false,
+  collapsed = false,
+  onToggleCollapse,
 }: {
  className?: string;
  cardClassName?: string;
@@ -45,6 +48,11 @@ export function PromptShelf({
  // Select-then-confirm surfaces use listbox. Immediate actions are a group of
  // buttons so assistive technology does not announce them as pending choices.
  actionsRole?: "listbox" | "group";
+  // Whole-card click-to-collapse (used by the todo shelf): clicking anywhere
+  // on the card toggles collapsed; interactive children stop propagation.
+  cardCollapsible?: boolean;
+  collapsed?: boolean;
+  onToggleCollapse?: () => void;
 }) {
  return (
    <div
@@ -59,22 +67,40 @@ export function PromptShelf({
    >
      <div
        ref={barRef}
-        className={["prompt-shelf__card", cardClassName ?? ""].filter(Boolean).join(" ")}
+        className={[
+          "prompt-shelf__card",
+          cardCollapsible ? "prompt-shelf__card--collapsible" : "",
+          cardCollapsible && collapsed ? "prompt-shelf__card--collapsed" : "",
+          cardClassName ?? "",
+        ]
+          .filter(Boolean)
+          .join(" ")}
        role={role}
        aria-modal={role === "dialog" ? "false" : undefined}
        aria-labelledby={titleId}
-        tabIndex={-1}
+        tabIndex={cardCollapsible ? 0 : -1}
+        onClick={cardCollapsible ? onToggleCollapse : undefined}
+        onKeyDown={cardCollapsible && onToggleCollapse ? (event) => {
+          if (event.key === "Enter" || event.key === " ") {
+            event.preventDefault();
+            onToggleCollapse();
+          }
+        } : undefined}
      >
        <div className="prompt-shelf__content">
          <div className="prompt-shelf__header">
            <div className="prompt-shelf__copy">
              <div id={titleId} className="prompt-shelf__title">
                <span className="prompt-shelf__heading">{title}</span>
+                {meta && <span className="prompt-shelf__meta">{meta}</span>}
                {badges && <span className="prompt-shelf__badges">{badges}</span>}
              </div>
-              {meta && <div className="prompt-shelf__meta">{meta}</div>}
            </div>
-            {headerActions && <div className="prompt-shelf__header-actions">{headerActions}</div>}
+            {headerActions && (
+              <div className="prompt-shelf__header-actions" onClick={(event) => event.stopPropagation()}>
+                {headerActions}
+              </div>
+            )}
          </div>
          {crumbs}
          {children && <div className="prompt-shelf__body">{children}</div>}
@@ -85,23 +85,20 @@ export function TodoPanel({
      badges={<PromptBadge>{done}/{todos.length}</PromptBadge>}
      meta={summary}
      role="region"
+      cardClassName="prompt-shelf--todo"
+      cardCollapsible
+      collapsed={!open}
+      onToggleCollapse={() => setOpen((value) => {
+        const next = !value;
+        saveOpenState(stateKey, next);
+        return next;
+      })}
      headerActions={
-        <>
-          <PromptHeaderAction
-            onClick={() => setOpen((value) => {
-              const next = !value;
-              saveOpenState(stateKey, next);
-              return next;
-            })}
-          >
-            {open ? t("common.collapse") : t("common.expand")}
+        allDone && (
+          <PromptHeaderAction onClick={onDismiss}>
+            {t("common.close")}
          </PromptHeaderAction>
-          {allDone && (
-            <PromptHeaderAction onClick={onDismiss}>
-              {t("common.close")}
-            </PromptHeaderAction>
-          )}
-        </>
+        )
      }
    >
      {open && (
@@ -0,0 +1,97 @@
+import { lazy, Suspense, useEffect, useRef, useState } from "react";
+import { MoreHorizontal } from "lucide-react";
+
+import { Tooltip } from "./Tooltip";
+import type { TopicbarMoreMenuContentProps } from "./TopicbarMoreMenuContent";
+
+import { t } from "../lib/i18n";
+
+const loadMenuContent = () => import("./TopicbarMoreMenuContent");
+const TopicbarMoreMenuContent = lazy(async () => ({
+  default: (await loadMenuContent()).TopicbarMoreMenuContent,
+}));
+
+type TopicbarMoreMenuProps = Omit<TopicbarMoreMenuContentProps, "copied" | "initialFocus" | "onClose" | "onCopied">;
+
+/** Keeps the topic bar compact while loading overflow actions only on demand. */
+export function TopicbarMoreMenu(props: TopicbarMoreMenuProps) {
+  const rootRef = useRef<HTMLDivElement>(null);
+  const triggerRef = useRef<HTMLButtonElement>(null);
+  const [menuOpen, setMenuOpen] = useState(false);
+  const [initialFocus, setInitialFocus] = useState<"first" | "last">("first");
+  const [copied, setCopied] = useState(false);
+  const copiedTimerRef = useRef<number | null>(null);
+
+  const closeMenu = (restoreFocus: boolean) => {
+    setMenuOpen(false);
+    if (restoreFocus) triggerRef.current?.focus();
+  };
+
+  useEffect(() => {
+    if (!menuOpen) return;
+    const onPointerDown = (event: MouseEvent) => {
+      if (!rootRef.current?.contains(event.target as Node)) closeMenu(false);
+    };
+    const onKeyDown = (event: KeyboardEvent) => {
+      if (event.key === "Escape") closeMenu(true);
+    };
+    document.addEventListener("mousedown", onPointerDown);
+    document.addEventListener("keydown", onKeyDown);
+    return () => {
+      document.removeEventListener("mousedown", onPointerDown);
+      document.removeEventListener("keydown", onKeyDown);
+    };
+  }, [menuOpen]);
+
+  useEffect(() => () => {
+    if (copiedTimerRef.current != null) window.clearTimeout(copiedTimerRef.current);
+  }, []);
+
+  const markCopied = () => {
+    setCopied(true);
+    if (copiedTimerRef.current != null) window.clearTimeout(copiedTimerRef.current);
+    copiedTimerRef.current = window.setTimeout(() => setCopied(false), 1200);
+  };
+
+  const openFromKeyboard = (event: React.KeyboardEvent<HTMLButtonElement>) => {
+    if (event.key !== "ArrowDown" && event.key !== "ArrowUp") return;
+    event.preventDefault();
+    setInitialFocus(event.key === "ArrowUp" ? "last" : "first");
+    setMenuOpen(true);
+  };
+
+  return (
+    <div ref={rootRef} className={`topicbar__more${menuOpen ? " topicbar__more--open" : ""}`}>
+      <Tooltip label={t("topicBar.more")}>
+        <button
+          ref={triggerRef}
+          className="topicbar__action-btn topicbar__action-btn--icon topicbar__action-btn--utility"
+          type="button"
+          aria-label={t("topicBar.more")}
+          aria-haspopup="menu"
+          aria-expanded={menuOpen}
+          onPointerEnter={() => { void loadMenuContent(); }}
+          onFocus={() => { void loadMenuContent(); }}
+          onKeyDown={openFromKeyboard}
+          onClick={() => {
+            setInitialFocus("first");
+            setMenuOpen((open) => !open);
+          }}
+        >
+          <MoreHorizontal size={15} />
+        </button>
+      </Tooltip>
+      {menuOpen && (
+        <Suspense fallback={null}>
+          <TopicbarMoreMenuContent
+            {...props}
+            copied={copied}
+            initialFocus={initialFocus}
+            onClose={closeMenu}
+            onCopied={markCopied}
+          />
+        </Suspense>
+      )}
+    </div>
+  );
+}
@@ -0,0 +1,83 @@
+.topicbar__more-menu {
+  position: absolute;
+  right: 0;
+  top: calc(100% + 6px);
+  z-index: var(--z-topicbar-menu);
+  min-width: 168px;
+  padding: 5px;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  background: var(--bg-elev);
+  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.36);
+  --wails-draggable: no-drag;
+}
+
+.topicbar__menu-item {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  width: 100%;
+  padding: 8px 9px;
+  border: none;
+  border-radius: 6px;
+  background: transparent;
+  color: var(--fg-dim);
+  font: inherit;
+  font-size: 12.5px;
+  text-align: left;
+}
+
+.topicbar__menu-item:hover,
+.topicbar__menu-item:focus-visible {
+  color: var(--fg);
+  background: var(--button-bg);
+}
+
+.topicbar__menu-item:disabled {
+  cursor: not-allowed;
+  opacity: 0.5;
+}
+
+.topicbar__menu-item--active {
+  color: var(--accent);
+}
+
+.topicbar__more-export {
+  position: relative;
+}
+
+.topicbar__more-export-menu {
+  position: absolute;
+  /* The primary menu sits at the far right, so the submenu opens left. */
+  right: calc(100% - 8px);
+  top: -5px;
+  z-index: var(--z-topicbar-menu);
+  min-width: 168px;
+  padding: 5px;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  background: var(--bg-elev);
+  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.36);
+  --wails-draggable: no-drag;
+}
+
+.topicbar__more-export-menu button {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  width: 100%;
+  padding: 8px 9px;
+  border: none;
+  border-radius: 6px;
+  background: transparent;
+  color: var(--fg-dim);
+  font: inherit;
+  font-size: 12.5px;
+  text-align: left;
+}
+
+.topicbar__more-export-menu button:hover,
+.topicbar__more-export-menu button:focus-visible {
+  color: var(--fg);
+  background: var(--button-bg);
+}
@@ -0,0 +1,195 @@
+import { useEffect, useRef, useState, type KeyboardEvent as ReactKeyboardEvent } from "react";
+import {
+  Activity,
+  Check,
+  Copy,
+  Download,
+  FileDown,
+  FileImage,
+  FileJson,
+  FileText,
+  GitBranch,
+  TerminalSquare,
+} from "lucide-react";
+
+import "./TopicbarMoreMenuContent.css";
+
+import { writeClipboardText } from "../lib/clipboard";
+import { t } from "../lib/i18n";
+
+export interface TopicbarMoreMenuContentProps {
+  sessionHasContent: boolean;
+  getSessionMarkdown: () => string | Promise<string>;
+  exportSession: (format: "markdown" | "json" | "pdf" | "image") => void;
+  openChangedDock: () => void;
+  toggleTerminal: () => void;
+  prefetchTerminal?: () => void;
+  openSessionSummary: () => void;
+  tasksOpen: boolean;
+  copied: boolean;
+  initialFocus: "first" | "last";
+  onClose: (restoreFocus: boolean) => void;
+  onCopied: () => void;
+}
+
+function enabledItems(menu: HTMLElement): HTMLButtonElement[] {
+  return Array.from(menu.querySelectorAll<HTMLButtonElement>('[role="menuitem"]'))
+    .filter((item) => !item.disabled && item.closest('[role="menu"]') === menu);
+}
+
+function moveMenuFocus(event: ReactKeyboardEvent<HTMLDivElement>) {
+  if (!["ArrowDown", "ArrowUp", "Home", "End"].includes(event.key)) return;
+  event.preventDefault();
+  event.stopPropagation();
+  const items = enabledItems(event.currentTarget);
+  if (items.length === 0) return;
+  const current = items.indexOf(document.activeElement as HTMLButtonElement);
+  const next = event.key === "Home" ? 0
+    : event.key === "End" ? items.length - 1
+    : event.key === "ArrowDown" ? (current + 1 + items.length) % items.length
+    : (current - 1 + items.length) % items.length;
+  items[next]?.focus();
+}
+
+export function TopicbarMoreMenuContent({
+  sessionHasContent,
+  getSessionMarkdown,
+  exportSession,
+  openChangedDock,
+  toggleTerminal,
+  prefetchTerminal,
+  openSessionSummary,
+  tasksOpen,
+  copied,
+  initialFocus,
+  onClose,
+  onCopied,
+}: TopicbarMoreMenuContentProps) {
+  const menuRef = useRef<HTMLDivElement>(null);
+  const exportTriggerRef = useRef<HTMLButtonElement>(null);
+  const exportMenuRef = useRef<HTMLDivElement>(null);
+  const [exportOpen, setExportOpen] = useState(false);
+
+  useEffect(() => {
+    const items = menuRef.current ? enabledItems(menuRef.current) : [];
+    (initialFocus === "last" ? items[items.length - 1] : items[0])?.focus();
+  }, [initialFocus]);
+
+  useEffect(() => {
+    if (!exportOpen || !exportMenuRef.current) return;
+    enabledItems(exportMenuRef.current)[0]?.focus();
+  }, [exportOpen]);
+
+  const closeAndRun = (action: () => void) => {
+    onClose(true);
+    action();
+  };
+
+  const copySession = async () => {
+    try {
+      await writeClipboardText(await getSessionMarkdown());
+    } catch {
+      /* clipboard unavailable */
+    }
+    onCopied();
+  };
+
+  const onMainMenuKeyDown = (event: ReactKeyboardEvent<HTMLDivElement>) => {
+    if (event.key === "Escape") {
+      event.preventDefault();
+      event.stopPropagation();
+      onClose(true);
+      return;
+    }
+    moveMenuFocus(event);
+  };
+
+  const onExportMenuKeyDown = (event: ReactKeyboardEvent<HTMLDivElement>) => {
+    if (event.key === "ArrowLeft" || event.key === "Escape") {
+      event.preventDefault();
+      event.stopPropagation();
+      setExportOpen(false);
+      exportTriggerRef.current?.focus();
+      return;
+    }
+    moveMenuFocus(event);
+  };
+
+  return (
+    <div ref={menuRef} className="topicbar__more-menu" role="menu" aria-label={t("topicBar.more")} onKeyDown={onMainMenuKeyDown}>
+      <button tabIndex={-1} className="topicbar__menu-item" type="button" role="menuitem" onClick={() => closeAndRun(() => { void copySession(); })}>
+        {copied ? <Check size={14} /> : <Copy size={14} />}
+        <span>{copied ? t("msg.copied") : t("topicBar.copyAll")}</span>
+      </button>
+      <div className={`topicbar__more-export${exportOpen ? " topicbar__more-export--open" : ""}`}>
+        <button
+          ref={exportTriggerRef}
+          tabIndex={-1}
+          className="topicbar__menu-item"
+          type="button"
+          role="menuitem"
+          aria-haspopup="menu"
+          aria-expanded={exportOpen}
+          disabled={!sessionHasContent}
+          onKeyDown={(event) => {
+            if (event.key !== "ArrowRight") return;
+            event.preventDefault();
+            event.stopPropagation();
+            setExportOpen(true);
+          }}
+          onClick={() => setExportOpen((open) => !open)}
+        >
+          <Download size={14} />
+          <span>{t("topicBar.export")}</span>
+        </button>
+        {exportOpen && (
+          <div ref={exportMenuRef} className="topicbar__more-export-menu" role="menu" aria-label={t("topicBar.export")} onKeyDown={onExportMenuKeyDown}>
+            <button tabIndex={-1} type="button" role="menuitem" onClick={() => closeAndRun(() => exportSession("markdown"))}>
+              <FileText size={13} />
+              <span>{t("topicBar.exportMarkdown")}</span>
+            </button>
+            <button tabIndex={-1} type="button" role="menuitem" onClick={() => closeAndRun(() => exportSession("json"))}>
+              <FileJson size={13} />
+              <span>{t("topicBar.exportJson")}</span>
+            </button>
+            <button tabIndex={-1} type="button" role="menuitem" onClick={() => closeAndRun(() => exportSession("pdf"))}>
+              <FileDown size={13} />
+              <span>{t("topicBar.exportPdf")}</span>
+            </button>
+            <button tabIndex={-1} type="button" role="menuitem" onClick={() => closeAndRun(() => exportSession("image"))}>
+              <FileImage size={13} />
+              <span>{t("topicBar.exportImage")}</span>
+            </button>
+          </div>
+        )}
+      </div>
+      <button tabIndex={-1} className="topicbar__menu-item" type="button" role="menuitem" onClick={() => closeAndRun(openChangedDock)}>
+        <GitBranch size={14} />
+        <span>{t("workspace.changedTab")}</span>
+      </button>
+      <button
+        tabIndex={-1}
+        className="topicbar__menu-item"
+        type="button"
+        role="menuitem"
+        onPointerEnter={prefetchTerminal}
+        onFocus={prefetchTerminal}
+        onClick={() => closeAndRun(toggleTerminal)}
+      >
+        <TerminalSquare size={14} />
+        <span>{t("rightDock.terminal")}</span>
+      </button>
+      <button
+        tabIndex={-1}
+        className={`topicbar__menu-item${tasksOpen ? " topicbar__menu-item--active" : ""}`}
+        type="button"
+        role="menuitem"
+        aria-pressed={tasksOpen}
+        onClick={() => closeAndRun(openSessionSummary)}
+      >
+        <Activity size={14} />
+        <span>{t("summary.session")}</span>
+      </button>
+    </div>
+  );
+}
@@ -11,7 +11,6 @@ import {
  ChevronDown,
  ChevronRight,
  FileText,
-  Folder,
  FolderTree,
  FolderX,
  GitBranch,
@@ -39,8 +38,15 @@ import { closeWorkspacePreviewTab } from "../lib/workspacePreviewTabs";
 import { useWorkspaceRefresh } from "../lib/workspaceRefreshStore";
 import { useWorkspaceRefreshInvalidation, workspaceRefreshFallbackSequence } from "../lib/workspaceRefreshInvalidation";
 import { createWorkspaceRefreshScheduler } from "../lib/workspaceRefreshScheduler";
+import {
+  beginKeyedResourceRequest,
+  emptyKeyedResource,
+  rejectKeyedResourceRequest,
+  resolveKeyedResourceRequest,
+} from "../lib/keyedResource";
 import { shouldScrollWorkspaceTreeSelection } from "../lib/workspaceTreeReveal";
 import { mergeWorkspaceSearchResults } from "../lib/workspaceTreeSearch";
+import { useWorkspaceTreeScrollPersistence } from "../lib/useWorkspaceTreeScrollPersistence";
 import {
  readWorkspaceTreeMemory,
  rememberWorkspaceTreeOpenDirs,
@@ -48,7 +54,6 @@ import {
  touchWorkspaceTreeVisit,
  workspaceTreeVisitId,
 } from "../lib/workspaceTreeMemory";
-import { useWorkspaceTreeScrollPersistence } from "../lib/useWorkspaceTreeScrollPersistence";
 import { loadLayoutSize, loadOptionalLayoutSize } from "../lib/layoutPreferences";
 import {
  RIGHT_DOCK_PREVIEW_DEFAULT_WIDTH,
@@ -76,8 +81,9 @@ import { Markdown } from "./Markdown";
 import { Tooltip } from "./Tooltip";
 import { AnchoredPopover } from "./AnchoredPopover";
 import { MarkdownImageTabContext } from "./MarkdownImageContext";
-import { WorkspaceFileIcon } from "./WorkspaceFileIcon";
 import { WorkspaceMediaPreview } from "./WorkspaceMediaPreview";
+import { buildWorkspacePathBreadcrumbs, WorkspacePathBreadcrumbs } from "./WorkspacePathBreadcrumbs";
+import { WorkspaceTreeRow, type WorkspaceTreeRowData } from "./WorkspaceTreeRow";
 import { WorkspaceTreeMenu } from "./WorkspaceTreeMenu";
 import { WORKSPACE_TURN_VERIFICATION_ID, WorkspaceTurnVerification } from "./WorkspaceTurnVerification";
 import { useWorkspaceChangesResource } from "../lib/useWorkspaceChangesResource";
@@ -87,12 +93,6 @@ import {
  workspaceParentDirs as parentDirs, workspaceParentPath as parentPath,
  workspaceShortCwd as shortCwd, workspaceTopLevelDirPath as topLevelDirPath,
 } from "../lib/workspacePanelFormat";
-import {
-  beginKeyedResourceRequest,
-  emptyKeyedResource,
-  rejectKeyedResourceRequest,
-  resolveKeyedResourceRequest,
-} from "../lib/keyedResource";

 const WORKSPACE_TREE_MIN_WIDTH = 140;
 const WORKSPACE_TREE_DEFAULT_WIDTH = 300;
@@ -120,18 +120,6 @@ function clampWorkspaceTreeWidth(width: number, panelWidth?: number): number {
  });
 }

-interface TreeRow {
-  key: string;
-  path: string;
-  depth: number;
-  entry: DirEntry;
-  active: boolean;
-  isOpen?: boolean;
-  isSearch?: boolean;
-  compactPaths?: string[];
-  displayName?: string;
-}
-
 export function WorkspacePanel({
  open,
  tabId,
@@ -204,6 +192,8 @@ export function WorkspacePanel({
    && verificationRevealRequest.currentSummary === completionSummary ? verificationRevealRequest : null;
  const visibleCompletionSummary = activeVerificationRevealRequest?.summary ?? completionSummary;
  const workspaceScopeKey = workspaceScopeKeyProp ?? `${workspaceTabId}\u0000${cwd ?? ""}`;
+  const lastWorkspaceScopeKeyRef = useRef(workspaceScopeKey);
+  const scopeSwitchPendingRef = useRef(false);
  const workspaceMemoryKey = workspaceMemoryKeyProp ?? workspaceScopeKey;
  const workspaceMemoryVisitId = workspaceMemoryVisitIdProp ?? workspaceTreeVisitId(workspaceMemoryKey);
  const workspaceRefresh = useWorkspaceRefresh(workspaceTabId, workspaceScopeKey, open);
@@ -231,6 +221,12 @@ export function WorkspacePanel({
    () => initialWorkspaceMemory?.selectedChangePath ?? null,
  );
  const [openTabs, setOpenTabs] = useState<string[]>([]);
+  // Independent "recently opened" history: survives closing all preview tabs
+  // (openTabs is the live preview state) and app restarts, so the recent-files
+  // menu keeps the user's file history even after the previews are dismissed.
+  const [recentPaths, setRecentPaths] = useState<string[]>(() =>
+    (initialWorkspaceMemory?.recentPaths ?? []).slice(0, WORKSPACE_MAX_PREVIEW_TABS),
+  );
  const [previewResource, setPreviewResource] = useState(() => emptyKeyedResource<FilePreview>());
  const [viewMode, setViewMode] = useState<"files" | "changed">(initialViewMode);
  const selectedPath = viewMode === "changed" ? selectedChangePath : selectedFilePath;
@@ -273,7 +269,6 @@ export function WorkspacePanel({
  const lastChangeListRequestIdRef = useRef<number | null>(null);
  const dismissedChangeListRequestIdRef = useRef<number | null>(null);
  const currentWorkspaceScopeKeyRef = useRef(workspaceScopeKey);
-  const lastWorkspaceScopeKeyRef = useRef(workspaceScopeKey);
  const changeDetailRequestIdRef = useRef(0);
  const gitHistoryRequestIdRef = useRef(0);
  const previewRequestIdRef = useRef(0);
@@ -371,6 +366,11 @@ export function WorkspacePanel({
    rememberWorkspaceTreeState(workspaceMemoryKey, { treeWidth, treeWidthMode });
  }, [treeWidth, treeWidthMode, workspaceMemoryKey]);

+  useEffect(() => {
+    if (memoryRestorePendingRef.current) return;
+    rememberWorkspaceTreeState(workspaceMemoryKey, { recentPaths });
+  }, [recentPaths, workspaceMemoryKey]);
+
  useEffect(() => {
    if (memoryRestorePendingRef.current || dockTreeWidth == null || dockPreviewWidth == null) return;
    rememberWorkspaceTreeState(workspaceMemoryKey, { dockTreeWidth, dockPreviewWidth });
@@ -423,6 +423,10 @@ export function WorkspacePanel({
      setChangeDetailResource(emptyKeyedResource());
      return;
    }
+    // Scope switch must not request the previous scope's selected change:
+    // the selection is preserved for the original scope, but a request must
+    // not fire for the just-switched scope before the scope effect settles.
+    if (scopeSwitchPendingRef.current) return;
    const requestKey = `${requestScopeKey}\u0000change\u0000${requestPath}`;
    setChangeDetailResource((current) => beginKeyedResourceRequest(current, requestKey, requestId, workspaceRefresh.revisions.content));
    try {
@@ -489,7 +493,11 @@ export function WorkspacePanel({
        setTreeWidth(initialWorkspaceSplitTreeWidth({
          panelWidth,
          railWidth: WORKSPACE_TREE_RAIL_WIDTH,
-          savedTreeWidth: null,
+          // Preserve a user-resized (manual) tree width: only first-time
+          // splits (no saved width yet) default to an even 50/50 division.
+          // Reopening a file after closing its preview must keep the
+          // remembered width, not snap back to the initial split.
+          savedTreeWidth: treeWidthMode === "manual" ? treeWidth : null,
          treeMinWidth: WORKSPACE_TREE_MIN_WIDTH,
          previewMinWidth: WORKSPACE_PREVIEW_MIN_WIDTH,
        }));
@@ -508,6 +516,7 @@ export function WorkspacePanel({
      });
      setFilter("");
      setOpenTabs((tabs) => [...tabs.filter((tab) => tab !== path), path].slice(-WORKSPACE_MAX_PREVIEW_TABS));
+      setRecentPaths((paths) => [...paths.filter((p) => p !== path), path].slice(-WORKSPACE_MAX_PREVIEW_TABS));
      const dirs = parentDirs(path);
      updateOpenDirs((prev) => new Set([...Array.from(prev), ...dirs]));
      dirs.forEach((dir) => void loadDir(dir));
@@ -541,6 +550,7 @@ export function WorkspacePanel({
    if (!open) return;
    if (lastWorkspaceScopeKeyRef.current === workspaceScopeKey) return;
    lastWorkspaceScopeKeyRef.current = workspaceScopeKey;
+    scopeSwitchPendingRef.current = true;
    workingTreeRefreshSchedulerRef.current?.cancel();
    gitMetaRefreshSchedulerRef.current?.cancel();
    changeDetailRequestIdRef.current += 1;
@@ -755,7 +765,11 @@ export function WorkspacePanel({
    if (!open) return;
    if (viewMode === "changed") {
      void loadWorkspaceChanges();
-      if (selectedPath) void loadChangeDetail();
+      // A scope switch just happened in this render batch: the previous
+      // scope's selected change must not be re-requested, but the selection
+      // itself is preserved for when the user returns to that scope.
+      if (selectedPath && !scopeSwitchPendingRef.current) void loadChangeDetail();
+      scopeSwitchPendingRef.current = false;
      if (commitHistoryOpen) void loadGitHistory();
    } else {
      changeDetailRequestIdRef.current += 1;
@@ -980,14 +994,18 @@ export function WorkspacePanel({

  const changedMode = viewMode === "changed";
  const currentFileName = selectedPath ? basename(selectedPath) : t("workspace.noFile");
-  const currentFileDir = selectedPath ? parentPath(selectedPath) : "";
  const previewTitle = changedMode && !selectedPath
    ? scopedChangeRows ? t("context.sessionChanges") : t("workspace.changedTab")
    : currentFileName;
-  const previewSubtitle = changedMode && !selectedPath
-    ? scopedChangeRows ? t("context.changedMeta", { count: scopedChangeRows.length }) : shortCwd(cwd) || t("workspace.title")
-    : currentFileDir;
-  const recentFiles = useMemo(() => [...openTabs].reverse(), [openTabs]);
+  const activeSelectedPath = selectedPath;
+  // Changed overview shows just the project name (matching the file-preview
+  // breadcrumb); hovering reveals the full absolute workspace root.
+  const previewSubtitleCrumbs = changedMode && !selectedChangePath && !scopedChangeRows
+    ? (cwd ? [{ label: basename(cwd), full: cwd }] : [])
+    : [];
+  const previewFullPath = activeSelectedPath || "";
+  const previewCrumbs = buildWorkspacePathBreadcrumbs(cwd, previewFullPath);
+  const recentFiles = useMemo(() => [...recentPaths].reverse(), [recentPaths]);

  const workspaceSearchFallbackSequence = workspaceRefreshFallbackSequence(workspaceRefresh);

@@ -1026,7 +1044,7 @@ export function WorkspacePanel({
      .sort((a, b) => a.path.localeCompare(b.path));
  }, [entriesByDir, filter, scopedFilePaths, searchResults]);

-  const treeRows = useMemo<TreeRow[]>(() => {
+  const treeRows = useMemo<WorkspaceTreeRowData[]>(() => {
    if (flattened) {
      return flattened.map(({ path, entry }) => ({
        key: path,
@@ -1037,7 +1055,7 @@ export function WorkspacePanel({
        isSearch: true,
      }));
    }
-    const acc: TreeRow[] = [];
+    const acc: WorkspaceTreeRowData[] = [];
    const build = (dir: string, depth: number) => {
      const entries = entriesByDir[dir] ?? [];
      for (const entry of entries) {
@@ -1097,10 +1115,48 @@ export function WorkspacePanel({
    overscan: 10,
    directDomUpdates: true,
  });
+  // Restore the persisted scroll position once the tree has grown tall enough
+  // to actually reach it. The tree loads asynchronously layer by layer: the
+  // first render usually has only the top-level rows, so scrolling then would
+  // clamp the saved offset to the (tiny) current scrollable range and lose the
+  // position forever. Keep a pending target and retry on every tree change
+  // until the tree's total height exceeds it, then scroll once.
+  const pendingScrollRestoreRef = useRef<number | null>(null);
+  // Reset the pending restore whenever the view mode changes: the saved offset
+  // belongs to the previous mode's tree, and re-applying it to a shorter list
+  // (e.g. files -> changed) scrolls past the end and leaves a blank band at
+  // the top. Each mode restores its own offset on its own data.
+  const previousViewModeRef = useRef(viewMode);
+  if (previousViewModeRef.current !== viewMode) {
+    previousViewModeRef.current = viewMode;
+    pendingScrollRestoreRef.current = null;
+  }
+  useEffect(() => {
+    if (!open || treeRows.length === 0) return;
+    if (pendingScrollRestoreRef.current == null) {
+      const saved = readWorkspaceTreeMemory(workspaceMemoryKey)?.scrollTop;
+      if (saved == null || !Number.isFinite(saved) || saved <= 0) return;
+      pendingScrollRestoreRef.current = saved;
+    }
+    const target = pendingScrollRestoreRef.current;
+    // A saved offset is only reachable once the tree's total height exceeds
+    // the offset by at least one viewport: the maximum scroll position is
+    // totalSize - viewportHeight. Using totalSize < target would clear the
+    // pending restore once content just barely exceeds the offset, but before
+    // it provides enough scrollable space — the browser then clamps the scroll
+    // and the deep-scroll restore is silently lost. Use the virtualizer's own
+    // viewport rect (reliable after remount) rather than reading clientHeight
+    // at restore time, which can be 0 while the tree is still settling.
+    const viewportHeight = virtualizer.scrollRect?.height ?? treeRef.current?.clientHeight ?? 0;
+    if (virtualizer.getTotalSize() - viewportHeight < target) return; // not enough scrollable space yet
+    virtualizer.scrollToOffset(target, { align: "start" });
+    pendingScrollRestoreRef.current = null;
+  }, [open, treeRows.length, virtualizer.getTotalSize(), virtualizer.scrollRect?.height, workspaceMemoryKey, virtualizer]);
+
  const virtualTreeItems = virtualizer.getVirtualItems();
  const compactProbePaths = virtualTreeItems
    .map((item) => treeRows[item.index])
-    .filter((row): row is TreeRow => Boolean(row?.entry.isDir && entriesByDir[row.path] === undefined))
+    .filter((row): row is WorkspaceTreeRowData => Boolean(row?.entry.isDir && entriesByDir[row.path] === undefined))
    .map((row) => row.path);
  const compactProbeKey = compactProbePaths.join("\u0000");

@@ -1265,6 +1321,7 @@ export function WorkspacePanel({
          railWidth: WORKSPACE_TREE_RAIL_WIDTH,
          treeMinWidth: WORKSPACE_TREE_MIN_WIDTH,
          previewMinWidth: WORKSPACE_PREVIEW_MIN_WIDTH,
+          treeOnRight: true,
        });
        liveResize.schedule(nextWidth);
      };
@@ -1291,7 +1348,7 @@ export function WorkspacePanel({
    (event: KeyboardEvent<HTMLButtonElement>) => {
      if (event.key === "ArrowLeft" || event.key === "ArrowRight") {
        event.preventDefault();
-        setSavedTreeWidth(effectiveTreeWidth + (event.key === "ArrowRight" ? 16 : -16));
+        setSavedTreeWidth(effectiveTreeWidth + (event.key === "ArrowLeft" ? 16 : -16));
      } else if (event.key === "Home") {
        event.preventDefault();
        setSavedTreeWidth(WORKSPACE_TREE_MIN_WIDTH);
@@ -1407,96 +1464,14 @@ export function WorkspacePanel({
    }
  };

-  const renderNormalRow = (row: TreeRow) => {
-    const { path, depth, entry, isOpen, active, compactPaths = [path], displayName = entry.name } = row;
-    return (
-      <button
-        key={path}
-        className={`workspace-tree__row${active ? " workspace-tree__row--active" : ""}`}
-        data-workspace-path={path}
-        draggable
-        onDragStart={(event) => startTreeDrag(event, path, entry.isDir)}
-        onClick={() => {
-          if (entry.isDir) {
-            toggleDir(path, compactPaths);
-          } else {
-            if (selectedPath === path) {
-              setSelectedFilePath(null);
-            } else {
-              selectFile(path);
-            }
-          }
-        }}
-        onContextMenu={(event) => openTreeMenu(event, path, entry.isDir)}
-        style={{ paddingLeft: 8 + depth * 14 }}
-      >
-        {depth > 0 && (
-          <span className="workspace-tree__guides" aria-hidden="true">
-            {Array.from({ length: depth }, (_, index) => (
-              <span
-                className="workspace-tree__guide"
-                key={index}
-                style={{ left: 14 + index * 14 }}
-              />
-            ))}
-          </span>
-        )}
-        {entry.isDir ? (
-          <ChevronRight
-            size={13}
-            className={`workspace-tree__chev ${isOpen ? "workspace-tree__chev--open" : ""}`}
-            style={{
-              transition: "transform 0.15s ease",
-              transform: isOpen ? "rotate(90deg)" : "rotate(0deg)",
-            }}
-          />
-        ) : (
-          <span className="workspace-tree__chev" />
-        )}
-        {entry.isDir ? (
-          <Folder size={14} className="workspace-tree__icon workspace-tree__icon--dir" />
-        ) : (
-          <WorkspaceFileIcon fileName={entry.name} />
-        )}
-        <span className="workspace-tree__name">{displayName}</span>
-      </button>
-    );
-  };
-
-  const renderSearchRow = (row: TreeRow) => {
-    const { path, entry, active } = row;
-    const dir = parentPath(path);
-    return (
-      <button
-        key={path}
-        className={`workspace-tree__row workspace-tree__row--search${active ? " workspace-tree__row--active" : ""}`}
-        data-workspace-path={path}
-        draggable
-        onDragStart={(event) => startTreeDrag(event, path, entry.isDir)}
-        onClick={() => {
-          if (entry.isDir) {
-            toggleDir(path);
-          } else {
-            if (selectedPath === path) {
-              setSelectedFilePath(null);
-            } else {
-              selectFile(path);
-            }
-          }
-        }}
-        onContextMenu={(event) => openTreeMenu(event, path, entry.isDir)}
-      >
-        {entry.isDir ? (
-          <Folder size={14} className="workspace-tree__icon workspace-tree__icon--dir" />
-        ) : (
-          <WorkspaceFileIcon fileName={entry.name} />
-        )}
-        <span className="workspace-tree__result">
-          <span className="workspace-tree__result-name">{basename(path)}</span>
-          {dir && <span className="workspace-tree__result-dir">{dir}</span>}
-        </span>
-      </button>
-    );
+  const activateTreeRow = (row: WorkspaceTreeRowData) => {
+    if (row.entry.isDir) {
+      toggleDir(row.path, row.compactPaths ?? [row.path]);
+    } else if (selectedPath === row.path) {
+      setSelectedFilePath(null);
+    } else {
+      selectFile(row.path);
+    }
  };

  const isMarkdown = selectedPath?.toLowerCase().endsWith(".md") ?? false;
@@ -1511,6 +1486,18 @@ export function WorkspacePanel({
      !preview.binary &&
      !isMarkdown,
  );
+  // The preview body must keep its flex-column layout while a code file is
+  // loading. Switching it to the padded block layout mid-load and back again
+  // makes WebKit leave stale gaps between rows once the viewer mounts.
+  const codePreviewLayoutActive = Boolean(
+    selectedFilePath &&
+      !changedMode &&
+      !isMarkdown &&
+      !previewErr &&
+      !preview?.err &&
+      !preview?.kind &&
+      !preview?.binary,
+  );
  const openCodeSearch = () => {
    if (!codePreviewActive || !selectedPath) return;
    setCodeSearchRequestPath(selectedPath);
@@ -1556,7 +1543,8 @@ export function WorkspacePanel({
              <Tooltip label={selectedPath ?? undefined}>
                <span className="workspace-current-file__name">{previewTitle}</span>
              </Tooltip>
-              {previewSubtitle && <span className="workspace-current-file__path">{previewSubtitle}</span>}
+              <WorkspacePathBreadcrumbs crumbs={previewSubtitleCrumbs} />
+              <WorkspacePathBreadcrumbs crumbs={previewCrumbs} />
            </div>
            <Tooltip label={t("workspace.recentFiles")}>
              <button
@@ -1591,6 +1579,19 @@ export function WorkspacePanel({
                {maximized ? <Minimize2 size={15} /> : <Maximize2 size={15} />}
              </button>
            </Tooltip>
+            {previewVisible && !changedMode && (
+              <Tooltip label={actualTreeVisible ? t("workspace.hideTree") : t("workspace.showTree")}>
+                <button
+                  className={`workspace-iconbtn${actualTreeVisible ? " workspace-iconbtn--on" : ""}`}
+                  type="button"
+                  aria-label={actualTreeVisible ? t("workspace.hideTree") : t("workspace.showTree")}
+                  aria-pressed={actualTreeVisible}
+                  onClick={toggleTreeRail}
+                >
+                  <FolderTree size={15} />
+                </button>
+              </Tooltip>
+            )}
            {selectedPath && (
              <Tooltip label={t("workspace.closePreview")}>
                <button className="workspace-iconbtn" onClick={closePreviewArea}>
@@ -1672,7 +1673,7 @@ export function WorkspacePanel({
        </div>

        <div
-          className={`workspace-preview__body${selectedPath && !changedMode && !isMarkdown && !previewErr && !preview?.err && !preview?.kind && !preview?.binary ? " workspace-preview__body--code" : ""}`}
+          className={`workspace-preview__body${codePreviewLayoutActive ? " workspace-preview__body--code" : ""}`}
          ref={previewBodyRef}
          onContextMenu={openSelectionMenu}
          onMouseUp={showSelectionToolbar}
@@ -2022,22 +2023,6 @@ export function WorkspacePanel({
        </div>
      </section>}

-      {showTreeRail && (
-        <section className="workspace-tree-rail" aria-label={actualTreeVisible ? t("workspace.hideTree") : t("workspace.showTree")}>
-          <Tooltip label={actualTreeVisible ? t("workspace.hideTree") : t("workspace.showTree")} side="right">
-            <button
-              className={`workspace-tree-reveal workspace-iconbtn${actualTreeVisible ? " workspace-iconbtn--on" : ""}`}
-              type="button"
-              aria-label={actualTreeVisible ? t("workspace.hideTree") : t("workspace.showTree")}
-              aria-pressed={actualTreeVisible}
-              onClick={toggleTreeRail}
-            >
-              <FolderTree size={15} />
-            </button>
-          </Tooltip>
-        </section>
-      )}
-
      {actualTreeVisible && previewVisible && (
        <button
          className="workspace-tree-resizer"
@@ -2141,8 +2126,8 @@ export function WorkspacePanel({
        <div
          className="workspace-tree"
          ref={treeRef}
-          onContextMenu={openTreeBlankMenu}
          onScroll={onWorkspaceTreeScroll}
+          onContextMenu={openTreeBlankMenu}
          style={{
            height: "100%",
            overflow: "auto",
@@ -2173,7 +2158,12 @@ export function WorkspacePanel({
                      width: "100%",
                    }}
                  >
-                    {item.isSearch ? renderSearchRow(item) : renderNormalRow(item)}
+                    <WorkspaceTreeRow
+                      row={item}
+                      onActivate={activateTreeRow}
+                      onDragStart={startTreeDrag}
+                      onContextMenu={openTreeMenu}
+                    />
                  </div>
                );
              })}
@@ -0,0 +1,38 @@
+import { workspaceBasename as basename, workspaceParentPath as parentPath } from "../lib/workspacePanelFormat";
+import { Tooltip } from "./Tooltip";
+
+export interface WorkspacePathBreadcrumb {
+  label: string;
+  full: string;
+}
+
+export function buildWorkspacePathBreadcrumbs(cwd: string | undefined, path: string): WorkspacePathBreadcrumb[] {
+  if (!path) return [];
+  const root = basename(cwd ?? "");
+  const dirParts = parentPath(path).split("/").filter(Boolean);
+  const dirCrumbs: WorkspacePathBreadcrumb[] = [];
+  let currentPath = "";
+  for (const part of dirParts) {
+    currentPath += `${currentPath ? "/" : ""}${part}`;
+    dirCrumbs.push({ label: part, full: `${cwd ?? ""}/${currentPath}` });
+  }
+  const crumbs = [{ label: root, full: cwd ?? "" }];
+  if (dirParts.length > 0 && dirParts[0] !== root) crumbs.push(...dirCrumbs);
+  return crumbs;
+}
+
+export function WorkspacePathBreadcrumbs({ crumbs }: { crumbs: WorkspacePathBreadcrumb[] }) {
+  if (crumbs.length === 0) return null;
+  return (
+    <span className="workspace-current-file__path">
+      {crumbs.map((crumb, index) => (
+        <span key={index} className="workspace-current-file__crumb">
+          {index > 0 && <span className="workspace-current-file__crumb-sep" aria-hidden="true">›</span>}
+          <Tooltip label={crumb.full}>
+            <span>{crumb.label}</span>
+          </Tooltip>
+        </span>
+      ))}
+    </span>
+  );
+}
@@ -0,0 +1,96 @@
+import type { DragEvent, MouseEvent } from "react";
+import { ChevronRight, Folder } from "lucide-react";
+import type { DirEntry } from "../lib/types";
+import { workspaceBasename as basename, workspaceParentPath as parentPath } from "../lib/workspacePanelFormat";
+import { WorkspaceFileIcon } from "./WorkspaceFileIcon";
+
+export interface WorkspaceTreeRowData {
+  key: string;
+  path: string;
+  depth: number;
+  entry: DirEntry;
+  active: boolean;
+  isOpen?: boolean;
+  isSearch?: boolean;
+  compactPaths?: string[];
+  displayName?: string;
+}
+
+export function WorkspaceTreeRow({
+  row,
+  onActivate,
+  onDragStart,
+  onContextMenu,
+}: {
+  row: WorkspaceTreeRowData;
+  onActivate: (row: WorkspaceTreeRowData) => void;
+  onDragStart: (event: DragEvent<HTMLElement>, path: string, isDir: boolean) => void;
+  onContextMenu: (event: MouseEvent<HTMLElement>, path: string, isDir: boolean) => void;
+}) {
+  const { path, depth, entry, isOpen, active, displayName = entry.name } = row;
+  if (row.isSearch) {
+    const dir = parentPath(path);
+    return (
+      <button
+        className={`workspace-tree__row workspace-tree__row--search${active ? " workspace-tree__row--active" : ""}`}
+        data-workspace-path={path}
+        draggable
+        onDragStart={(event) => onDragStart(event, path, entry.isDir)}
+        onClick={() => onActivate(row)}
+        onContextMenu={(event) => onContextMenu(event, path, entry.isDir)}
+      >
+        {entry.isDir ? (
+          <Folder size={14} className="workspace-tree__icon workspace-tree__icon--dir" />
+        ) : (
+          <WorkspaceFileIcon fileName={entry.name} />
+        )}
+        <span className="workspace-tree__result">
+          <span className="workspace-tree__result-name">{basename(path)}</span>
+          {dir && <span className="workspace-tree__result-dir">{dir}</span>}
+        </span>
+      </button>
+    );
+  }
+
+  return (
+    <button
+      className={`workspace-tree__row${active ? " workspace-tree__row--active" : ""}`}
+      data-workspace-path={path}
+      draggable
+      onDragStart={(event) => onDragStart(event, path, entry.isDir)}
+      onClick={() => onActivate(row)}
+      onContextMenu={(event) => onContextMenu(event, path, entry.isDir)}
+      style={{ paddingLeft: 8 + depth * 14 }}
+    >
+      {depth > 0 && (
+        <span className="workspace-tree__guides" aria-hidden="true">
+          {Array.from({ length: depth }, (_, index) => (
+            <span
+              className="workspace-tree__guide"
+              key={index}
+              style={{ left: 14 + index * 14 }}
+            />
+          ))}
+        </span>
+      )}
+      {entry.isDir ? (
+        <ChevronRight
+          size={13}
+          className={`workspace-tree__chev ${isOpen ? "workspace-tree__chev--open" : ""}`}
+          style={{
+            transition: "transform 0.15s ease",
+            transform: isOpen ? "rotate(90deg)" : "rotate(0deg)",
+          }}
+        />
+      ) : (
+        <span className="workspace-tree__chev" />
+      )}
+      {entry.isDir ? (
+        <Folder size={14} className="workspace-tree__icon workspace-tree__icon--dir" />
+      ) : (
+        <WorkspaceFileIcon fileName={entry.name} />
+      )}
+      <span className="workspace-tree__name">{displayName}</span>
+    </button>
+  );
+}
@@ -346,6 +346,28 @@ export default function LineNumberCode({
    directDomUpdates: true,
  });

+  // The virtualizer writes positioning straight onto DOM nodes (container
+  // height, scroll offset, per-row transforms). When a large (virtual) file
+  // stays mounted via SWR and is replaced by a small (non-virtual) file, React
+  // reuses those nodes; clear the direct DOM writes so the non-virtual rows
+  // lay out fresh instead of keeping stale offsets and gaps.
+  useEffect(() => {
+    if (isVirtual) return;
+    const scrollEl = scrollRef.current;
+    if (!scrollEl) return;
+    scrollEl.scrollTop = 0;
+    const wrap = scrollEl.querySelector<HTMLElement>(".code-lines-wrap");
+    if (!wrap) return;
+    wrap.style.removeProperty("height");
+    wrap.querySelectorAll<HTMLElement>("[data-line-index]").forEach((row) => {
+      row.style.removeProperty("transform");
+      row.style.removeProperty("position");
+      row.style.removeProperty("top");
+      row.style.removeProperty("left");
+      row.style.removeProperty("width");
+    });
+  }, [isVirtual]);
+
  const scrollToLine = useCallback(
    (index: number) => {
      if (!scrollRef.current) return;
@@ -407,6 +429,7 @@ export default function LineNumberCode({
        key={index}
        data-line-index={index}
        className={`code-line-row${isCurrent ? " code-line-row--current" : ""}${isDimmed ? " code-line-row--dim" : ""}`}
+        style={{ transform: "none" }}
      >
        {showLineNumbers !== false && (
          <span
@@ -615,6 +638,12 @@ export default function LineNumberCode({
                  top: 0,
                  left: 0,
                  width: "100%",
+                  // directDomUpdates writes the transform straight onto the
+                  // DOM, but right after switching a non-virtual view to a
+                  // virtual one the virtualizer may emit before its element
+                  // cache is populated; rendering the offset here keeps the
+                  // rows positioned (no stack-up) until then.
+                  transform: `translate3d(0, ${row.start}px, 0)`,
                }}
              >
                {renderRow(row.index)}
@@ -622,7 +651,7 @@ export default function LineNumberCode({
            ))}
          </div>
        ) : (
-          <div className="code-lines-wrap">
+          <div className="code-lines-wrap" style={{ height: undefined }}>
            {lines.map((_, index) => renderRow(index))}
          </div>
        )}
@@ -29,6 +29,10 @@ export function useWorkspaceTreeScrollPersistence<T extends HTMLElement>({
  }, [memoryKey, open, scrollRef]);

  return useCallback((event: UIEvent<T>) => {
+    // Only user-initiated scrolling is persisted: tree rebuilds reset the
+    // container to scrollTop 0 via script (isTrusted=false), and persisting
+    // that 0 would clobber the saved offset so restoration jumps back to top.
+    if (!event.nativeEvent.isTrusted) return;
    rememberWorkspaceTreeScroll(memoryKey, event.currentTarget.scrollTop);
  }, [memoryKey]);
 }
@@ -112,6 +112,7 @@ export function workspaceSplitTreeWidthFromPointer({
  railWidth = 0,
  treeMinWidth,
  previewMinWidth,
+  treeOnRight = false,
 }: {
  clientX: number;
  panelLeft: number;
@@ -119,7 +120,19 @@ export function workspaceSplitTreeWidthFromPointer({
  railWidth?: number;
  treeMinWidth: number;
  previewMinWidth: number;
+  treeOnRight?: boolean;
 }): number {
+  if (treeOnRight && typeof panelWidth === "number") {
+    // Tree width is the distance from the pointer to the panel's right edge.
+    // The rail still occupies its own column on the opposite side.
+    return clampWorkspaceSplitTreeWidth({
+      width: panelLeft + panelWidth - clientX,
+      panelWidth,
+      railWidth,
+      treeMinWidth,
+      previewMinWidth,
+    });
+  }
  return clampWorkspaceSplitTreeWidth({
    width: clientX - panelLeft - railWidth,
    panelWidth,
@@ -12,6 +12,7 @@ export interface WorkspaceTreeMemorySnapshot {
  scrollTop: number;
  dockTreeWidth: number | null;
  dockPreviewWidth: number | null;
+  recentPaths: string[];
 }

 type PersistedWorkspaceState = Omit<WorkspaceTreeMemorySnapshot, "openDirs" | "visitId"> & {
@@ -26,6 +27,7 @@ interface PersistedWorkspaceEnvelope {

 const STORAGE_KEY = "reasonix.workspaceState.v2";
 const MAX_PERSISTED_PROJECTS = 50;
+const MAX_RECENT_PATHS = 10;
 const workspaceTreeMemory = new Map<string, WorkspaceTreeMemorySnapshot>();
 let storageHydrated = false;
 let activeWorkspaceTreeKey = "";
@@ -42,6 +44,7 @@ function defaultSnapshot(visitId = 0): WorkspaceTreeMemorySnapshot {
    scrollTop: 0,
    dockTreeWidth: null,
    dockPreviewWidth: null,
+    recentPaths: [],
  };
 }

@@ -80,6 +83,9 @@ function hydrateWorkspaceTreeMemory(): void {
        dockPreviewWidth: typeof state.dockPreviewWidth === "number" && Number.isFinite(state.dockPreviewWidth) && state.dockPreviewWidth > 0
          ? state.dockPreviewWidth
          : null,
+        recentPaths: Array.isArray(state.recentPaths)
+          ? state.recentPaths.filter((path): path is string => typeof path === "string").slice(0, MAX_RECENT_PATHS)
+          : [],
      });
    }
  } catch {
@@ -103,6 +109,7 @@ function persistWorkspaceTreeMemory(recentKey: string): void {
          scrollTop: snapshot.scrollTop,
          dockTreeWidth: snapshot.dockTreeWidth,
          dockPreviewWidth: snapshot.dockPreviewWidth,
+          recentPaths: snapshot.recentPaths,
          updatedAt: key === recentKey ? now : 0,
        },
      }))
@@ -56,20 +56,25 @@ function clampStoredSidebarWidth(width: number): number {
  return Math.min(SIDEBAR_MAX_WIDTH, Math.max(CREATION_SIDEBAR_MIN_WIDTH, Math.round(width)));
 }

-export function clampRightDockPreviewWidth(width: number): number {
-  return Math.min(RIGHT_DOCK_MAX_WIDTH, Math.max(RIGHT_DOCK_PREVIEW_MIN_WIDTH, Math.round(width)));
+export function clampRightDockPreviewWidth(width: number, maxWidth = RIGHT_DOCK_MAX_WIDTH): number {
+  // Cap at maxWidth (which may be below the default maximum when the viewport
+  // is narrow) while never dropping below the applicable minimum.
+  return Math.min(Math.max(maxWidth, RIGHT_DOCK_PREVIEW_MIN_WIDTH), Math.max(RIGHT_DOCK_PREVIEW_MIN_WIDTH, Math.round(width)));
 }

-export function clampRightDockTreeWidth(width: number): number {
-  return Math.min(RIGHT_DOCK_TREE_MAX_WIDTH, Math.max(RIGHT_DOCK_TREE_MIN_WIDTH, Math.round(width)));
+export function clampRightDockTreeWidth(width: number, maxWidth = RIGHT_DOCK_TREE_MAX_WIDTH): number {
+  return Math.min(Math.max(maxWidth, RIGHT_DOCK_TREE_MIN_WIDTH), Math.max(RIGHT_DOCK_TREE_MIN_WIDTH, Math.round(width)));
 }

-export function clampCreationRightDockTreeWidth(width: number): number {
-  return Math.min(RIGHT_DOCK_TREE_MAX_WIDTH, Math.max(CREATION_RIGHT_DOCK_TREE_MIN_WIDTH, Math.round(width)));
+export function clampCreationRightDockTreeWidth(width: number, maxWidth = RIGHT_DOCK_TREE_MAX_WIDTH): number {
+  return Math.min(Math.max(maxWidth, CREATION_RIGHT_DOCK_TREE_MIN_WIDTH), Math.max(CREATION_RIGHT_DOCK_TREE_MIN_WIDTH, Math.round(width)));
 }

 function clampStoredRightDockTreeWidth(width: number): number {
-  return Math.min(RIGHT_DOCK_TREE_MAX_WIDTH, Math.max(CREATION_RIGHT_DOCK_TREE_MIN_WIDTH, Math.round(width)));
+  // Stored widths are validated again against the live viewport at load time
+  // (resolveWorkspacePanelWidth clamps to the chat pane's 400px floor), so
+  // persistence only guards the sane lower bound and integer form.
+  return Math.max(CREATION_RIGHT_DOCK_TREE_MIN_WIDTH, Math.round(width));
 }

 export function defaultSidebarWidth(): number {
@@ -202,21 +207,31 @@ export function clampTerminalHeight(height: number, viewportHeight: number): num
  return Math.min(max, Math.max(TERMINAL_MIN_HEIGHT, Math.round(height)));
 }

-function loadWorkspacePanelOpen(): boolean {
+function workspacePanelOpenStorageKey(workspaceRoot: string): string {
+  return workspaceRoot ? `${WORKSPACE_PANEL_OPEN_KEY}.${workspaceRoot}` : WORKSPACE_PANEL_OPEN_KEY;
+}
+
+export function loadWorkspacePanelOpen(workspaceRoot: string): boolean {
  if (typeof window === "undefined") return WORKSPACE_PANEL_DEFAULT_OPEN;
  try {
-    const raw = window.localStorage.getItem(WORKSPACE_PANEL_OPEN_KEY);
-    if (raw === null) return WORKSPACE_PANEL_DEFAULT_OPEN;
-    return raw !== "0";
+    const raw = window.localStorage.getItem(workspacePanelOpenStorageKey(workspaceRoot));
+    if (raw !== null) return raw !== "0";
+    // Migration: the legacy single global key predates per-project keys.
+    // When a project has no stored preference yet, seed it from the old
+    // global value so an upgrade does not flip a user's existing choice
+    // (e.g. they had the dock closed; first open of any project stays closed).
+    const legacyRaw = window.localStorage.getItem(WORKSPACE_PANEL_OPEN_KEY);
+    if (legacyRaw !== null) return legacyRaw !== "0";
+    return WORKSPACE_PANEL_DEFAULT_OPEN;
  } catch {
    return WORKSPACE_PANEL_DEFAULT_OPEN;
  }
 }

-export function saveWorkspacePanelOpen(open: boolean): void {
+export function saveWorkspacePanelOpen(open: boolean, workspaceRoot = ""): void {
  if (typeof window === "undefined") return;
  try {
-    window.localStorage.setItem(WORKSPACE_PANEL_OPEN_KEY, open ? "1" : "0");
+    window.localStorage.setItem(workspacePanelOpenStorageKey(workspaceRoot), open ? "1" : "0");
  } catch {
    /* ignore storage failures */
  }
@@ -250,7 +265,7 @@ export const useLayoutStore = create<LayoutState>((set) => ({
  sidebarWidth: loadSidebarWidth(),
  rightDockTreeWidth: loadRightDockTreeWidth(),
  rightDockPreviewWidth: loadRightDockPreviewWidth(),
-  workspacePanelOpen: loadWorkspacePanelOpen(),
+  workspacePanelOpen: loadWorkspacePanelOpen(""),
  workspacePanelMaximized: false,
  workspacePreviewActive: false,
  rightDockMode: "context",