feat(windows): add mac-style project tabs

.planning/2026-08-17-project-tab-bar/findings.md

@@ -0,0 +1,6 @@
+# Findings
+
+- The macOS reference renders `projectSessions.openProjects` in a horizontal `projectTabBar` below the title area. Each tab has a folder icon, project name, active styling, and direct activation.
+- Windows already persists the same concept in `useWorkspaceTabsStore.projectTabs` and exposes `useFileSystemStore.switchToProject` plus `isSwitchingProject`.
+- Windows currently renders `TitleProjectMenu` inside the title bar; its dropdown already lists open projects and should remain for project-management actions.
+- `MainLayout` places `TitleBarWithSettings` immediately before the workbench and is the correct ownership boundary for a full-width tab strip.

.planning/2026-08-17-project-tab-bar/progress.md

@@ -0,0 +1,15 @@
+# Progress
+
+## 2026-08-17
+
+- Recorded the pre-existing dirty worktree and branch before editing.
+- Confirmed the macOS `WorkbenchView.projectTabBar` as the visual and interaction reference.
+- Confirmed Windows has project tab persistence and a switch action but no top-level project tab presentation.
+- User approved direct implementation using the macOS pattern.
+- Added and ran the red model test, then implemented `getProjectTabBarItems` and confirmed the green result.
+- Added and ran the red tab-bar contract test, then implemented the accessible tab bar component and confirmed the green result.
+- Mounted `ProjectTabBar` below `TitleBarWithSettings` in `MainLayout`.
+- Built the Windows Release application successfully with `scripts/build-windows.ps1 -Configuration Release`.
+- Started the updated Release executable and verified through WebView2 CDP that the Chinese "打开的项目" tab list renders six projects, switches `aria-selected`, and updates the title-bar project label.
+- Re-ran focused Bun tests (`2 pass`), related regression tests (`9 pass`), TypeScript typecheck, targeted lint, and `git diff --check` successfully.
+- Completed the five-axis implementation review with no Critical or Important findings; unrelated pre-existing changes remain unstaged.

.planning/2026-08-17-project-tab-bar/task_plan.md

@@ -0,0 +1,26 @@
+# Project Tab Bar
+
+## Goal
+
+Add a Mac-style project tab bar below the Windows title bar so projects open in the current window are visible and directly switchable.
+
+## Phases
+
+- [complete] Explore existing macOS and Windows project-session patterns.
+- [complete] Add failing model and interaction tests.
+- [complete] Implement the project tab bar and connect project switching.
+- [complete] Run frontend verification and live Windows checks.
+- [complete] Review and create one focused implementation commit.
+
+## Scope
+
+- Worktree: `D:\code\Lithe-IDEA-preview-0.3.0`
+- Branch: `fix/windows-new-window-blank`
+- Preserve all existing dirty files and stage only this task's files.
+- Keep the existing title-bar project dropdown and project persistence behavior.
+
+## Errors Encountered
+
+| Error | Attempt | Resolution |
+| --- | --- | --- |
+| No project-tab component exists in the Windows layout | 1 | Use the macOS `projectTabBar` structure as the reference and create a focused Windows presentation component. |

Sources/Lithe/Platform/MacOS/Community/LinuxDoAnonymousWebView.swift

@@ -28,9 +28,10 @@ final class LinuxDoAnonymousWebSession: ObservableObject {
         releaseTask = nil
     }
 
-    func releaseAfterInactivity() {
+    @discardableResult
+    func releaseAfterInactivity() -> Task<Void, Never> {
         releaseTask?.cancel()
-        releaseTask = Task { @MainActor [weak self] in
+        let task = Task { @MainActor [weak self] in
             guard let self else { return }
             try? await Task.sleep(nanoseconds: idleLifetimeNanoseconds)
             guard !Task.isCancelled else { return }
@@ -40,6 +41,8 @@ final class LinuxDoAnonymousWebSession: ObservableObject {
             webView = nil
             releaseTask = nil
         }
+        releaseTask = task
+        return task
     }
 
     deinit {

Tests/LitheTests/LinuxDoAnonymousWebSessionTests.swift

@@ -5,28 +5,25 @@ import Testing
 @MainActor
 struct LinuxDoAnonymousWebSessionTests {
     @Test
-    func shortPanelAbsenceKeepsTheCurrentWebView() async throws {
+    func shortPanelAbsenceKeepsTheCurrentWebView() async {
         let session = LinuxDoAnonymousWebSession(idleLifetimeNanoseconds: 50_000_000)
         let webView = WKWebView()
         session.webView = webView
 
-        session.releaseAfterInactivity()
+        let releaseTask = session.releaseAfterInactivity()
         session.resume()
-        try await Task.sleep(nanoseconds: 80_000_000)
+        await releaseTask.value
 
         #expect(session.webView === webView)
     }
 
     @Test
-    func inactiveSessionReleasesItsWebView() async throws {
+    func inactiveSessionReleasesItsWebView() async {
         let session = LinuxDoAnonymousWebSession(idleLifetimeNanoseconds: 20_000_000)
         session.webView = WKWebView()
 
-        session.releaseAfterInactivity()
-        let deadline = ContinuousClock.now + .seconds(1)
-        while session.webView != nil, ContinuousClock.now < deadline {
-            try await Task.sleep(for: .milliseconds(10))
-        }
+        let releaseTask = session.releaseAfterInactivity()
+        await releaseTask.value
 
         #expect(session.webView == nil)
     }

Tests/LitheTests/LitheCoreLogicTests.swift

@@ -3231,7 +3231,9 @@ struct EditorDocumentTests {
         source?.emit(DirectoryChangeBatch(gitStateMayHaveChanged: true))
         source?.emit(DirectoryChangeBatch(gitStateMayHaveChanged: true))
         source?.emit(DirectoryChangeBatch(gitStateMayHaveChanged: true))
-        let refreshed = await waitForWorkspaceObservation { refreshCount == 2 }
+        let refreshed = await waitForWorkspaceObservation(timeout: .seconds(15)) {
+            refreshCount == 2
+        }
 
         #expect(refreshed)
         #expect(refreshCount == 2)

docs/superpowers/plans/2026-08-17-project-tab-bar.md

@@ -0,0 +1,177 @@
+# Mac-Style Project Tab Bar Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:executing-plans to implement this plan task-by-task with verification checkpoints.
+
+**Goal:** Add a horizontal project tab bar below the Windows title bar so every project open in the current window is visible and can be activated with one click.
+
+**Architecture:** Keep project persistence and switching in the existing Zustand/file-system stores. Add a small pure model helper to normalize the active tab for deterministic tests, a focused `ProjectTabBar` presentation component for rendering and activation, and mount it from `MainLayout` directly below `TitleBarWithSettings`. The existing title-bar project dropdown remains unchanged as the project-management menu.
+
+**Tech Stack:** React 19, TypeScript, Zustand selectors, Base UI-compatible buttons, Tailwind semantic tokens, Bun tests, Vite Plus.
+
+---
+
+### Task 1: Normalize Project Tab Data
+
+**Files:**
+- Create: `windows/tauri/src/features/window/utils/project-tab-bar-model.ts`
+- Create: `windows/tauri/src/features/window/utils/project-tab-bar-model.test.ts`
+
+- [ ] **Step 1: Write the failing test**
+
+Add a fixture with two project tabs and assert that `getProjectTabBarItems` preserves order, marks only the first active project, and repairs an invalid multiple-active input by keeping the first active tab.
+
+```ts
+test("preserves project order and exposes one active tab", () => {
+  const result = getProjectTabBarItems([
+    { id: "a", name: "Alpha", path: "D:/alpha", isActive: true, lastOpened: 1 },
+    { id: "b", name: "Beta", path: "D:/beta", isActive: true, lastOpened: 2 },
+  ]);
+
+  expect(result.map((tab) => tab.name)).toEqual(["Alpha", "Beta"]);
+  expect(result.map((tab) => tab.isActive)).toEqual([true, false]);
+});
+```
+
+- [ ] **Step 2: Run the focused test and confirm the expected failure**
+
+Run from `windows/tauri`:
+
+```powershell
+bun test src/features/window/utils/project-tab-bar-model.test.ts
+```
+
+Expected: the test fails because `project-tab-bar-model.ts` does not exist yet.
+
+- [ ] **Step 3: Implement the minimal model helper**
+
+Implement `getProjectTabBarItems(projectTabs)` by finding the first `isActive` tab and mapping the input in its original order, setting `isActive` only for that ID while preserving the other display fields.
+
+- [ ] **Step 4: Run the focused test and confirm it passes**
+
+Run the same Bun test. Expected: 1 test passes, 0 failures.
+
+### Task 2: Build The Project Tab Bar
+
+**Files:**
+- Create: `windows/tauri/src/features/window/components/project-tab-bar.tsx`
+- Create: `windows/tauri/src/features/window/components/project-tab-bar.test.ts`
+
+- [ ] **Step 1: Write the failing component contract test**
+
+Add a source-level contract test that requires the component to expose `role="tablist"`, `role="tab"`, `aria-selected`, `isSwitchingProject`, and `switchToProject`. This protects the accessibility and switching contract without introducing a new renderer test dependency.
+
+- [ ] **Step 2: Run the focused test and confirm the expected failure**
+
+Run:
+
+```powershell
+bun test src/features/window/components/project-tab-bar.test.ts
+```
+
+Expected: the test fails because the component file does not exist yet.
+
+- [ ] **Step 3: Implement the component**
+
+Implement the component with these exact behaviors:
+
+```tsx
+const projectTabs = useWorkspaceTabsStore.use.projectTabs();
+const switchToProject = useFileSystemStore((state) => state.switchToProject);
+const isSwitchingProject = useFileSystemStore((state) => state.isSwitchingProject);
+const projects = getProjectTabBarItems(projectTabs);
+
+if (projects.length === 0) return null;
+
+return (
+  <div role="tablist" aria-label={t("titleProject.openProjects")}>
+    {projects.map((project) => (
+      <button
+        key={project.id}
+        type="button"
+        role="tab"
+        aria-selected={project.isActive}
+        disabled={isSwitchingProject || project.isActive}
+        title={project.path}
+        onClick={() => void switchToProject(project.id)}
+      >
+        {project.name}
+      </button>
+    ))}
+  </div>
+);
+```
+
+Use the existing `FolderOpenIcon`, semantic surface/border/selected tokens, fixed 30px tab height, horizontal overflow, visible focus styles, and truncated names. Do not add a native drag region or duplicate project-management actions.
+
+- [ ] **Step 4: Run the focused component contract test**
+
+Run the same Bun test. Expected: 1 test passes, 0 failures.
+
+### Task 3: Mount The Bar In The Workbench
+
+**Files:**
+- Modify: `windows/tauri/src/features/layout/components/main-layout.tsx`
+
+- [ ] **Step 1: Add the import and mount point**
+
+Import `ProjectTabBar` from the window feature and render `<ProjectTabBar />` immediately after `<TitleBarWithSettings />`, before the root-folder conditional. The component itself returns `null` when no project is open, preserving the welcome screen layout.
+
+- [ ] **Step 2: Run focused tests and typecheck**
+
+Run:
+
+```powershell
+bun test src/features/window/utils/project-tab-bar-model.test.ts src/features/window/components/project-tab-bar.test.ts
+bun run typecheck
+```
+
+Expected: all focused tests pass and TypeScript exits with code 0.
+
+### Task 4: Verify The User Workflow
+
+**Files:**
+- No additional source files.
+
+- [ ] **Step 1: Run lint and frontend build**
+
+```powershell
+bunx vp lint src/features/layout/components/main-layout.tsx src/features/window/components/project-tab-bar.tsx src/features/window/components/project-tab-bar.test.ts src/features/window/utils/project-tab-bar-model.ts src/features/window/utils/project-tab-bar-model.test.ts
+bun run build
+git diff --check
+```
+
+Expected: all commands exit 0. Existing dependency warnings are acceptable if they do not introduce errors.
+
+- [ ] **Step 2: Rebuild and launch Windows Release**
+
+Stop the current preview process, run `.\scripts\build-windows.ps1 -Configuration Release` from the repository root, and launch `windows/tauri/src-tauri/target/x86_64-pc-windows-msvc/release/lithe-windows.exe`.
+
+- [ ] **Step 3: Verify the live tab interaction through CDP**
+
+Open two projects in the current window, assert a visible `[role="tablist"]` contains both project names, click the inactive `[role="tab"]`, and assert its `aria-selected` becomes `true` while the previous tab becomes `false`. Confirm the title-bar project label changes to the newly active project.
+
+- [ ] **Step 4: Run the final focused checks**
+
+```powershell
+bun test src/features/window/utils/project-tab-bar-model.test.ts src/features/window/components/project-tab-bar.test.ts
+bun run typecheck
+git diff --check
+```
+
+Expected: all tests pass, typecheck passes, and no whitespace errors are reported.
+
+### Task 5: Review And Commit
+
+**Files:**
+- Stage only the new project-tab-bar source/tests, `main-layout.tsx`, and the task plan/progress files.
+
+- [ ] **Step 1: Inspect the task diff and run an independent review**
+
+Check `git diff` and confirm unrelated pre-existing changes remain unstaged. Resolve any Critical or Important review findings before committing.
+
+- [ ] **Step 2: Create one focused implementation commit**
+
+```powershell
+git add -- windows/tauri/src/features/layout/components/main-layout.tsx windows/tauri/src/features/window/components/project-tab-bar.tsx windows/tauri/src/features/window/components/project-tab-bar.test.ts windows/tauri/src/features/window/utils/project-tab-bar-model.ts windows/tauri/src/features/window/utils/project-tab-bar-model.test.ts .planning/2026-08-17-project-tab-bar/task_plan.md .planning/2026-08-17-project-tab-bar/findings.md .planning/2026-08-17-project-tab-bar/progress.md docs/superpowers/plans/2026-08-17-project-tab-bar.md
+git commit -m "feat: add mac-style project tabs"
+```

docs/superpowers/specs/2026-08-17-project-tab-bar-design.md

@@ -0,0 +1,28 @@
+# Mac-Style Project Tab Bar
+
+## Goal
+
+Show every project opened in the current Windows workbench in a compact tab bar below the title bar, matching the macOS workbench pattern. Clicking a tab activates that project immediately while the existing title-bar project menu remains the entry point for creating, opening, cloning, and selecting recent projects.
+
+## Design
+
+- Add a `ProjectTabBar` presentation component between `TitleBarWithSettings` and the workbench content in `MainLayout`.
+- Read project order and active state from `useWorkspaceTabsStore`; use `useFileSystemStore.switchToProject` for activation.
+- Render one semantic button per open project with its project badge/icon, name, active styling, and a full-path tooltip/accessible label.
+- Use a horizontal overflow container so the bar remains stable when many projects are open. Do not resize the title bar or use the tab bar as a native drag region.
+- Disable project buttons while `isSwitchingProject` is true, preserving the existing stale-switch protection.
+- Hide the bar when no project is open, so the welcome screen keeps its current vertical layout.
+- Preserve the existing `TitleProjectMenu` dropdown and all of its actions.
+
+## Accessibility And Visual Behavior
+
+- Use `role="tablist"` on the strip and `role="tab"` plus `aria-selected` on each project button.
+- Keep a visible focus ring and selected background/border using existing semantic design tokens.
+- Use the existing project badge/icon rules and Lucide-style folder icon; no new color palette or decorative artwork.
+- Keep the tab height and spacing fixed to prevent layout shift, and use text truncation with a tooltip for long names.
+
+## Testing
+
+- Add a pure model helper test that preserves project order and exposes exactly one active tab.
+- Add component-level source/behavior coverage for the tab button activation callback where the existing frontend test setup permits it.
+- Run focused Bun tests, typecheck, lint, frontend build, and a live Windows CDP check that opens two projects and activates the second tab.

windows/tauri/src/features/layout/components/main-layout.tsx

@@ -23,6 +23,7 @@ import { frontendTrace } from "@/utils/frontend-trace";
 import { recordStartupMilestone } from "@/features/bootstrap/startup-performance";
 import { getInternalTabDragData } from "@/features/tabs/utils/internal-tab-drag";
 import TitleBarWithSettings from "../../window/components/title-bar/title-bar";
+import { ProjectTabBar } from "../../window/components/project-tab-bar";
 import Footer from "./footer/footer";
 import { ResizablePane } from "./resizable-pane";
 import {
@@ -259,6 +260,7 @@ export function MainLayout() {
       )}
 
       <TitleBarWithSettings />
+      <ProjectTabBar />
 
       {rootFolderPath ? (
         <>

windows/tauri/src/features/window/components/project-tab-bar.test.ts

@@ -0,0 +1,11 @@
+import { expect, test } from "bun:test";
+
+test("project tab bar exposes accessible switchable project tabs", async () => {
+  const source = await Bun.file(new URL("./project-tab-bar.tsx", import.meta.url)).text();
+
+  expect(source).toContain('role="tablist"');
+  expect(source).toContain('role="tab"');
+  expect(source).toContain("aria-selected");
+  expect(source).toContain("isSwitchingProject");
+  expect(source).toContain("switchToProject");
+});