fix(canvas): align fixed design sidebars

tests/unit/image-canvas-page.test.tsx

@@ -131,9 +131,9 @@ describe('AI Design Canvas page', () => {
     render(<ImageCanvas />);
 
     const historyRail = screen.getByTestId('image-workspace-history-rail');
-    expect(historyRail).toHaveClass('h-full', 'border-l');
-    expect(screen.getByTestId('image-workspace-header')).toHaveClass('h-12');
-    expect(screen.getByTestId('image-workspace-history-header')).toHaveClass('h-12');
+    expect(historyRail).toHaveClass('h-full', 'w-64', 'border-l');
+    expect(screen.getByTestId('image-workspace-header')).toHaveClass('h-10');
+    expect(screen.getByTestId('image-workspace-history-header')).toHaveClass('h-10');
     expect(within(historyRail).getByRole('heading', { name: '历史作品' })).toBeInTheDocument();
     expect(within(historyRail).queryByText('当前设计项目的制作记录')).not.toBeInTheDocument();
     expect(within(historyRail).getByText('还没有历史作品')).toBeInTheDocument();

tests/unit/main-layout-module-gate.test.tsx

@@ -7,18 +7,38 @@ import { useSettingsStore } from '@/stores/settings';
 const routeRenderMock = vi.hoisted(() => vi.fn());
 
 vi.mock('@/components/layout/Sidebar', () => ({
-  Sidebar: ({ hideOnCompact = false }: { hideOnCompact?: boolean }) => (
-    <aside data-testid="sidebar-stub" data-hide-on-compact={String(hideOnCompact)} />
+  Sidebar: ({ hideOnCompact = false, forceExpanded = false, sidebarPeekOpen = false, onSidebarPeekChange }: {
+    hideOnCompact?: boolean;
+    forceExpanded?: boolean;
+    sidebarPeekOpen?: boolean;
+    onSidebarPeekChange?: (open: boolean, source: 'toggle' | 'focus' | 'sidebar' | 'titlebar') => void;
+  }) => (
+    <aside
+      data-testid="sidebar-stub"
+      data-hide-on-compact={String(hideOnCompact)}
+      data-force-expanded={String(forceExpanded)}
+      data-peek-open={String(sidebarPeekOpen)}
+      data-has-peek-handler={String(Boolean(onSidebarPeekChange))}
+    />
   ),
 }));
 vi.mock('@/components/layout/TitleBar', () => ({
-  TitleBar: ({ integrated = false, overlay = false, showSidebarControls = true, pageTitle }: { integrated?: boolean; overlay?: boolean; showSidebarControls?: boolean; pageTitle?: string }) => (
+  TitleBar: ({ integrated = false, overlay = false, showSidebarControls = true, pageTitle, sidebarPeekOpen = false, onSidebarPeekChange }: {
+    integrated?: boolean;
+    overlay?: boolean;
+    showSidebarControls?: boolean;
+    pageTitle?: string;
+    sidebarPeekOpen?: boolean;
+    onSidebarPeekChange?: (open: boolean, source: 'toggle' | 'focus' | 'sidebar' | 'titlebar') => void;
+  }) => (
     <header
       data-testid="titlebar-stub"
       data-integrated={integrated ? 'true' : 'false'}
       data-overlay={overlay ? 'true' : 'false'}
       data-sidebar-controls={showSidebarControls ? 'true' : 'false'}
       data-page-title={pageTitle ?? ''}
+      data-peek-open={String(sidebarPeekOpen)}
+      data-has-peek-handler={String(Boolean(onSidebarPeekChange))}
     />
   ),
 }));
@@ -54,13 +74,19 @@ describe('MainLayout module isolation', () => {
   });
 
   it('uses the full-height workspace shell with the shared left project sidebar for AI painting', () => {
+    useSettingsStore.setState({ sidebarCollapsed: true });
     renderLayout('/image-canvas');
 
     expect(screen.getByTestId('main-content')).toHaveClass('basis-0', 'h-full', 'overflow-hidden', 'p-0');
     expect(screen.getByTestId('main-content')).not.toHaveClass('p-5', 'sm:p-6');
     expect(screen.getByTestId('titlebar-stub')).toHaveAttribute('data-overlay', 'true');
-    expect(screen.getByTestId('titlebar-stub')).toHaveAttribute('data-sidebar-controls', 'true');
+    expect(screen.getByTestId('titlebar-stub')).toHaveAttribute('data-sidebar-controls', 'false');
+    expect(screen.getByTestId('titlebar-stub')).toHaveAttribute('data-peek-open', 'false');
+    expect(screen.getByTestId('titlebar-stub')).toHaveAttribute('data-has-peek-handler', 'false');
     expect(screen.getByTestId('sidebar-stub')).toHaveAttribute('data-hide-on-compact', 'true');
+    expect(screen.getByTestId('sidebar-stub')).toHaveAttribute('data-force-expanded', 'true');
+    expect(screen.getByTestId('sidebar-stub')).toHaveAttribute('data-peek-open', 'false');
+    expect(screen.getByTestId('sidebar-stub')).toHaveAttribute('data-has-peek-handler', 'false');
   });
 
   it('does not overlay the local project initialization gate on AI hardware', () => {

tests/unit/title-bar.test.tsx

@@ -132,6 +132,18 @@ describe('TitleBar platform behavior', () => {
     expect(screen.getByTestId('titlebar-logo')).toBeInTheDocument();
   });
 
+  it('leaves the narrow Windows Canvas rail to the native window controls', () => {
+    window.electron.platform = 'win32';
+
+    render(<TitleBar integrated overlay showSidebarControls={false} />);
+
+    expect(screen.queryByTestId('titlebar-sidebar-toggle')).not.toBeInTheDocument();
+    expect(screen.queryByTestId('titlebar-logo')).not.toBeInTheDocument();
+    expect(screen.getByTitle('Minimize')).toBeInTheDocument();
+    expect(screen.getByTitle('Maximize')).toBeInTheDocument();
+    expect(screen.getByTitle('Close')).toBeInTheDocument();
+  });
+
   it('keeps an optional page title after the macOS traffic-light safe area', () => {
     window.electron.platform = 'darwin';
     useSettingsStore.setState({ sidebarCollapsed: true });