fix(canvas): restore left project sidebar

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

@@ -125,16 +125,12 @@ describe('AI Design Canvas page', () => {
     expect(screen.queryByText(/规格版本|编译器|生成策略|字段决策/)).not.toBeInTheDocument();
   });
 
-  it('renders the Workspace list as a full-height right Works rail on desktop', () => {
+  it('leaves desktop Workspace navigation to the shared left project sidebar', () => {
     setViewport(true);
     prepareWorkspace();
     render(<ImageCanvas />);
 
-    const rail = screen.getByTestId('image-workspace-works-rail');
-    expect(rail).toBeInTheDocument();
-    expect(within(rail).getByRole('heading', { name: '我的作品' })).toBeInTheDocument();
-    expect(within(rail).getByRole('button', { name: '打开作品 咖啡机新品主视觉' })).toBeInTheDocument();
-    expect(within(rail).getByRole('button', { name: '新建作品' })).toBeInTheDocument();
+    expect(screen.queryByTestId('image-workspace-works-rail')).not.toBeInTheDocument();
     expect(screen.queryByRole('button', { name: '作品' })).not.toBeInTheDocument();
   });
 
@@ -146,16 +142,19 @@ describe('AI Design Canvas page', () => {
     render(<ImageCanvas />);
 
     expect(screen.getByText(/制作方案已准备好，确认前仍可修改/)).toBeInTheDocument();
-    expect(within(screen.getByTestId('image-workspace-works-rail')).getByText('待确认')).toBeInTheDocument();
+    expect(screen.queryByTestId('image-workspace-works-rail')).not.toBeInTheDocument();
   });
 
-  it('opens the Works rail as a right sheet on compact layouts', () => {
+  it('opens the Works rail as a left sheet on compact layouts', () => {
     prepareWorkspace();
     render(<ImageCanvas />);
 
     fireEvent.click(screen.getByRole('button', { name: '作品' }));
-    expect(screen.getByTestId('image-workspace-works-rail')).toBeInTheDocument();
-    expect(within(screen.getByTestId('image-workspace-works-rail')).getByRole('heading', { name: '我的作品' })).toBeInTheDocument();
+    const rail = screen.getByTestId('image-workspace-works-rail');
+    expect(rail).toBeInTheDocument();
+    expect(within(rail).getByRole('heading', { name: '我的作品' })).toBeInTheDocument();
+    expect(rail.closest('[role="dialog"]')).toHaveClass('left-0');
+    expect(rail.closest('[role="dialog"]')).not.toHaveClass('right-0');
   });
 
   it('shows one unfinished assistant reply incrementally and replaces it with the canonical turn', async () => {