style(workspace): remove the embedded work preview title bar

tests/e2e/pi-coding-first-chat.spec.ts

@@ -2189,6 +2189,10 @@ test('work tab prepares the page automatically and keeps the student draft throu
   await expect(page.getByText('正在打开你的作品…', { exact: true })).toBeVisible();
   await electronApp.evaluate(() => { (globalThis as unknown as { __makelorePiFirstChatE2E: { workReady: boolean } }).__makelorePiFirstChatE2E.workReady = true; });
   await expect(page.getByRole('textbox', { name: '网页地址' })).toHaveValue('http://127.0.0.1:4173/');
+  await expect(page.getByTestId('agent-browser-panel')).toHaveAccessibleName('作品预览');
+  await expect(page.getByRole('heading', { name: '作品预览', exact: true })).toHaveCount(0);
+  await expect(page.getByRole('button', { name: '收起作品', exact: true })).toHaveCount(0);
+  await expect(page.getByTestId('agent-browser-viewport')).toBeVisible();
   await expect(page.getByText('正在打开你的作品…', { exact: true })).toHaveCount(0);
   // A manual address open must not permanently disable recovery checks.
   await page.getByRole('textbox', { name: '网页地址' }).fill('http://127.0.0.1:4173/');

tests/unit/agent-browser-panel.test.tsx

@@ -264,7 +264,13 @@ describe('AgentBrowserPanel', () => {
     const onOpenChange = vi.fn();
     const view = render(<AgentBrowserPanel projectId="project-a" open embedded onOpenChange={onOpenChange} />);
     await waitFor(() => expect(latestPresentation()).toMatchObject({ project_id: 'project-a', visible: true }));
+    expect(screen.getByRole('complementary', { name: '作品预览' })).toBeVisible();
+    expect(screen.queryByRole('heading', { name: '作品预览' })).not.toBeInTheDocument();
+    expect(screen.queryByRole('button', { name: '收起作品' })).not.toBeInTheDocument();
     expect(screen.getByRole('textbox', { name: '网页地址' })).toHaveValue('http://127.0.0.1:4173/');
+    expect(screen.getByRole('textbox', { name: '网页地址' })).toBeEnabled();
+    expect(screen.getByTestId('agent-browser-viewport')).toBeVisible();
+    expect(screen.getByTestId('agent-browser-viewport')).toHaveAccessibleName('作品画面');
 
     view.rerender(<AgentBrowserPanel projectId="project-a" open={false} embedded onOpenChange={onOpenChange} />);
     await waitFor(() => expect(latestPresentation()).toMatchObject({ visible: false }));