feat(web): add plan mode controls

apps/web/tests/session-title.snapshot.ts

@@ -14,6 +14,7 @@ const PLUGINS: readonly (WebBootEntry & { dir: string })[] = [
   { id: '@deepseek-ai/dsh-client-ui-layout', dir: 'ui-layout', url: '/plugins/ui-layout.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-runtime'] },
   { id: '@deepseek-ai/dsh-client-ui-sidebar', dir: 'ui-sidebar', url: '/plugins/ui-sidebar.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-ui-layout'] },
   { id: '@deepseek-ai/dsh-client-ui-conversation', dir: 'ui-conversation', url: '/plugins/ui-conversation.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-ui-layout'] },
+  { id: '@deepseek-ai/dsh-client-ui-plan', dir: 'ui-plan', url: '/plugins/ui-plan.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-ui-conversation'] },
   { id: '@deepseek-ai/dsh-client-ui-trajectory', dir: 'ui-trajectory', url: '/plugins/ui-trajectory.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-ui-conversation'] },
 ]
 
@@ -77,7 +78,8 @@ function titleSurfaces(label: string): { sidebar: string; breadcrumb: string; do
   return { sidebar, breadcrumb, documentTitle: document.title }
 }
 
-it('projects initial and revised durable titles through the built eight-plugin fixture app', async () => {
+/** Boot the built fixture graph into the per-test root. */
+function bootFixtureApp(): void {
   const root = document.querySelector<HTMLElement>('#root')
   if (root === null) throw new Error('snapshot root missing')
   act(() => {
@@ -89,7 +91,10 @@ it('projects initial and revised durable titles through the built eight-plugin f
       executeBundle: (code) => { (0, eval)(code) },
     })
   })
+}
 
+it('projects initial and revised durable titles through the built nine-plugin fixture app', async () => {
+  bootFixtureApp()
   const projectLabel = await screen.findByText('fixture', {}, { timeout: 10_000 })
   const projectRow = projectLabel.closest<HTMLElement>('[role="treeitem"]')
   if (projectRow === null) throw new Error('fixture project row missing')
@@ -112,3 +117,53 @@ it('projects initial and revised durable titles through the built eight-plugin f
   await expect(`${JSON.stringify({ initial, revised }, null, 2)}\n`)
     .toMatchFileSnapshot('./snapshots/session-title.json')
 })
+
+it('snapshots pending and committed plan targets without implicit turn cancellation', async () => {
+  bootFixtureApp()
+  await screen.findByText('fixture', {}, { timeout: 10_000 })
+  fireEvent.click(screen.getByRole('button', { name: 'New session' }))
+  const select: HTMLSelectElement = await screen.findByRole('combobox', { name: '协作模式' }, { timeout: 10_000 })
+  const capture = (stage: string) => {
+    const chip = select.parentElement?.querySelector('span')?.textContent ?? ''
+    return {
+      stage,
+      label: chip,
+      value: select.value,
+      title: select.parentElement?.getAttribute('title') ?? '',
+      primary: screen.getByRole('button', { name: /^(发送|停止)$/ }).getAttribute('aria-label'),
+    }
+  }
+
+  const initial = capture('initial')
+  fireEvent.change(select, { target: { value: 'plan' } })
+  await screen.findByTitle(/计划模式将在下一次模型请求时生效/)
+  const planPending = capture('plan-pending')
+
+  const input = screen.getByPlaceholderText(/输入消息/)
+  fireEvent.change(input, { target: { value: 'commit plan' } })
+  fireEvent.click(screen.getByRole('button', { name: '发送' }))
+  await screen.findByTitle('当前为计划模式')
+  const planCommitted = capture('plan-committed')
+
+  fireEvent.change(select, { target: { value: 'default' } })
+  await screen.findByTitle(/默认模式将在下一次模型请求时生效/)
+  const defaultPendingWhileRunning = capture('default-pending-running')
+  fireEvent.click(screen.getByRole('button', { name: '停止' }))
+  await waitFor(() => { expect(screen.getByRole('button', { name: '发送' })).toBeTruthy() })
+  const defaultPendingAfterStop = capture('default-pending-stopped')
+
+  fireEvent.change(input, { target: { value: 'commit default' } })
+  fireEvent.click(screen.getByRole('button', { name: '发送' }))
+  await screen.findByTitle('当前为默认模式')
+  const defaultCommitted = capture('default-committed')
+  fireEvent.click(screen.getByRole('button', { name: '停止' }))
+
+  await expect(`${JSON.stringify({
+    initial,
+    planPending,
+    planCommitted,
+    defaultPendingWhileRunning,
+    defaultPendingAfterStop,
+    defaultCommitted,
+  }, null, 2)}\n`).toMatchFileSnapshot('./snapshots/plan-mode.json')
+})