Merge the concurrent selector adaptation; ui-model stays the model owner

The remote side re-merged master (i18n workflow round) and restored the
pre-architecture ModelSelector package with the Session-side state
machine. Reconciliation keeps that merge's master content and reasserts
this branch's model architecture: business state lives in ui-model's
shared per-session directory (ctx.models), not on Session/
ConversationSnapshot; the input.model seat entry and the /model popup
stay the two same-source entries; the history modelTarget piggyback stays
removed. The ui-model-selector package, its roster row, and its allowlist
entry go; the smoke-real roster names ui-model.

apps/web/tests/replay-round-trip.e2e.ts

@@ -105,6 +105,9 @@ describe('web e2e: fresh round trip through the real assembly', () => {
     // while the whole-region golden churns.
     await expect(page.getByRole('textbox').first().isVisible()).resolves.toBe(true)
     expect(await page.getByText('WEB_E2E_OK', { exact: false }).count()).toBeGreaterThanOrEqual(1)
+    await page.getByRole('button', {
+      name: '选择模型，当前 DeepSeek-V4-Flash',
+    }).waitFor({ timeout: 10_000 })
     const snapshot = await captureStableAria(page, '[class*="centerCol"]', scaffold.workspaceCwd)
     await compareOrRefreshGolden(UI_EXPECTED, snapshot, MODE)
   })

apps/web/tests/scaffold.ts

@@ -67,7 +67,11 @@ const CONFIG_PATH = join(REPO_ROOT, 'apps/cli/cordis.yml')
 // catch-all would leave resolveModelContext unroutable and compact-basic's
 // post-step pressure check would warn every step). The published
 // contextWindow keeps that pressure path provably inert for small fixtures.
-const REPLAY_PROVIDERS = [{ id: 'deepseek', name: 'DeepSeek', models: [{ id: 'deepseek-v4-flash', contextWindow: 128_000 }] }]
+const REPLAY_PROVIDERS = [{
+  id: 'deepseek',
+  name: 'DeepSeek',
+  models: [{ id: 'deepseek-v4-flash', name: 'DeepSeek-V4-Flash', contextWindow: 128_000 }],
+}]
 
 /** Repo-root .env → process.env for record mode (never overrides set vars); the smoke-real convention. */
 function loadRootEnv(): void {

apps/web/tests/seeded-history.e2e.ts

@@ -92,6 +92,12 @@ describe('web e2e: seeded history renders through cold resume', () => {
 
   it.skipIf(MODE === 'record')('matches the historical conversation aria golden', async () => {
     onTestFailed(() => saveFailureShot(page, 'web-e2e-seeded-aria'))
+    await page.getByRole('button', {
+      // This scenario deliberately leaves the LLM seam open to prove zero
+      // model calls. History still restores the selected id, but no catalog
+      // adapter exists to provide its presentation name.
+      name: '选择模型，当前 deepseek-v4-flash',
+    }).waitFor({ timeout: 10_000 })
     const snapshot = (await captureStableAria(page, '[class*="centerCol"]', scaffold.workspaceCwd))
       .split(SEED_ID).join('{{seededId}}')
     await compareOrRefreshGolden(UI_EXPECTED, snapshot, MODE)

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

@@ -17,6 +17,7 @@ const PLUGINS: readonly (WebBootEntry & { dir: string })[] = [
   { id: '@deepseek-ai/dsh-client-ui-settings-general', dir: 'ui-settings-general', url: '/plugins/ui-settings-general.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-ui-settings', '@deepseek-ai/dsh-client-locale'] },
   { id: '@deepseek-ai/dsh-client-ui-models', dir: 'ui-models', url: '/plugins/ui-models.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-ui-settings'] },
   { 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-model-selector', dir: 'ui-model-selector', url: '/plugins/ui-model-selector.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-ui-conversation'] },
   { id: '@deepseek-ai/dsh-client-ui-workspace', dir: 'ui-workspace', url: '/plugins/ui-workspace.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-runtime', '@deepseek-ai/dsh-client-ui-conversation', '@deepseek-ai/dsh-client-ui-sidebar'] },
   { id: '@deepseek-ai/dsh-client-ui-trajectory', dir: 'ui-trajectory', url: '/plugins/ui-trajectory.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-ui-conversation'] },
 ]
@@ -81,7 +82,7 @@ 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 nine-plugin fixture app', async () => {
+it('projects titles and routes the next turn through the selected model in the built fixture app', async () => {
   const root = document.querySelector<HTMLElement>('#root')
   if (root === null) throw new Error('snapshot root missing')
   act(() => {
@@ -116,6 +117,22 @@ it('projects initial and revised durable titles through the built nine-plugin fi
   await waitFor(() => { expect(document.title).toBe(`${revisedLabel} — DeepSeek Harness`) })
   const revised = titleSurfaces(revisedLabel)
 
+  const modelTrigger = await screen.findByRole('button', {
+    name: '选择模型，当前 DeepSeek-V4-Flash',
+  })
+  fireEvent.click(modelTrigger)
+  fireEvent.click(screen.getByRole('menuitemradio', { name: /GPT-5/ }))
+  await waitFor(() => { expect(modelTrigger.textContent).toBe('GPT-5') })
+
+  // fx-alpha starts in the running state. Selecting above is intentionally
+  // allowed for the next turn; stop the fixture's resident run before sending
+  // the route-report prompt.
+  fireEvent.click(screen.getByRole('button', { name: 'Stop generating' }))
+  const composer = await screen.findByPlaceholderText('Message the agent')
+  fireEvent.change(composer, { target: { value: 'report model' } })
+  fireEvent.keyDown(composer, { key: 'Enter' })
+  await screen.findByText('当前模型：openai/gpt-5', {}, { timeout: 10_000 })
+
   await expect(`${JSON.stringify({ initial, revised }, null, 2)}\n`)
     .toMatchFileSnapshot('./snapshots/session-title.json')
 })

apps/web/tests/smoke-real.e2e.ts

@@ -144,10 +144,14 @@ async function detailsTrack(page: Page): Promise<number> {
   return Number(cols.split(' ').pop()!.replace('px', ''))
 }
 
-// Readiness gate: `dsh web` serves ALL nine manifest plugins; until every UI
+// Readiness gate: `dsh web` serves all ten production manifest plugins; until every UI
 // plugin's client bundle exists and exports apply, the loader fail-louds and
 // the frame never appears.
-const UI_PLUGIN_DIRS = ['connection', 'runtime', 'ui-theme', 'locale', 'ui-layout', 'ui-sidebar', 'ui-settings', 'ui-settings-general', 'ui-models', 'ui-conversation', 'ui-question', 'ui-trajectory']
+const UI_PLUGIN_DIRS = [
+  'connection', 'runtime', 'ui-theme', 'locale', 'ui-layout', 'ui-sidebar',
+  'ui-settings', 'ui-settings-general', 'ui-models', 'ui-conversation',
+  'ui-model', 'ui-question', 'ui-trajectory',
+]
 const ROUND_DONE_MARKER = 'WEB_ROUND_DONE'
 const notReady = UI_PLUGIN_DIRS.filter((dir) => {
   const bundle = join(REPO_ROOT, 'packages/client', dir, 'lib/client.js')

apps/web/tests/snapshots/code-mode-round/ui.expected.md

@@ -26,4 +26,7 @@
 - combobox "Access mode":
   - option "Read-only" [selected]
   - option "Read-write"
+- button "选择模型，当前 deepseek-v4-flash":
+  - text: deepseek-v4-flash
+  - img
 - button "Send message" [disabled]

apps/web/tests/snapshots/fresh-round-trip/ui.expected.md

@@ -22,4 +22,7 @@
 - combobox "Access mode":
   - option "Read-only" [selected]
   - option "Read-write"
+- button "选择模型，当前 deepseek-v4-flash":
+  - text: deepseek-v4-flash
+  - img
 - button "Send message" [disabled]

apps/web/tests/snapshots/lifecycle-chrome/hero.expected.md

@@ -30,6 +30,9 @@
 - combobox "Access mode":
   - option "Read-only" [selected]
   - option "Read-write"
+- button "选择模型，当前 deepseek-v4-flash":
+  - text: deepseek-v4-flash
+  - img
 - button "Send message" [disabled]
 - text: 详情
 - button "关闭详情"

apps/web/tests/snapshots/lifecycle-chrome/reloaded.expected.md

@@ -18,4 +18,7 @@
 - combobox "Access mode":
   - option "Read-only" [selected]
   - option "Read-write"
+- button "选择模型，当前 deepseek-v4-flash":
+  - text: deepseek-v4-flash
+  - img
 - button "Send message" [disabled]

apps/web/tests/snapshots/live-interactions/cancel.expected.md

@@ -15,4 +15,7 @@
 - combobox "Access mode":
   - option "Read-only" [selected]
   - option "Read-write"
+- button "选择模型，当前 deepseek-v4-flash":
+  - text: deepseek-v4-flash
+  - img
 - button "Send message" [disabled]

apps/web/tests/snapshots/live-interactions/error-auth.expected.md

@@ -13,4 +13,7 @@
 - combobox "Access mode":
   - option "Read-only" [selected]
   - option "Read-write"
+- button "选择模型，当前 deepseek-v4-flash":
+  - text: deepseek-v4-flash
+  - img
 - button "Send message" [disabled]

apps/web/tests/snapshots/live-interactions/retry.expected.md

@@ -18,4 +18,7 @@
 - combobox "Access mode":
   - option "Read-only" [selected]
   - option "Read-write"
+- button "选择模型，当前 deepseek-v4-flash":
+  - text: deepseek-v4-flash
+  - img
 - button "Send message" [disabled]

apps/web/tests/snapshots/question-composer/answered.expected.md

@@ -24,4 +24,7 @@
 - combobox "Access mode":
   - option "Read-only" [selected]
   - option "Read-write"
+- button "选择模型，当前 deepseek-v4-flash":
+  - text: deepseek-v4-flash
+  - img
 - button "Send message" [disabled]

apps/web/tests/snapshots/seeded-history/ui.expected.md

@@ -27,4 +27,7 @@
 - combobox "Access mode":
   - option "Read-only" [selected]
   - option "Read-write"
+- button "选择模型，当前 deepseek-v4-flash":
+  - text: deepseek-v4-flash
+  - img
 - button "Send message" [disabled]

apps/web/tests/snapshots/steering/settled.expected.md

@@ -24,4 +24,7 @@
 - combobox "Access mode":
   - option "Read-only" [selected]
   - option "Read-write"
+- button "选择模型，当前 deepseek-v4-flash":
+  - text: deepseek-v4-flash
+  - img
 - button "Send message" [disabled]