test(client): migrate the ui-conversation and web benches onto SlotTestRuntime

The five ui-conversation machinery specs (apply-inject, chat-apply,
chat-toolview-slot, service-orchestration, selection-survival — now .tsx)
and the web app/app-shell specs assemble through the runtime instead of
hand-built Context + SlotsService + fake-session scaffolding per suite.
Session behavior mocks are typed against ISession, so incomplete fakes
fail at compile time.

packages/client/web/package.json

@@ -31,6 +31,7 @@
   "devDependencies": {
     "@cordisjs/plugin-loader": "workspace:^",
     "@deepseek-ai/dsh-client-runtime": "workspace:^",
+    "@deepseek-ai/dsh-client-test-runtime": "workspace:^",
     "@deepseek-ai/dsh-invariants": "workspace:^",
     "@types/react": "~18.3.1",
     "@types/react-dom": "~18.3.0",

packages/client/web/tests/app-shell.spec.tsx

@@ -0,0 +1,61 @@
+// @vitest-environment jsdom
+/**
+ * App-shell assembly plugin on the real machinery: bare Context + production
+ * SlotsService + the test-runtime session/workspace doubles. Deliberately NOT
+ * mounted through SlotTestRuntime — its create() installs the capturing
+ * renderer and install() is boot-once; app-shell IS the production installer,
+ * so this bench hands it the uninstalled service exactly as boot does.
+ */
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { act, cleanup, render } from '@testing-library/react'
+import { Context } from 'cordis'
+import { SlotsService } from '@deepseek-ai/dsh-client-runtime/client'
+import { TestSessions, TestWorkspaces } from '@deepseek-ai/dsh-client-test-runtime'
+import type { Stabilizer } from '@deepseek-ai/dsh-client-test-runtime'
+import * as AppShell from '@deepseek-ai/dsh-client-web/src/app-shell.ts'
+
+afterEach(cleanup)
+
+const stabilize: Stabilizer = async (fn) => { await act(async () => { await fn() }) }
+
+async function bench() {
+  const ctx = new Context()
+  await ctx.plugin(SlotsService).await()
+  const slots = ctx.get('slots') as SlotsService
+  ctx.provide('sessions', new TestSessions(stabilize, ctx))
+  ctx.provide('workspaces', new TestWorkspaces(stabilize))
+  ctx.provide('layout', { openDetails: vi.fn(), closeDetails: vi.fn() })
+  const fiber = ctx.plugin({ inject: [...AppShell.inject], apply: AppShell.apply })
+  await fiber.await()
+  return { ctx, slots, fiber }
+}
+
+describe('app-shell assembly plugin', () => {
+  it('installs the renderer and provides the assembled appShell face', async () => {
+    const { ctx, slots } = await bench()
+    slots.register({ name: 'root' }, () => <div data-testid="root-probe" />)
+    const shell = ctx.get('appShell')
+    expect(shell).toBeDefined()
+    const view = render(<>{shell!.renderApp()}</>)
+    expect(view.getByTestId('root-probe')).toBeTruthy()
+  })
+
+  it('assembles once: repeated renderApp calls reuse the built closure', async () => {
+    const { ctx, slots } = await bench()
+    slots.register({ name: 'root' }, () => <div data-testid="root-probe" />)
+    const shell = ctx.get('appShell')!
+    const first = render(<>{shell.renderApp()}</>)
+    expect(first.getByTestId('root-probe')).toBeTruthy()
+    first.unmount()
+    // Second call rides the cached closure (renderApp ??=) and still renders.
+    const second = render(<>{shell.renderApp()}</>)
+    expect(second.getByTestId('root-probe')).toBeTruthy()
+  })
+
+  it('fiber dispose retracts the service and uninstalls the renderer', async () => {
+    const { ctx, slots, fiber } = await bench()
+    await stabilize(() => fiber.dispose())
+    expect(ctx.get('appShell')).toBeUndefined()
+    expect(() => slots.renderSlot('root', {})).toThrow('not installed')
+  })
+})

packages/client/web/tests/app.spec.tsx

@@ -0,0 +1,65 @@
+// @vitest-environment jsdom
+/**
+ * buildRenderApp on SlotTestRuntime: the fail-loud sessions precondition, the
+ * one ctx-level renderSlot('root') call, and the document-title projection
+ * arms over the real slot stack.
+ */
+import { afterEach, describe, expect, it } from 'vitest'
+import { cleanup, render } from '@testing-library/react'
+import { Context } from 'cordis'
+import { SlotTestRuntime } from '@deepseek-ai/dsh-client-test-runtime'
+import type { SessionId } from '@deepseek-ai/dsh-client-runtime/client'
+import { buildRenderApp } from '@deepseek-ai/dsh-client-web/src/app.tsx'
+
+let runtime: SlotTestRuntime | undefined
+
+afterEach(async () => {
+  cleanup()
+  await runtime?.dispose()
+  runtime = undefined
+  document.title = ''
+})
+
+async function bench() {
+  runtime = await SlotTestRuntime.create()
+  await runtime.root.declare({}, () => <div data-testid="frame" />)
+  return { runtime, renderApp: buildRenderApp({ ctx: runtime.ctx }) }
+}
+
+describe('buildRenderApp', () => {
+  it('fails loud when the sessions service is unavailable', () => {
+    expect(() => buildRenderApp({ ctx: new Context() })).toThrow('sessions service unavailable')
+  })
+
+  it('renders the root slot tree through the one ctx-level renderSlot call', async () => {
+    const b = await bench()
+    const view = render(<>{b.renderApp()}</>)
+    expect(view.getByTestId('frame')).toBeTruthy()
+  })
+
+  it('projects the current session durable title and falls back to the product title', async () => {
+    document.title = 'Product'
+    const b = await bench()
+    render(<>{b.renderApp()}</>)
+    // No current session: the product title stands.
+    expect(document.title).toBe('Product')
+    await b.runtime.sessions.add({ id: 's1', summary: { title: 'First' } })
+    expect(document.title).toBe('First — Product')
+    await b.runtime.sessions.setCurrent(undefined)
+    expect(document.title).toBe('Product')
+    // A session without a durable title keeps the product title.
+    await b.runtime.sessions.add({ id: 's2' })
+    expect(document.title).toBe('Product')
+  })
+
+  it('a current id without a list row falls back (selection/list arbitration transient)', async () => {
+    document.title = 'Product'
+    const b = await bench()
+    await b.runtime.sessions.add({ id: 's1', summary: { title: 'First' } })
+    render(<>{b.renderApp()}</>)
+    expect(document.title).toBe('First — Product')
+    b.runtime.sessions.list.update((draft) => { draft.current = 'ghost' as SessionId })
+    await b.runtime.flush()
+    expect(document.title).toBe('Product')
+  })
+})