test(ui-chat): pin the owner page branch-refusal notice

A refused branch now reports itself on the owner's own page: the Chat
injection writes the notice on the addressed Session and the composer bar
renders it as an alert, so the owner-visible change has an assertion at both
seams.

packages/client/ui-chat/tests/apply-inject.client.spec.tsx

@@ -294,7 +294,7 @@ describe('Chat inject API', () => {
     await b.runtime.dispose()
   })
 
-  it('states why a refused branch failed, on the Session it was asked of', async () => {
+  it('states why a refused branch failed on the owner page, on the Session it was asked of', async () => {
     /** The notice the addressed Session's composer bar consumes, as the page would show it. */
     const noticeOf = (sessionId: SessionId): string | undefined => {
       const entry = b.runtime.slots.entries('conversation.composer.bar')[0]
@@ -305,6 +305,9 @@ describe('Chat inject API', () => {
       return composer.hooks.notices.getSnapshot()?.text
     }
     const b = await bench()
+    // This page presents the owner's own browser session: the notice is an owner-visible change, not
+    // only a served-page one.
+    expect(b.runtime.ctx.remoteAccess.owner).toBe(true)
     const { injected } = b.chatViewApi(b.rootReference)
     // The Host's own message reaches the reader with the stable code beside it, and the Session it was
     // asked of is the one that shows it.

packages/client/ui-conversation/tests/input-bar.client.spec.tsx

@@ -1959,6 +1959,13 @@ describe('strips and variants', () => {
     }
   })
 
+  it('announces a refused branch from the machine store as an alert', () => {
+    const { view, shell } = bench()
+    // The Chat page reports a refused branch through this store; the bar renders the new copy.
+    act(() => { shell.notify('error', '未能完成分支：fork child rename failed') })
+    expect(view.getByRole('alert').textContent).toContain('未能完成分支：fork child rename failed')
+  })
+
   it('renders an information notice from the machine store as a status strip', () => {
     const { view, shell } = bench()
     act(() => { shell.notify('info', '命令完成了') })