fix(chat): reconcile reply recovery with continuous agent conversations

tests/unit/teacher-companion.test.tsx

@@ -468,7 +468,7 @@ describe('teacher presence and periodic guidance', () => {
     expect(screen.queryByTestId('teacher-invitation')).not.toBeInTheDocument();
   });
 
-  it('consumes the static greeting when consultation opens through the avatar and remembers it for the project', async () => {
+  it('consumes the static greeting when consultation opens through the avatar and remembers it across projects', async () => {
     const greeting = '有什么编程问题想一起讨论？';
     api.config.mockResolvedValue({ enabled: true, definition: { ...definition, welcome_message: greeting } });
     const view = await mount();
@@ -486,7 +486,7 @@ describe('teacher presence and periodic guidance', () => {
     const next = await mount();
     expect(screen.queryByTestId('teacher-invitation')).not.toBeInTheDocument();
     await act(async () => next.rerender(<Harness projectId="other" />));
-    expect(screen.getByTestId('teacher-invitation')).toHaveAttribute('data-bubble-kind', 'welcome');
+    expect(screen.queryByTestId('teacher-invitation')).not.toBeInTheDocument();
     expect(api.create).not.toHaveBeenCalled();
     expect(api.send).not.toHaveBeenCalled();
     expect(api.checkIn).not.toHaveBeenCalled();