feat(spa): keep player in sync across next-round and document issue-180 flow

frontend/angular/src/app/features/player/player-shell.component.spec.ts

@@ -198,6 +198,30 @@ describe('PlayerShellComponent gameplay wiring', () => {
     expect(fetchMock).toHaveBeenCalledTimes(3);
   });
 
+  it('auto-refreshes player session to avoid host/player state desync between rounds', async () => {
+    vi.useFakeTimers();
+
+    const fetchMock: FetchMock = vi
+      .fn()
+      .mockResolvedValueOnce(jsonResponse(200, sessionDetailPayload('scoreboard', { roundQuestionId: null })))
+      .mockResolvedValueOnce(jsonResponse(200, sessionDetailPayload('lobby', { roundQuestionId: null })));
+
+    vi.stubGlobal('fetch', fetchMock);
+
+    const component = new PlayerShellComponent();
+    component.sessionCode = 'ABCD12';
+
+    await component.refreshSession();
+    expect(component.session?.session.status).toBe('scoreboard');
+
+    await vi.advanceTimersByTimeAsync(3100);
+
+    expect(fetchMock).toHaveBeenCalledTimes(2);
+    expect(component.session?.session.status).toBe('lobby');
+
+    component.ngOnDestroy();
+  });
+
   it('enters reconnecting state when network request fails while online', async () => {
     vi.stubGlobal('navigator', { onLine: true });