feat(worker): poll + reconcile stopwatch to server (admin stop/cancel)

apps/worker/src/screens/Stopwatch.test.tsx

@@ -4,6 +4,7 @@ import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
 import type { Activity, WorkSession } from '@solelog/shared';
 import Stopwatch from './Stopwatch';
+import { ApiError } from '../lib/api';
 import { useActivities } from '../api/activities';
 import {
   useActiveSessions,
@@ -247,4 +248,52 @@ describe('Stopwatch', () => {
 
     expect(await screen.findByText('Gepauzeerd — tik om te hervatten')).toBeInTheDocument();
   });
+
+  it('resets and shows a notice when the running session is stopped by the admin', async () => {
+    // Start with the session present so the screen adopts the running state.
+    mockedUseActiveSessions.mockReturnValue(
+      query<ReturnType<typeof useActiveSessions>>([activeSession()]),
+    );
+    const { rerender } = renderStopwatch();
+
+    // Confirm we are running (the Stop & Opslaan button is shown).
+    await screen.findByRole('button', { name: 'Stop & Opslaan' });
+
+    // The admin stops the session: the active list now no longer contains it.
+    mockedUseActiveSessions.mockReturnValue(query<ReturnType<typeof useActiveSessions>>([]));
+    const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } });
+    rerender(
+      <QueryClientProvider client={queryClient}>
+        <Stopwatch />
+      </QueryClientProvider>,
+    );
+
+    // The stopwatch resets to idle and shows the admin-stopped notice.
+    expect(
+      await screen.findByText('Deze sessie is door de beheerder gestopt.'),
+    ).toBeInTheDocument();
+    expect(screen.getByRole('button', { name: 'Start Stopwatch' })).toBeInTheDocument();
+    expect(screen.queryByRole('button', { name: 'Stop & Opslaan' })).not.toBeInTheDocument();
+  });
+
+  it('resets locally when stop fails with a 409 (already closed)', async () => {
+    const user = userEvent.setup();
+    stopMutate.mockImplementation((_id: number, opts?: { onError?: (e: unknown) => void }) => {
+      opts?.onError?.(new ApiError(409, 'Conflict'));
+    });
+    mockedUseActiveSessions.mockReturnValue(
+      query<ReturnType<typeof useActiveSessions>>([activeSession()]),
+    );
+    renderStopwatch();
+
+    const stopBtn = await screen.findByRole('button', { name: 'Stop & Opslaan' });
+    await user.click(stopBtn);
+
+    expect(stopMutate).toHaveBeenCalledTimes(1);
+    // The timer resets to idle despite the 409 (no stuck running state).
+    await waitFor(() =>
+      expect(screen.getByRole('button', { name: 'Start Stopwatch' })).toBeInTheDocument(),
+    );
+    expect(screen.queryByRole('button', { name: 'Stop & Opslaan' })).not.toBeInTheDocument();
+  });
 });