test(timer): expose pause-over-midnight duration bug

Pause is tracked as pausedAt (TimeOfDay, ms since local midnight) and
paused duration is derived via the naive `clock - pausedAt`. When a pause
spans midnight the clock has wrapped to a small value while pausedAt is
still large, so the subtraction goes negative and every paused-duration
result is corrupted (runtimeState.start resume accumulation, and
getExpectedFinish/getCurrent/getRuntimeOffset in timerUtils).

Add two currently-failing tests that reproduce this:
- runtimeState: full start/pause/resume cycle where the pause crosses
  midnight, asserting pausedDuration and elapsed exclude the pause.
- timerUtils.getRuntimeOffset: over-midnight variant of the paused-offset
  case (the site carrying the "brakes when crossing midnight" TODO).

Both fail today (report ~ -86,100,000 instead of the real 5-minute pause)
and will pass once the pause math adopts the wrap-aware primitives
(timeCore.elapsedTime / epoch-based tracking).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0136N3FnyuUmLJbMNJiZd6YX

apps/server/src/services/__tests__/timerUtils.test.ts

@@ -975,6 +975,36 @@ describe('getRuntimeOffset()', () => {
     expect(absolute).toBe(25);
   });
 
+  it('paused time is delayed time when the pause spans midnight', () => {
+    const state = {
+      eventNow: {
+        id: '1',
+        timeStart: 23 * MILLIS_PER_HOUR, // 23:00
+        timeEnd: 1 * MILLIS_PER_HOUR, // 01:00
+        dayOffset: 0,
+      },
+      clock: 3 * MILLIS_PER_MINUTE, // 00:03 (after midnight)
+      timer: {
+        startedAt: 23 * MILLIS_PER_HOUR, // started on time at 23:00
+        current: 25, // still counting down
+        addedTime: 0,
+      },
+      _timer: {
+        pausedAt: 23 * MILLIS_PER_HOUR + 58 * MILLIS_PER_MINUTE, // 23:58, before midnight
+      },
+      rundown: {
+        actualStart: 23 * MILLIS_PER_HOUR,
+        plannedStart: 23 * MILLIS_PER_HOUR,
+        currentDay: 0,
+      },
+      _startDayOffset: 0,
+    } as RuntimeState;
+
+    // paused from 23:58 to 00:03 -> 5 minutes, regardless of the midnight wrap
+    const { absolute } = getRuntimeOffset(state);
+    expect(absolute).toBe(5 * MILLIS_PER_MINUTE);
+  });
+
   it('offset doesnt exist if we havent started', () => {
     const state = {
       clock: 78480789,

apps/server/src/stores/__tests__/runtimeState.test.ts

@@ -248,6 +248,53 @@ describe('mutation on runtimeState', () => {
       state = getState();
       expect(state.timer.elapsed).toBe(3 * MILLIS_PER_MINUTE);
     });
+
+    test('elapsed excludes a pause that spans midnight', async () => {
+      clearState();
+      // an event that runs over midnight (23:00 -> 01:00)
+      const event = {
+        ...mockEvent,
+        id: 'elapsed-pause-midnight',
+        timeStart: 23 * MILLIS_PER_HOUR,
+        timeEnd: 1 * MILLIS_PER_HOUR,
+        duration: 2 * MILLIS_PER_HOUR,
+      };
+      const mockRundown = makeRundown({
+        entries: { [event.id]: event },
+        order: [event.id],
+      });
+
+      await initRundown(mockRundown, {});
+      vi.runAllTimers();
+
+      const { metadata, rundown } = rundownCache.get();
+
+      // start before midnight
+      vi.setSystemTime('jan 1 23:50');
+      load(event, rundown, metadata);
+      start();
+
+      // 8 minutes of active running before we pause
+      vi.setSystemTime('jan 1 23:58');
+      update();
+      expect(getState().timer.elapsed).toBe(8 * MILLIS_PER_MINUTE);
+      pause();
+
+      // resume 5 minutes later, having crossed midnight (23:58 -> 00:03)
+      vi.setSystemTime('jan 2 00:03');
+      start();
+      let state = getState();
+      // the pause lasted 5 minutes, regardless of the midnight wrap
+      expect(state._timer.pausedDuration).toBe(5 * MILLIS_PER_MINUTE);
+      // elapsed must still exclude the paused time -> only the 8 active minutes
+      expect(state.timer.elapsed).toBe(8 * MILLIS_PER_MINUTE);
+
+      // 2 more active minutes after resume -> 10 minutes elapsed
+      vi.setSystemTime('jan 2 00:05');
+      update();
+      state = getState();
+      expect(state.timer.elapsed).toBe(10 * MILLIS_PER_MINUTE);
+    });
   });
 
   test('runtime offset', async () => {