feat(notify-bridge): phase 8 - integration and wiring

Wire all components into a working application:
- Scheduler service: APScheduler loads enabled trackers, polls at intervals
- Watcher service: orchestrates poll -> detect -> notify flow
  - Eagerly loads DB data, then creates aiohttp session for provider
  - Saves tracker state after each poll
  - Logs events to EventLog table
  - Dispatches notifications to targets with template rendering
- Manual trigger endpoint: POST /api/trackers/{id}/trigger
- Scheduler starts on app lifespan startup
- Full end-to-end flow verified: server starts cleanly

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/server/src/notify_bridge_server/api/trackers.py

@@ -102,3 +102,18 @@ async def delete_tracker(
         raise HTTPException(status_code=404, detail="Tracker not found")
     await session.delete(tracker)
     await session.commit()
+
+
+@router.post("/{tracker_id}/trigger")
+async def trigger_tracker(
+    tracker_id: int,
+    user: User = Depends(get_current_user),
+    session: AsyncSession = Depends(get_session),
+):
+    tracker = await session.get(Tracker, tracker_id)
+    if not tracker or tracker.user_id != user.id:
+        raise HTTPException(status_code=404, detail="Tracker not found")
+
+    from ..services.watcher import check_tracker
+    result = await check_tracker(tracker_id)
+    return result