- Add metrics.py with pool utilization, task backlog, stuck rate, avg processing time, eval completion rate
- Add alerts.py with alert rules (pool utilization > 90%, task backlog > 50, stuck rate > 10%)
- Implement alert history and webhook notifications
- Add metrics and alerts APIs
- Add database migration for alert history table
- Add 11 unit tests for metrics, 10 unit tests for alerts, 8 integration tests
- Update migration tests to include new alert history table
All 853 tests passing.
