Add LiveView for real-time job monitoring dashboard:
- Subscribe to job:lifecycle PubSub topic for live updates
- Display health metrics (completed, failed, avg duration, active jobs)
- Show active operations with real-time updates
- Display problems section (stuck/failed job counts)
- Add router entry under /admin/monitoring
Tests verify PubSub subscription and basic rendering.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
