Prefix fire-and-forget calls (PubSub.broadcast, Oban enqueue, Logger,
update_*, etc.) with `_ =` so dialyzer knows the return value is
intentionally discarded. Wrap a few if/case expressions whose
branches produce mixed types the same way.
No behavior changes — only explicit acknowledgement of discarded
returns.
Warnings: 242 → 88.
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>