- Channel connectivity test: SMTP, webhook, mesh with real errors
- Rule test shows live data from feeds, not canned examples
- Near-miss detection: shows events filtered by threshold
- Three send actions: current conditions, example alert, live alert
- Rule status indicators: last fired, data source health
- All errors show actual error messages
- Disabled feed detection with clear warnings
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>