- Add description and failed_check_count fields to incidents table
- Update handleIncident() to use configurable threshold (default 10 checks)
- Auto-generate incident description with:
- Number of consecutive failures
- Last error message/reason
- First failure timestamp
- Add API endpoints: GET/POST /api/settings/incident-threshold
- Add UI settings field to configure incident failure threshold
- Server: Get threshold from database settings (persistent across restarts)
- Default threshold: 10 consecutive failed checks per resource
- notificationService: Parse comma-separated emails from resource.email_to or global config; validate and send to each recipient
- API: Add PATCH /api/resources/:id/group endpoint to move resource between groups with validation and cache invalidation
- UI: Add group selector to edit modal; wire group change to PATCH endpoint; add help text for multi-email format