This commit addresses all issues reported in GitHub issue #485:
1. **SMART Status Recognition**
- Fix disk health check to accept both "PASSED" and "OK" status
- Previously only "PASSED" was recognized as healthy
- Location: internal/monitoring/monitor.go:1255
2. **ZFS Spare Device False Alerts**
- Skip ZFS SPARE devices unless they have actual errors
- SPARE devices are intentional and should not trigger alerts
- Updated in two locations:
- pkg/proxmox/zfs.go:154 (device filtering)
- internal/alerts/alerts.go:1077 (alert generation)
3. **Memory Display Granularity**
- Increase byte formatting precision from 0 to 1 decimal place
- Improves accuracy (e.g., "1.7 GB" instead of "1 GB" for 86% of 2GB)
- Location: frontend-modern/src/utils/format.ts:3
4. **Custom Alert Rules Evaluation**
- Add ReevaluateGuestAlert() method for proper threshold reevaluation
- Add comments explaining custom rules evaluation limitations
- Next poll cycle will properly clear stale alerts with new thresholds
Additional improvements:
- Fix ZFS pool alert locking to prevent deadlocks
- Prevent discovery service from running in mock mode
- Restore discovery service when exiting mock mode
Fixes#485
