feat(monitoring): add alerting stack and maintenance scripts

Medium priority stability improvements:

Alerting:
- Add vmalert for evaluating Prometheus alert rules
- Add alertmanager for alert routing and grouping
- Add alert-notifier service for Telegram/ntfy notifications
- Enable cadvisor scraping in prometheus config

Disk Monitoring:
- Add check-disk-space.sh for hourly disk monitoring
- Alert on 80% (warning) and 90% (critical) thresholds
- Auto-cleanup Docker when disk is critical
- Add com.manacore.disk-check.plist for LaunchD

Weekly Reports:
- Add weekly-report.sh for system health summary
- Includes: backup status, disk usage, container health,
  database stats, error log summary
- Runs every Sunday at 10 AM via LaunchD

Health Check Updates:
- Add checks for vmalert, alertmanager, alert-notifier

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

scripts/mac-mini/launchd/README.md

@@ -17,8 +17,11 @@ for f in *.plist; do launchctl load ~/Library/LaunchAgents/$f; done
 | Service | Description | Interval |
 |---------|-------------|----------|
 | `docker-startup` | Starts Docker containers on boot | At login |
-| `ensure-containers` | Detects and restarts stuck containers | Every 5 min |
+| `ensure-containers` | Detects and restarts stuck/crash-looping containers | Every 5 min |
 | `health-check` | Checks all services and sends alerts | Every 5 min |
+| `backup-databases` | PostgreSQL backup with daily/weekly rotation | Daily 3 AM |
+| `disk-check` | Monitors disk space, alerts on thresholds | Hourly |
+| `weekly-report` | Generates system health summary | Sunday 10 AM |
 | `ssd-check` | Monitors SSD health | Periodic |
 | `mana-stt` | Speech-to-text service (Whisper) | At login |
 | `mana-tts` | Text-to-speech service (Kokoro) | At login |