backup & DR: add alerting, fix rotation, secure MySQL password, add runbooks
Phase 1: Add 12 PrometheusRules for backup health alerting
- PostgreSQL, MySQL, Vault, Vaultwarden, Redis staleness + never-succeeded alerts
- CSIDriverCrashLoop alert for nfs-csi/iscsi-csi namespaces
- Generic BackupCronJobFailed alert
Phase 2: Fix backup rotation
- etcd: timestamped snapshots instead of overwriting single file
- Redis: timestamped RDB files with 7-day retention purge
- PostgreSQL: retention increased from 7 to 14 days
Phase 3: Fix MySQL password exposure
- Move root password from command line arg to MYSQL_PWD env var via secretKeyRef
Phase 5: Add restore runbooks
- PostgreSQL, MySQL, Vault, etcd, Vaultwarden, full cluster rebuild