FEAT(velero): configure velero

- for full k3s cluster backup
- Enable node-agent for PV file-system backups
- Add defaultVolumesToFsBackup configuration
- Optimize backup schedule (daily, 7-day retention)
- Exclude non-essential namespaces (postgresql-dev, harbor)
- Update Velero to v1.17.1
- Update velero-plugin-for-aws to v1.13.1

Full cluster disaster recovery backup now active.

postgresql/helm-values/postgresql.yaml

@@ -52,6 +52,10 @@ readReplicas:
     size: 20Gi
     storageClass: local-path
 
+  # Exclude read replicas from Velero backup (only backup primary)
+  podAnnotations:
+    backup.velero.io/backup-volumes-excludes: "data"
+
   # PostgreSQL configuration (must match primary for replication)
   extendedConfiguration: |
     max_connections = 200