FEAT(cnpg): add local-path-retain StorageClass

- for CNPG data protection

postgresql/manifests/cluster.yaml

@@ -10,9 +10,9 @@ spec:
   # Number of instances
   instances: 3  # 1 primary + 2 replicas for HA
 
-  # Storage configuration - using local-path
+  # Storage configuration - using local-path-retain for data protection
   storage:
-    storageClass: local-path
+    storageClass: local-path-retain
     size: 10Gi
 
   # Resource requests and limits

postgresql/manifests/storageclass.yaml

@@ -0,0 +1,7 @@
+apiVersion: storage.k8s.io/v1
+kind: StorageClass
+metadata:
+  name: local-path-retain
+provisioner: rancher.io/local-path
+reclaimPolicy: Retain
+volumeBindingMode: WaitForFirstConsumer