postgresql: Add export volume claim.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Change-Id: I6c94084c8069179713a5b46d97e6cbb1fde1e477
diff --git a/postgresql/postgresql-export.yaml b/postgresql/postgresql-export.yaml
new file mode 100644
index 0000000..f5a484e
--- /dev/null
+++ b/postgresql/postgresql-export.yaml
@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: postgresql-export
+  namespace: system
+  labels:
+    name: postgresql-export
+    k8s-app: postgresql
+spec:
+  storageClassName: local-path
+  accessModes:
+    - ReadWriteOnce
+  resources:
+    requests:
+      storage: 200Gi