REFACTOR(secrets): flatten Vault paths

- Change secret paths from <category>/<app> to <app>
- databases/postgresql → postgresql
- databases/minio → minio
- databases/pgweb → pgweb
- cluster-infrastructure/velero → velero

minio/manifests/secret.yaml

@@ -14,17 +14,17 @@ spec:
   data:
     - secretKey: root-user
       remoteRef:
-        key: databases/minio
+        key: minio
         property: ROOT_USER
     - secretKey: root-password
       remoteRef:
-        key: databases/minio
+        key: minio
         property: ROOT_PASSWORD
     - secretKey: rootUser
       remoteRef:
-        key: databases/minio
+        key: minio
         property: ROOT_USER
     - secretKey: rootPassword
       remoteRef:
-        key: databases/minio
+        key: minio
         property: ROOT_PASSWORD