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

pgweb/manifests/secret.yaml

@@ -14,13 +14,13 @@ spec:
   data:
     - secretKey: database-url
       remoteRef:
-        key: databases/pgweb
+        key: pgweb
         property: DATABASE_URL
     - secretKey: auth-user
       remoteRef:
-        key: databases/pgweb
+        key: pgweb
         property: AUTH_USER
     - secretKey: auth-password
       remoteRef:
-        key: databases/pgweb
+        key: pgweb
         property: AUTH_PASSWORD