fix: use correct envVar format and enable platform services

- Fix envVar field names (key/value/description instead of name/default)
- Ghost: use MariaDB platform service instead of SQLite
- WordPress: use MariaDB platform service
- Nextcloud: use MariaDB + Redis platform services
- Gitea: use MariaDB platform service

apps/postgres/versions/1.0.0/config.json

@@ -2,17 +2,8 @@
   "image": "postgres:16-alpine",
   "port": 5432,
   "envVars": [
-    {
-      "name": "POSTGRES_PASSWORD",
-      "required": true
-    },
-    {
-      "name": "POSTGRES_USER",
-      "default": "postgres"
-    },
-    {
-      "name": "POSTGRES_DB",
-      "default": "postgres"
-    }
+    { "key": "POSTGRES_PASSWORD", "value": "", "description": "Superuser password", "required": true },
+    { "key": "POSTGRES_USER", "value": "postgres", "description": "Superuser name" },
+    { "key": "POSTGRES_DB", "value": "postgres", "description": "Default database name" }
   ]
 }