Update dependencies and remove unused build config

Added 'client-only' and 'server-only' packages to site dependencies in package.json. Removed the unused 'build.output' property from objectdocs.json for cleanup.

Author: hotlong

objectdocs.json

@@ -13,9 +13,6 @@
       { "code": "zh-CN", "name": "简体中文" }
     ]
   },
-  "build": {
-    "output": ""
-  },
   "branding": {
     "logo": {
       "text": "ObjectStack"

packages/site/package.json

@@ -15,6 +15,7 @@
     "@types/node": "^25.0.8",
     "@types/react": "^19.2.8",
     "autoprefixer": "^10.4.23",
+    "client-only": "^0.0.1",
     "dotenv": "^16.4.5",
     "fumadocs-core": "^16.4.7",
     "fumadocs-mdx": "^14.2.5",
@@ -24,6 +25,7 @@
     "postcss": "^8.5.6",
     "react": "^19.2.3",
     "react-dom": "^19.2.3",
+    "server-only": "^0.0.1",
     "tailwindcss": "^4.1.18",
     "typescript": "^5.9.3"
   }