Fix Next.js security vulnerability by updating to 16.1.6

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

apps/docs/package.json

@@ -17,7 +17,7 @@
     "fumadocs-mdx": "^14.2.5",
     "fumadocs-ui": "^16.4.7",
     "lucide-react": "^0.562.0",
-    "next": "^16.1.3",
+    "next": "^16.1.5",
     "react": "^19.2.3",
     "react-dom": "^19.2.3",
     "server-only": "^0.0.1",