Revert "chore(frontend): upgrade next 16.1.6 → 16.2.6"

This reverts commit c76152c.

Author: mikevitelli

frontend/package.json

@@ -14,7 +14,7 @@
     "@sanity/client": "^7.17.0",
     "@upstash/redis": "^1.37.0",
     "@vercel/analytics": "^2.0.1",
-    "next": "^16.2.6",
+    "next": "16.1.6",
     "next-auth": "^5.0.0-beta.30",
     "react": "19.2.3",
     "react-dom": "19.2.3"