Update React Flight/Next.js RCE vulnerability

Updated dependencies to fix Next.js CVE vulnerabilities.

The fix-react2shell-next tool automatically updated the following packages to their secure versions:
- next
- react-server-dom-webpack
- react-server-dom-parcel  
- react-server-dom-turbopack

All package.json files have been scanned and vulnerable versions have been patched to the correct fixed versions based on the official React advisory.

Co-authored-by: Vercel <vercel[bot]@users.noreply.github.com>

Author: vercel[bot]

package.json

@@ -18,7 +18,7 @@
     "client-only": "^0.0.1",
     "clsx": "^2.1.1",
     "envin": "^1.1.10",
-    "next": "16.1.0-canary.9",
+    "next": "16.1.0-canary.12",
     "next-themes": "^0.4.6",
     "nextjs-toploader": "^3.9.17",
     "posthog-js": "^1.298.1",