Bump react-router and react-router-dom in /frontend

Bumps [react-router](https://github.com/remix-run/react-router/tree/HEAD/packages/react-router) to 7.12.0 and updates ancestor dependency [react-router-dom](https://github.com/remix-run/react-router/tree/HEAD/packages/react-router-dom). These dependencies need to be updated together.


Updates `react-router` from 7.9.6 to 7.12.0
- [Release notes](https://github.com/remix-run/react-router/releases)
- [Changelog](https://github.com/remix-run/react-router/blob/main/packages/react-router/CHANGELOG.md)
- [Commits](https://github.com/remix-run/react-router/commits/react-router@7.12.0/packages/react-router)

Updates `react-router-dom` from 7.9.6 to 7.12.0
- [Release notes](https://github.com/remix-run/react-router/releases)
- [Changelog](https://github.com/remix-run/react-router/blob/main/packages/react-router-dom/CHANGELOG.md)
- [Commits](https://github.com/remix-run/react-router/commits/react-router-dom@7.12.0/packages/react-router-dom)

---
updated-dependencies:
- dependency-name: react-router
  dependency-version: 7.12.0
  dependency-type: indirect
- dependency-name: react-router-dom
  dependency-version: 7.12.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

frontend/package.json

@@ -26,7 +26,7 @@
     "lucide-react": "^0.554.0",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",
-    "react-router-dom": "^7.9.6",
+    "react-router-dom": "^7.12.0",
     "socket.io-client": "^4.8.1",
     "sonner": "^2.0.7",
     "tailwind-merge": "^3.4.0"