build(deps): bump next from 15.3.5 to 15.4.8 in /frontend (#12)

Bumps [next](https://github.com/vercel/next.js) from 15.3.5 to 15.4.8.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v15.3.5...v15.4.8)

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.4.8
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

frontend/package-lock.json

@@ -16,7 +16,7 @@
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "lucide-react": "^0.525.0",
-    "next": "15.3.5",
+    "next": "15.4.8",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
     "tailwind-merge": "^3.3.1",