Bump next from 15.5.10 to 15.5.18 in /client

Bumps [next](https://github.com/vercel/next.js) from 15.5.10 to 15.5.18.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Commits](vercel/next.js@v15.5.10...v15.5.18)

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.5.18
  dependency-type: direct:production
...

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

Author: dependabot[bot]

client/package-lock.json

@@ -28,7 +28,7 @@
     "framer-motion": "^12.23.24",
     "is-inside-container": "^1.0.0",
     "lucide-react": "^0.516.0",
-    "next": "15.5.10",
+    "next": "15.5.18",
     "react": "19.1.0",
     "react-dom": "19.1.0",
     "react-social-icons": "^6.25.0",