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
...

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Author: dependabot[bot]