chore(frontend)(deps): bump zustand from 5.0.13 to 5.0.15 in /frontend

Bumps [zustand](https://github.com/pmndrs/zustand) from 5.0.13 to 5.0.15.
- [Release notes](https://github.com/pmndrs/zustand/releases)
- [Commits](pmndrs/zustand@v5.0.13...v5.0.15)

---
updated-dependencies:
- dependency-name: zustand
  dependency-version: 5.0.15
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

frontend/package.json

@@ -70,7 +70,7 @@
     "y-websocket": "^3.0.0",
     "yjs": "^13.6.30",
     "zod": "^4.4.3",
-    "zustand": "^5.0.12"
+    "zustand": "^5.0.15"
   },
   "devDependencies": {
     "@next/bundle-analyzer": "^16.1.6",