build(deps): bump shadcn from 4.7.0 to 4.12.0 in /web/frontend

Bumps [shadcn](https://github.com/shadcn-ui/ui/tree/HEAD/packages/shadcn) from 4.7.0 to 4.12.0.
- [Release notes](https://github.com/shadcn-ui/ui/releases)
- [Changelog](https://github.com/shadcn-ui/ui/blob/main/packages/shadcn/CHANGELOG.md)
- [Commits](https://github.com/shadcn-ui/ui/commits/shadcn@4.12.0/packages/shadcn)

---
updated-dependencies:
- dependency-name: shadcn
  dependency-version: 4.12.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

web/frontend/package.json

@@ -42,7 +42,7 @@
     "rehype-raw": "^7.0.0",
     "rehype-sanitize": "^6.0.0",
     "remark-gfm": "^4.0.1",
-    "shadcn": "^4.7.0",
+    "shadcn": "^4.12.0",
     "sonner": "^2.0.7",
     "tailwind-merge": "^3.5.0",
     "tailwindcss": "^4.3.0",