Bump tailwindcss from 3.4.18 to 4.1.18

Bumps [tailwindcss](https://github.com/tailwindlabs/tailwindcss/tree/HEAD/packages/tailwindcss) from 3.4.18 to 4.1.18.
- [Release notes](https://github.com/tailwindlabs/tailwindcss/releases)
- [Changelog](https://github.com/tailwindlabs/tailwindcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/tailwindlabs/tailwindcss/commits/v4.1.18/packages/tailwindcss)

---
updated-dependencies:
- dependency-name: tailwindcss
  dependency-version: 4.1.18
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

packages/napcat-webui-frontend/package.json

@@ -84,7 +84,7 @@
     "react-window": "^1.8.11",
     "remark-gfm": "^4.0.0",
     "tailwind-variants": "^0.3.0",
-    "tailwindcss": "^3.4.17",
+    "tailwindcss": "^4.1.18",
     "zod": "^3.24.1"
   },
   "devDependencies": {