chore(deps): remove unused eslint-plugin-nuxt

The eslint-plugin-nuxt package is a Nuxt 2-era plugin that was not
referenced in any ESLint config. The project already uses @nuxt/eslint
which is the modern replacement.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -31,7 +31,6 @@
     "@vue/test-utils": "2.4.6",
     "esbuild": "0.27.3",
     "eslint": "9.39.4",
-    "eslint-plugin-nuxt": "4.0.0",
     "eslint-plugin-simple-import-sort": "12.1.1",
     "eslint-plugin-vue": "10.8.0",
     "nuxt": "4.3.1",