chore(deps): update nuxt core to v4

Author: renovate[bot]

package.json

@@ -27,14 +27,14 @@
     "@nuxtjs/html-validator": "^2.1.0",
     "@vueuse/nuxt": "14.0.0",
     "@vueuse/sound": "^2.1.3",
-    "nuxt": "^3.16.1",
+    "nuxt": "^4.0.0",
     "nuxt-og-image": "^5.1.1",
     "unplugin-vue-router": "^0.12.0",
     "vue": "^3.5.0",
     "vue-sonner": "^2.0.0"
   },
   "devDependencies": {
-    "@nuxt/test-utils": "3.21.0",
+    "@nuxt/test-utils": "4.1.0",
     "@playwright/test": "1.60.0",
     "@vue/test-utils": "2.4.6",
     "eslint": "9.39.5",