chore: add defu

Author: danielroe

package.json

@@ -19,6 +19,7 @@
     "@nuxtjs/html-validator": "^2.0.0",
     "@nuxtjs/plausible": "^1.0.3",
     "@unocss/nuxt": "^66.0.0",
+    "defu": "^6.1.4",
     "nitropack": "^2.10.4",
     "nuxt": "^3.14.159",
     "nuxt-og-image": "^5.0.0",