feat: use nuxt 4 structure

nuxt.config.ts

@@ -1,5 +1,5 @@
-import { pwa } from './config/pwa'
+import { pwa } from './app/config/pwa'
-import { appDescription } from './constants/index'
+import { appDescription } from './app/constants/index'
 
 export default defineNuxtConfig({
   modules: [
@@ -75,5 +75,9 @@ export default defineNuxtConfig({
     },
   },
 
+  future: {
+    compatibilityVersion: 4,
+  },
+
   compatibilityDate: '2024-08-14',
 })