refactor: use nuxt compatiable 4 folder

app/composables/db.ts

@@ -0,0 +1,17 @@
+import { useStorage } from '@vueuse/core'
+import { lastDbUpdated, namespace } from '~/constants'
+import { db, initDb } from '~/utils/db'
+
+export function useIndexedDB() {
+  const dbUpdated = useStorage(`${namespace}:lastDbUpdated`, lastDbUpdated)
+
+  return {
+    init: async () => {
+      const count = await db.recipes.count()
+      if (!count || dbUpdated.value !== lastDbUpdated) {
+        await initDb()
+        dbUpdated.value = lastDbUpdated
+      }
+    },
+  }
+}