refactor: redesign module system

src/modules/i18n.ts

@@ -0,0 +1,22 @@
+import { createI18n } from 'vue-i18n'
+import { UserModule } from '/~/types'
+
+// import i18n resources
+// https://vitejs.dev/guide/features.html#glob-import
+const messages = Object.fromEntries(
+  Object.entries(
+    import.meta.globEager('../../locales/*.json'))
+    .map(([key, value]) => {
+      return [key.slice(14, -5), value.default]
+    }),
+)
+
+export const install: UserModule = ({ app }) => {
+  const i18n = createI18n({
+    legacy: false,
+    locale: 'en',
+    messages,
+  })
+
+  app.use(i18n)
+}