feat: 更新 index.html 和样式文件，优化样式导入和结构

src/plugins/vue-i18n/index.ts

@@ -0,0 +1,19 @@
+import { createI18n } from 'vue-i18n';
+
+/* https://github.com/intlify/bundle-tools/tree/main/packages/unplugin-vue-i18n#static-bundle-importing
+ * All i18n resources specified in the plugin `include` option can be loaded
+ * at once using the import syntax
+ */
+import messages from '@intlify/unplugin-vue-i18n/messages';
+console.debug(`messages :>> `, messages);
+
+export function setupVueI18n(app: import('vue').App) {
+  app.use(
+    // https://vue-i18n.intlify.dev/guide/essentials/started.html#registering-the-i18n-plugin
+    createI18n({
+      legacy: false, // you must set `false`, to use Composition API
+      locale: navigator.language,
+      messages,
+    }),
+  );
+}