refactor(frontend): modularize i18n architecture

frontend/src/main.ts

@@ -4,11 +4,14 @@ import router from './router'
 import './style.css'
 import App from './App.vue'
 import { preloadCriticalModules } from './utils/importRetry'
+import { createI18n } from './i18n'
 
 const app = createApp(App)
 const pinia = createPinia()
+const i18n = createI18n()
 
 app.use(pinia)
+app.use(i18n)
 app.use(router)
 
 // 预加载关键模块
@@ -23,4 +26,4 @@ app.config.errorHandler = (err: unknown, _instance, info) => {
   // 模块加载错误处理已移至 App.vue 的统一处理器中
 }
 
-app.mount('#app')
+app.mount('#app')