更新语言变化监听，明确i18n locale类型

src/main.ts

@@ -29,10 +29,9 @@ app.use(i18n)
 
 app.mount('#app')
 
-// 监听语言变化，更新i18n locale
 watch(
   () => languageStore.currentLanguage,
   (newLang) => {
-    i18n.global.locale.value = newLang
+    i18n.global.locale.value = newLang as 'en-us' | 'zh-cn' | 'zh-tw' | 'ja' | 'ko'
   }
 )