fix: 修正 TDesign Message/Dialog 样式导入路径

使用 css.mjs，修复 Vite 无法解析 css.js 导致白屏。

src/main.js

@@ -3,8 +3,8 @@ import App from './App.vue'
 import router from './router'
 import { setupStore } from './stores'
 import './styles/prototype.css'
-import 'tdesign-vue-next/es/message/style/css.js'
-import 'tdesign-vue-next/es/dialog/style/css.js'
+import 'tdesign-vue-next/es/message/style/css.mjs'
+import 'tdesign-vue-next/es/dialog/style/css.mjs'
 
 const app = createApp(App)
 setupStore(app)