baseline: 保留 07 风格重写前的 Vue 前端原件

frontend/src/main.ts

@@ -0,0 +1,16 @@
+import { createApp } from 'vue'
+
+import App from './App.vue'
+import { router } from './router'
+import './styles/main.css'
+
+// 初始化暗色模式（优先本地存储，其次系统偏好）
+const savedTheme = localStorage.getItem('theme')
+const dark =
+  savedTheme === 'dark' ||
+  (!savedTheme && window.matchMedia('(prefers-color-scheme: dark)').matches)
+if (dark) {
+  document.documentElement.classList.add('dark')
+}
+
+createApp(App).use(router).mount('#app')