feat: use @tauri-apps/api/os for reliable platform detection (mac body class)

src/main.tsx

@@ -4,11 +4,16 @@ import App from './App'
 import './index.css'
 // 导入 Tauri API（自动绑定到 window.api）
 import './lib/tauri-api'
+import { platform as osPlatform } from '@tauri-apps/api/os'
 
 // 根据平台添加 body class，便于平台特定样式
-if (window.platform?.isMac) {
+osPlatform().then((p) => {
+  if (p === 'darwin') {
     document.body.classList.add('is-mac')
-}
+  }
+}).catch(() => {
+  // 忽略平台检测失败
+})
 
 ReactDOM.createRoot(document.getElementById('root')!).render(
   <React.StrictMode>