fix: round 10 critical fixes - WebSocket race, rate limiting, XSS protection, Caddyfile, and input validation

frontend/web/src/main.tsx

@@ -3,16 +3,8 @@ import ReactDOM from 'react-dom/client';
 import App from './App';
 import './index.css';
 
-// 注册 PWA Service Worker
-if ('serviceWorker' in navigator) {
-  window.addEventListener('load', () => {
-    navigator.serviceWorker.register('/sw.js').then((reg) => {
-      console.log('SW registered:', reg.scope);
-    }).catch((err) => {
-      console.log('SW registration failed:', err);
-    });
-  });
-}
+// Service Worker 注册已移至 hooks/usePWA.ts 中的 registerServiceWorker()，
+// 避免重复注册导致的竞态条件。App.tsx 会在初始化时调用 registerServiceWorker()。
 
 ReactDOM.createRoot(document.getElementById('root')!).render(
   <React.StrictMode>