The file /home/project/src/hooks/useNetworkStatus.ts has been updated. Made 1 replacement. Here's the result of running `cat -n` on a snippet of the edited file: 50→ 51→ window.addEventListener('online', handleOnline); 52→ window.addEventListener('offline', handleOffline); 53→ 54→ // 检测慢网络(使用轻量级 DNS 预解析代替 HTTP 请求) 55→ const checkConnectionSpeed = async () => { 56→ if (!navigator.onLine) return; 57→ 58→ // 仅通过 navigator.connection API 检测(如果可用) 59→ const connection = (navigator as any).connection; 60→ if (connection) { 61→ setState(prev => ({ 62→ ...prev, 63→ isSlowConnection: connection.effectiveType === 'slow-2g' || connection.effectiveType === '2g' 64→ })); 65→ } 66→ // 如果不支持 Connection API,则不进行主动探测,避免产生大量 502 错误 67→ }; 68→ 69→ // 每60秒检测一次网络质量(降低频率) 70→ const interval = setInterval(checkConnectionSpeed, 60000); 71→ checkConnectionSpeed(); 72→ 73→ return () => { 74→ window.removeEventListener('online', handleOnline); 75→ window.removeEventListener('offline', handleOffline); 76→ clearInterval(interval);