httpx 连接超时：5000 毫秒后连接超时

解决方案

1. 85% 成功率 增加超时时间并添加重试机制

   client = httpx.AsyncClient(timeout=10.0)
   for i in range(3):
       try:
           response = await client.get(url)
           break
       except httpx.ConnectTimeout:
           await asyncio.sleep(1)

2. 90% 成功率 检查网络连接和服务可用性

   ping example.com
   curl -v http://example.com