perf: 优化sse流式传输

Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain/AiChat/Impl/AzureRestChatService.cs

@@ -56,9 +56,14 @@ public class AzureRestChatService : IChatService
         httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {_options.ApiKey}");
         // 其他头信息如Content-Type在StringContent中设置
         
-        var content = new StringContent(jsonBody, Encoding.UTF8, "application/json");
+        // 构造 POST 请求
+        var request = new HttpRequestMessage(HttpMethod.Post, apiUrl);
+
+        // 设置请求内容（示例）
+        request.Content =new StringContent(jsonBody, Encoding.UTF8, "application/json");
+        
         // 发送POST请求
-        HttpResponseMessage response = await httpClient.PostAsync(apiUrl, content, cancellationToken);
+        HttpResponseMessage response = await httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
         // 确认响应成功
         response.EnsureSuccessStatusCode();