feat: 新增功能

- ChatManager：
  - 引入 System.Text.Json，用于将 agent thread 序列化与反序列化（示例：thread.Serialize(...) -> JsonSerializer.Deserialize -> agent.DeserializeThread）。
  - 增加示例：创建 OpenAIClient、初始化 agent、运行流式响应并处理更新。
  - 小幅格式和空行调整。
- AiChatService：
  - 为 Agent 发送接口 PostAgentSendAsync 增加注释与路由标记 HttpPost("ai-chat/agent/send")。

注意：提交中出现了硬编码的 API Key，请尽快改为从配置或机密管理中读取以防泄露。

Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Application/Services/Chat/AiChatService.cs

@@ -148,6 +148,9 @@ public class AiChatService : ApplicationService
         // 使用 ChatManager
     }
     
+    /// <summary>
+    /// Agent 发送消息
+    /// </summary>
     [HttpPost("ai-chat/agent/send")]
     public async Task PostAgentSendAsync()
     {

Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain/Managers/ChatManager.cs

@@ -1,5 +1,6 @@
 using System.ClientModel;
 using System.Reflection;
+using System.Text.Json;
 using Dm.util;
 using Microsoft.Agents.AI;
 using Microsoft.Extensions.AI;
@@ -15,6 +16,7 @@ public class ChatManager : DomainService
 {
     private readonly AiGateWayManager _aiGateWayManager;
     private readonly ILoggerFactory _loggerFactory;
+
     public ChatManager(AiGateWayManager aiGateWayManager, ILoggerFactory loggerFactory)
     {
         _aiGateWayManager = aiGateWayManager;
@@ -26,15 +28,16 @@ public class ChatManager : DomainService
         //token可以用户传进来
         // HttpClient.DefaultProxy = new WebProxy("127.0.0.1:8888");
         var modelId = "gpt-5.2-chat";
-        var client = new OpenAIClient(new ApiKeyCredential("xxx"), new OpenAIClientOptions
-        {
-            Endpoint = new Uri("https://yxai.chat/v1"),
-        });
+        var client = new OpenAIClient(new ApiKeyCredential("xxx"),
+            new OpenAIClientOptions
+            {
+                Endpoint = new Uri("https://yxai.chat/v1"),
+            });
         var agent = client.GetChatClient(modelId)
             .AsIChatClient() // Converts a native OpenAI SDK ChatClient into a Microsoft.Extensions.AI.IChatClient
-            .CreateAIAgent("你是一个专业的网页ai助手") ;
+            .CreateAIAgent("你是一个专业的网页ai助手");
+
 
-        
         var thread = agent.GetNewThread();
 
         var tools = GetTools();
@@ -43,7 +46,7 @@ public class ChatManager : DomainService
             Tools = tools.Select(x => (AITool)x).ToList(),
             ToolMode = ChatToolMode.Auto
         };
-        
+
         await foreach (var update in agent.RunStreamingAsync("联网搜索一下，奥德赛第一中学学生会会长是谁", thread,
                            new ChatClientAgentRunOptions(chatOptions)))
         {
@@ -71,6 +74,11 @@ public class ChatManager : DomainService
                 }
             }
         }
+
+
+        string serializedJson = thread.Serialize(JsonSerializerOptions.Web).GetRawText();
+        JsonElement reloaded = JsonSerializer.Deserialize<JsonElement>(serializedJson, JsonSerializerOptions.Web);
+        var newThread = agent.DeserializeThread(reloaded, JsonSerializerOptions.Web);
     }