refactor(web): WebProtoBuffData 迁移到 ReferencePool 引用池模式

- readonly 字段改为属性（支持池回收后重新赋值）
- 移除有参构造函数，新增无参构造函数（ReferencePool new 约束）
- 新增 Create 工厂方法，通过 ReferencePool.Acquire 获取实例
- 新增 Clear 重写，取消未完成 Task 并清理引用

Author: AlianBlank

Runtime/Web/WebProtoBuffManager.WebProtoBufData.cs

@@ -1,4 +1,4 @@
-using System.Threading.Tasks;
+using System.Threading.Tasks;
 using GameFrameX.Runtime;
 using GameFrameX.Web.Runtime;
 
@@ -14,26 +14,43 @@ private sealed class WebProtoBufData : WebManager.WebData
             /// <summary>
             /// 获取请求任务的完成源，用于异步操作的控制和结果返回
             /// </summary>
-            public readonly TaskCompletionSource<WebBufferResult> Task;
+            public TaskCompletionSource<WebBufferResult> Task { get; private set; }
 
             /// <summary>
             /// 获取要发送的Protocol Buffer序列化后的字节数组数据
             /// </summary>
-            public readonly byte[] SendData;
+            public byte[] SendData { get; private set; }
 
             /// <summary>
-            /// 初始化Web ProtoBuf请求数据
+            /// 无参构造函数（ReferencePool 需要new约束）
             /// </summary>
-            /// <param name="url">请求URL</param>
-            /// <param name="sendData">要发送的Protocol Buffer序列化数据</param>
-            /// <param name="task">请求任务的完成源</param>
-            /// <param name="userData">用户自定义数据</param>
-            public WebProtoBufData(string url, byte[] sendData, TaskCompletionSource<WebBufferResult> task, object userData) : base(false, url, userData)
+            public WebProtoBufData() { }
+
+            /// <summary>
+            /// 创建Web ProtoBuf请求数据
+            /// </summary>
+            public static WebProtoBufData Create(string url, byte[] sendData, TaskCompletionSource<WebBufferResult> task, object userData)
             {
-                task.CheckNull(nameof(task));
-                SendData = sendData;
-                Task = task;
+                var data = ReferencePool.Acquire<WebProtoBufData>();
+                data.URL = url;
+                data.IsGet = false;
+                data.UserData = userData;
+                data.Task = task;
+                data.SendData = sendData;
+                return data;
+            }
+
+            public override void Clear()
+            {
+                if (Task != null)
+                {
+                    Task.TrySetCanceled();
+                    Task = null;
+                }
+
+                SendData = null;
+                base.Clear();
             }
         }
     }
-}
+}