增强 MessageValidationStep 异常处理：1) 将 throw 替换为 PipelineException 2) 添加 input.Data 安全验证和字符串转换 3) 增强错误日志记录

src/X1.WebSocket/Pipeline/Steps/MessageValidationStep.cs

@@ -28,8 +28,22 @@ public class MessageValidationStep : IPipelineStep<WebSocketMessage, WebSocketMe
         }
         catch (Exception ex)
         {
-            _logger.LogError(ex, "Message validation failed for connection {ConnectionId}", input.ConnectionId);
-            throw;
+            var messageData = "null or empty";
+            if (input.Data != null && input.Data.Length > 0)
+            {
+                try
+                {
+                    messageData = System.Text.Encoding.UTF8.GetString(input.Data);
+                }
+                catch (Exception encodingEx)
+                {
+                    messageData = $"Encoding error: {encodingEx.Message}";
+                }
+            }
+            
+            _logger.LogError(ex, "Message validation failed for connection {ConnectionId}, message data: {MessageData}", 
+                input.ConnectionId, messageData);
+            throw new PipelineException($"Message validation failed: {ex.Message}", ex);
         }
     }