refactor: 统一业务异常处理，标准化结果码和错误响应

1.  新增并完善ResultCode枚举，补充标准HTTP状态码对应的业务状态码
2.  重构BusinessException，新增基于ResultCode的构造函数和ThrowIf扩展方法
3.  替换所有硬编码的HTTP状态码为统一的ResultCode枚举
4.  优化全局异常中间件，根据业务状态码映射对应HTTP状态码并规范化JSON响应
5.  修复OssImageHelper和AutoDotCodeConsumer中的OSS文件处理逻辑
6.  新增用户答题快照实体类
7.  清理废弃的宠物模块迁移脚本

QYZH.InteractiveMagazine.Models/Common/BusinessException.cs

@@ -1,3 +1,5 @@
+using QYZH.InteractiveMagazine.Models.Dto;
+
 namespace QYZH.InteractiveMagazine.Models.Common;
 
 /// <summary>
@@ -10,6 +12,11 @@ public class BusinessException : Exception
     /// </summary>
     public int Code { get; set; }
 
+    /// <summary>
+    /// 业务状态码
+    /// </summary>
+    public ResultCode ResultCode { get; set; } = ResultCode.FAIL;
+
     /// <summary>
     /// 无参构造函数
     /// </summary>
@@ -33,6 +40,18 @@ public class BusinessException : Exception
     public BusinessException(string message, int code) : base(message)
     {
         Code = code;
+        ResultCode = System.Enum.IsDefined(typeof(ResultCode), code) ? (ResultCode)code : ResultCode.FAIL;
+    }
+
+    /// <summary>
+    /// 构造函数（按业务状态码）
+    /// </summary>
+    /// <param name="message">异常消息</param>
+    /// <param name="resultCode">业务状态码</param>
+    public BusinessException(string message, ResultCode resultCode) : base(message)
+    {
+        ResultCode = resultCode;
+        Code = (int)resultCode;
     }
 
     /// <summary>
@@ -62,4 +81,15 @@ public class BusinessException : Exception
             throw new BusinessException(message);
         }
     }
+
+    /// <summary>
+    /// 条件抛出业务异常（带业务状态码）
+    /// </summary>
+    /// <param name="isTrue">是否触发</param>
+    /// <param name="message">异常消息</param>
+    /// <param name="resultCode">业务状态码</param>
+    public static void ThrowIf(bool isTrue, string message, ResultCode resultCode)
+    {
+        if (isTrue) throw new BusinessException(message, resultCode);
+    }
 }