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.Infrastructure/Middleware/GlobalExceptionMiddleware.cs

@@ -13,6 +13,14 @@ public class GlobalExceptionMiddleware : IMiddleware
 {
     private readonly ILogger<GlobalExceptionMiddleware> _logger;
 
+    /// <summary>
+    /// JSON序列化选项（camelCase，与Controller保持一致）
+    /// </summary>
+    private static readonly JsonSerializerOptions JsonOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
+    };
+
     /// <summary>
     /// 构造函数
     /// </summary>
@@ -35,7 +43,7 @@ public class GlobalExceptionMiddleware : IMiddleware
         }
         catch (BusinessException ex)
         {
-            _logger.LogWarning(ex, "业务异常：{Message}", ex.Message);
+            _logger.LogWarning(ex, "业务异常：{Message}，状态码：{ResultCode}", ex.Message, ex.ResultCode);
             await HandleBusinessExceptionAsync(context, ex);
         }
         catch (Exception ex)
@@ -46,17 +54,17 @@ public class GlobalExceptionMiddleware : IMiddleware
     }
 
     /// <summary>
-    /// 处理业务异常
+    /// 处理业务异常（按业务状态码映射HTTP状态码）
     /// </summary>
     /// <param name="context">HTTP上下文</param>
     /// <param name="ex">业务异常</param>
     private static async Task HandleBusinessExceptionAsync(HttpContext context, BusinessException ex)
     {
         context.Response.ContentType = "application/json";
-        context.Response.StatusCode = StatusCodes.Status400BadRequest;
+        context.Response.StatusCode = GetHttpStatusCode(ex.ResultCode);
 
-        var response = BaseResponse<object>.Fail(ResultCode.FAIL,ex.Message);
-        var json = JsonSerializer.Serialize(response);
+        var response = BaseResponse<object>.Fail(ex.ResultCode, ex.Message);
+        var json = JsonSerializer.Serialize(response, JsonOptions);
 
         await context.Response.WriteAsync(json);
     }
@@ -71,9 +79,32 @@ public class GlobalExceptionMiddleware : IMiddleware
         context.Response.ContentType = "application/json";
         context.Response.StatusCode = StatusCodes.Status500InternalServerError;
 
-        var response = BaseResponse<object>.Fail("系统内部错误，请稍后重试");
-        var json = JsonSerializer.Serialize(response);
+        var response = BaseResponse<object>.Fail(ResultCode.GLOBAL_ERROR, "系统内部错误，请稍后重试");
+        var json = JsonSerializer.Serialize(response, JsonOptions);
 
         await context.Response.WriteAsync(json);
     }
+
+    /// <summary>
+    /// 根据业务状态码获取对应的HTTP状态码
+    /// </summary>
+    /// <param name="resultCode">业务状态码</param>
+    /// <returns>HTTP状态码</returns>
+    private static int GetHttpStatusCode(ResultCode resultCode)
+    {
+        return resultCode switch
+        {
+            ResultCode.DENY => StatusCodes.Status401Unauthorized,
+            ResultCode.FORBIDDEN => StatusCodes.Status403Forbidden,
+            ResultCode.NOT_FOUND => StatusCodes.Status404NotFound,
+            ResultCode.BAD_REQUEST => StatusCodes.Status400BadRequest,
+            ResultCode.PARAM_ERROR => StatusCodes.Status400BadRequest,
+            ResultCode.CONFLICT => StatusCodes.Status409Conflict,
+            ResultCode.UNPROCESSABLE_ENTITY => StatusCodes.Status422UnprocessableEntity,
+            ResultCode.TOO_MANY_REQUESTS => StatusCodes.Status429TooManyRequests,
+            ResultCode.BAD_GATEWAY => StatusCodes.Status502BadGateway,
+            ResultCode.SERVICE_UNAVAILABLE => StatusCodes.Status503ServiceUnavailable,
+            _ => StatusCodes.Status400BadRequest
+        };
+    }
 }

QYZH.InteractiveMagazine.Infrastructure/Middleware/ModelValidActionFilter.cs

@@ -24,7 +24,7 @@ public class ModelValidActionFilterAttribute : ActionFilterAttribute
                     errorDic.Add(key, errorStr);
                 }
             }
-            var result = new BaseResponse<Dictionary<string, string>>() { code = ResultCode.FAIL };
+            var result = new BaseResponse<Dictionary<string, string>>() { code = ResultCode.BAD_REQUEST };
 
             result.message = string.Join("|", errorDic.Select(e => e.Value).Distinct());
             result.result = errorDic;