refactor(user-journal): 重构用户期刊关联逻辑，移除枚举依赖并新增二维码功能

1.  删除不再使用的UserJournalTypeEnum枚举
2.  将UserJournal实体的Type字段改为int类型并移除枚举依赖
3.  移除BindJournal相关接口的类型参数校验和赋值逻辑
4.  新增二维码生成和上传功能，为用户期刊绑定QrCodeUrl字段
5.  修复UserAnswerTaskController的用户ID获取逻辑
6.  调整UserJournalQrCodeOutput的字段映射，替换QrCodeContent为QrCodeUrl

QYZH.InteractiveMagazine.Models/Dto/Journal/BindJournalDto.cs

@@ -17,10 +17,6 @@ public class BindJournalInput
     /// </summary>
     public long Id { get; set; }
 
-    /// <summary>
-    /// 关联类型: Read(已读), Favorite(收藏), Subscribe(订阅)，默认 Subscribe
-    /// </summary>
-    public string Type { get; set; } = UserJournalTypeEnum.Subscribe.ToString();
 }
 
 /// <summary>
@@ -121,10 +117,6 @@ public class CreateUserJournalQrCodeInput
     /// </summary>
     public long JournalId { get; set; }
 
-    /// <summary>
-    /// 关联类型: Read, Favorite, Subscribe，默认 Subscribe
-    /// </summary>
-    public string Type { get; set; } = UserJournalTypeEnum.Subscribe.ToString();
 }
 
 /// <summary>
@@ -201,7 +193,7 @@ public class UserJournalQrCodeOutput
     /// <summary>
     /// 二维码内容
     /// </summary>
-    public string QrCodeContent { get; set; } = string.Empty;
+    public string QrCodeUrl { get; set; } = string.Empty;
 
     /// <summary>
     /// 创建时间