feat: 新增公告跳转链接字段 Url

- 在 AnnouncementAggregateRoot、AnnouncementLogDto、AnnouncementCacheDto 中新增 string? Url 属性，用于存储公告的跳转链接。
- 如果需要持久化到数据库，请同步添加对应的迁移/映射配置。

Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Application.Contracts/Dtos/Announcement/AnnouncementCacheDto.cs

@@ -14,4 +14,9 @@ public class AnnouncementCacheDto
     /// 公告日志列表
     /// </summary>
     public List<AnnouncementLogDto> Logs { get; set; } = new List<AnnouncementLogDto>();
+    
+    /// <summary>
+    /// 跳转链接
+    /// </summary>
+    public string? Url { get; set; }
 }

Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Application.Contracts/Dtos/Announcement/AnnouncementLogDto.cs

@@ -36,4 +36,9 @@ public class AnnouncementLogDto
     /// 公告类型（系统、活动）
     /// </summary>
     public AnnouncementTypeEnum Type{ get; set; }
+    
+    /// <summary>
+    /// 跳转链接
+    /// </summary>
+    public string? Url { get; set; }
 }

Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain/Entities/AnnouncementAggregateRoot.cs

@@ -49,4 +49,9 @@ public class AnnouncementAggregateRoot : FullAuditedAggregateRoot<Guid>
     /// 公告类型（系统、活动）
     /// </summary>
     public AnnouncementTypeEnum Type{ get; set; }
+
+    /// <summary>
+    /// 跳转链接
+    /// </summary>
+    public string? Url { get; set; }
 }