feat: 租户账单公告通知接口

src/Domain/TakeoutSaaS.Domain/Tenants/Entities/TenantAnnouncement.cs

@@ -0,0 +1,45 @@
+using TakeoutSaaS.Domain.Tenants.Enums;
+using TakeoutSaaS.Shared.Abstractions.Entities;
+
+namespace TakeoutSaaS.Domain.Tenants.Entities;
+
+/// <summary>
+/// 租户公告。
+/// </summary>
+public sealed class TenantAnnouncement : MultiTenantEntityBase
+{
+    /// <summary>
+    /// 公告标题。
+    /// </summary>
+    public string Title { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 公告正文（可为 Markdown/HTML，前端自行渲染）。
+    /// </summary>
+    public string Content { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 公告类型。
+    /// </summary>
+    public TenantAnnouncementType AnnouncementType { get; set; } = TenantAnnouncementType.System;
+
+    /// <summary>
+    /// 展示优先级，数值越大越靠前。
+    /// </summary>
+    public int Priority { get; set; } = 0;
+
+    /// <summary>
+    /// 生效时间（UTC）。
+    /// </summary>
+    public DateTime EffectiveFrom { get; set; } = DateTime.UtcNow;
+
+    /// <summary>
+    /// 失效时间（UTC），为空表示长期有效。
+    /// </summary>
+    public DateTime? EffectiveTo { get; set; }
+
+    /// <summary>
+    /// 是否启用。
+    /// </summary>
+    public bool IsActive { get; set; } = true;
+}

src/Domain/TakeoutSaaS.Domain/Tenants/Entities/TenantAnnouncementRead.cs

@@ -0,0 +1,24 @@
+using TakeoutSaaS.Shared.Abstractions.Entities;
+
+namespace TakeoutSaaS.Domain.Tenants.Entities;
+
+/// <summary>
+/// 租户公告已读记录。
+/// </summary>
+public sealed class TenantAnnouncementRead : MultiTenantEntityBase
+{
+    /// <summary>
+    /// 公告 ID。
+    /// </summary>
+    public long AnnouncementId { get; set; }
+
+    /// <summary>
+    /// 已读用户 ID（后台账号），为空表示租户级已读。
+    /// </summary>
+    public long? UserId { get; set; }
+
+    /// <summary>
+    /// 已读时间。
+    /// </summary>
+    public DateTime ReadAt { get; set; } = DateTime.UtcNow;
+}