feat: add public tenant packages listing and sort order

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

@@ -67,4 +67,9 @@ public sealed class TenantPackage : AuditableEntityBase
     /// 是否仍可售卖。
     /// </summary>
     public bool IsActive { get; set; } = true;
+
+    /// <summary>
+    /// 展示排序，数值越小越靠前。
+    /// </summary>
+    public int SortOrder { get; set; } = 0;
 }