feat: 新增配额包/支付相关实体与迁移

App：新增 operation_logs/quota_packages/tenant_payments/tenant_quota_package_purchases 表

Identity：修正 Avatar 字段类型（varchar(256)->text），保持现有数据不变

src/Application/TakeoutSaaS.Application/App/Billings/Queries/GetTenantPaymentsQuery.cs

@@ -0,0 +1,15 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Billings.Dto;
+
+namespace TakeoutSaaS.Application.App.Billings.Queries;
+
+/// <summary>
+/// 获取租户支付记录查询。
+/// </summary>
+public sealed record GetTenantPaymentsQuery : IRequest<List<PaymentDto>>
+{
+    /// <summary>
+    /// 账单 ID（雪花算法）。
+    /// </summary>
+    public long BillId { get; init; }
+}