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/Domain/TakeoutSaaS.Domain/Tenants/Entities/TenantPayment.cs

@@ -0,0 +1,50 @@
+using TakeoutSaaS.Domain.Tenants.Enums;
+using TakeoutSaaS.Shared.Abstractions.Entities;
+
+namespace TakeoutSaaS.Domain.Tenants.Entities;
+
+/// <summary>
+/// 租户支付记录。
+/// </summary>
+public sealed class TenantPayment : MultiTenantEntityBase
+{
+    /// <summary>
+    /// 关联的账单 ID。
+    /// </summary>
+    public long BillingStatementId { get; set; }
+
+    /// <summary>
+    /// 支付金额。
+    /// </summary>
+    public decimal Amount { get; set; }
+
+    /// <summary>
+    /// 支付方式。
+    /// </summary>
+    public PaymentMethod Method { get; set; }
+
+    /// <summary>
+    /// 支付状态。
+    /// </summary>
+    public PaymentStatus Status { get; set; }
+
+    /// <summary>
+    /// 交易号。
+    /// </summary>
+    public string? TransactionNo { get; set; }
+
+    /// <summary>
+    /// 支付凭证 URL。
+    /// </summary>
+    public string? ProofUrl { get; set; }
+
+    /// <summary>
+    /// 支付时间。
+    /// </summary>
+    public DateTime? PaidAt { get; set; }
+
+    /// <summary>
+    /// 备注信息。
+    /// </summary>
+    public string? Notes { get; set; }
+}