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/Handlers/GetBillListQueryHandler.cs

@@ -0,0 +1,53 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Billings.Dto;
+using TakeoutSaaS.Application.App.Billings.Queries;
+using TakeoutSaaS.Domain.Tenants.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Results;
+
+namespace TakeoutSaaS.Application.App.Billings.Handlers;
+
+/// <summary>
+/// 获取账单列表查询处理器。
+/// </summary>
+public sealed class GetBillListQueryHandler(
+    ITenantBillingRepository billingRepository,
+    ITenantRepository tenantRepository)
+    : IRequestHandler<GetBillListQuery, PagedResult<BillDto>>
+{
+    /// <summary>
+    /// 处理获取账单列表请求。
+    /// </summary>
+    /// <param name="request">查询请求。</param>
+    /// <param name="cancellationToken">取消标记。</param>
+    /// <returns>分页账单列表。</returns>
+    public async Task<PagedResult<BillDto>> Handle(GetBillListQuery request, CancellationToken cancellationToken)
+    {
+        // 1. 分页查询账单
+        var (bills, total) = await billingRepository.SearchPagedAsync(
+            request.TenantId,
+            request.Status,
+            request.StartDate,
+            request.EndDate,
+            request.Keyword,
+            request.PageNumber,
+            request.PageSize,
+            cancellationToken);
+
+        // 2. 无数据直接返回
+        if (bills.Count == 0)
+        {
+            return new PagedResult<BillDto>([], request.PageNumber, request.PageSize, total);
+        }
+
+        // 3. 批量查询租户信息
+        var tenantIds = bills.Select(b => b.TenantId).Distinct().ToArray();
+        var tenants = await tenantRepository.FindByIdsAsync(tenantIds, cancellationToken);
+        var tenantDict = tenants.ToDictionary(t => t.Id, t => t.Name);
+
+        // 4. 映射 DTO
+        var result = bills.Select(b => b.ToDto(tenantDict.GetValueOrDefault(b.TenantId))).ToList();
+
+        // 5. 返回分页结果
+        return new PagedResult<BillDto>(result, request.PageNumber, request.PageSize, total);
+    }
+}