chore: add documentation comments and stylecop rules

src/Application/TakeoutSaaS.Application/App/Tenants/Handlers/SearchTenantBillsQueryHandler.cs

@@ -15,13 +15,16 @@ public sealed class SearchTenantBillsQueryHandler(ITenantBillingRepository billi
 {
     public async Task<PagedResult<TenantBillingDto>> Handle(SearchTenantBillsQuery request, CancellationToken cancellationToken)
     {
+        // 1. 查询账单
         var bills = await billingRepository.SearchAsync(request.TenantId, request.Status, request.From, request.To, cancellationToken);
 
+        // 2. 排序与分页
         var ordered = bills.OrderByDescending(x => x.PeriodEnd).ToList();
         var page = request.Page <= 0 ? 1 : request.Page;
         var size = request.PageSize <= 0 ? 20 : request.PageSize;
         var items = ordered.Skip((page - 1) * size).Take(size).Select(x => x.ToDto()).ToList();
 
+        // 3. 返回分页结果
         return new PagedResult<TenantBillingDto>(items, page, size, ordered.Count);
     }
 }