docs: 完善参数注释与StyleCop配置

src/Domain/TakeoutSaaS.Domain/Tenants/Repositories/ITenantBillingRepository.cs

@@ -1,6 +1,3 @@
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
 using TakeoutSaaS.Domain.Tenants.Entities;
 using TakeoutSaaS.Domain.Tenants.Enums;
 
@@ -50,6 +47,7 @@ public interface ITenantBillingRepository
     /// </summary>
     /// <param name="bill">账单实体。</param>
     /// <param name="cancellationToken">取消标记。</param>
+    /// <returns>异步任务。</returns>
     Task AddAsync(TenantBillingStatement bill, CancellationToken cancellationToken = default);
 
     /// <summary>
@@ -57,11 +55,13 @@ public interface ITenantBillingRepository
     /// </summary>
     /// <param name="bill">账单实体。</param>
     /// <param name="cancellationToken">取消标记。</param>
+    /// <returns>异步任务。</returns>
     Task UpdateAsync(TenantBillingStatement bill, CancellationToken cancellationToken = default);
 
     /// <summary>
     /// 保存变更。
     /// </summary>
     /// <param name="cancellationToken">取消标记。</param>
+    /// <returns>异步任务。</returns>
     Task SaveChangesAsync(CancellationToken cancellationToken = default);
 }