feat: finalize core modules and gateway

src/Application/TakeoutSaaS.Application/Storage/Abstractions/IFileStorageService.cs

@@ -0,0 +1,21 @@
+using System.Threading;
+using System.Threading.Tasks;
+using TakeoutSaaS.Application.Storage.Contracts;
+
+namespace TakeoutSaaS.Application.Storage.Abstractions;
+
+/// <summary>
+/// 文件存储应用服务抽象。
+/// </summary>
+public interface IFileStorageService
+{
+    /// <summary>
+    /// 通过服务端中转上传文件。
+    /// </summary>
+    Task<FileUploadResponse> UploadAsync(UploadFileRequest request, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// 生成前端直传凭证（预签名上传）。
+    /// </summary>
+    Task<DirectUploadResponse> CreateDirectUploadAsync(DirectUploadRequest request, CancellationToken cancellationToken = default);
+}