feat: Implement direct upload functionality for desktop client releases

- Added new endpoints for initiating and completing direct uploads of desktop client packages.
- Introduced request and response structures for direct upload operations.
- Enhanced the upload process to support SHA256 and Content-MD5 validation.
- Updated the frontend to reflect changes in upload button states and progress indicators.
- Modified object storage clients to support presigned PUT URLs with content type and MD5 headers.
- Added tests for direct upload functionality and ensured existing upload processes remain intact.

server/internal/shared/swagger/descriptions.go

@@ -100,7 +100,9 @@ var routeDocs = map[string]routeDoc{
 
 	// --- Ops：桌面客户端版本 ---
 	"GET /api/ops/desktop-client/releases":                                        {"桌面客户端版本列表", "分页查询桌面客户端版本配置。"},
-	"POST /api/ops/desktop-client/releases/upload":                                {"上传桌面客户端包（兼容）", "兼容旧版单请求 Multipart 上传；新版前端使用分片上传。"},
+	"POST /api/ops/desktop-client/releases/upload":                                {"上传桌面客户端包（兼容）", "兼容旧版单请求 Multipart 上传。"},
+	"POST /api/ops/desktop-client/releases/direct-upload":                         {"初始化客户端包 OSS 直传", "校验文件信息并生成浏览器直传 OSS 的短期 PUT 签名 URL。"},
+	"POST /api/ops/desktop-client/releases/direct-upload/complete":                {"完成客户端包 OSS 直传", "校验直传对象是否存在、大小是否匹配，并返回 Object Key、文件大小和 SHA256。"},
 	"POST /api/ops/desktop-client/release-uploads":                                {"初始化客户端包分片上传", "创建分片上传会话，返回 upload_id、分片大小和分片数量。"},
 	"POST /api/ops/desktop-client/release-uploads/:upload_id/chunks/:chunk_index": {"上传客户端包分片", "Multipart 上传单个客户端安装包或更新包分片。"},
 	"POST /api/ops/desktop-client/release-uploads/:upload_id/complete":            {"完成客户端包分片上传", "校验全部分片，流式写入 OSS，并返回 Object Key、文件大小和 SHA256。"},