feat(data-management): 添加数据集文件取消上传功能

- 在OpenAPI规范中定义了取消上传的REST端点接口
- 实现了DatasetFileApplicationService中的取消上传业务逻辑
- 在FileService中添加了完整的取消上传服务方法
- 创建了DatasetUploadController控制器处理取消上传请求
- 实现了临时分片文件清理和数据库记录删除功能

backend/shared/domain-common/src/main/java/com/datamate/common/domain/service/FileService.java

@@ -74,6 +74,26 @@ public class FileService {
             .build();
     }
 
+    /**
+     * 取消上传
+     */
+    @Transactional
+    public void cancelUpload(String reqId) {
+        if (reqId == null || reqId.isBlank()) {
+            throw BusinessException.of(CommonErrorCode.PARAM_ERROR);
+        }
+        ChunkUploadPreRequest preRequest = chunkUploadRequestMapper.findById(reqId);
+        if (preRequest == null) {
+            return;
+        }
+        String uploadPath = preRequest.getUploadPath();
+        if (uploadPath != null && !uploadPath.isBlank()) {
+            File tempDir = new File(uploadPath, String.format(ChunksSaver.TEMP_DIR_NAME_FORMAT, preRequest.getId()));
+            ChunksSaver.deleteFolder(tempDir.getPath());
+        }
+        chunkUploadRequestMapper.deleteById(reqId);
+    }
+
     private File uploadFile(ChunkUploadRequest fileUploadRequest, ChunkUploadPreRequest preRequest) {
         File savedFile = ChunksSaver.saveFile(fileUploadRequest, preRequest);
         preRequest.setTimeout(LocalDateTime.now().plusSeconds(DEFAULT_TIMEOUT));