补充运行说明并实现基础导出能力

backend/services/minio_client.py

@@ -1,3 +1,6 @@
+import io
+from datetime import timedelta
+
 from minio import Minio
 from config import settings
 
@@ -34,4 +37,34 @@ def get_file_url(bucket: str, object_name: str) -> str:
 
 def get_presigned_url(bucket: str, object_name: str, expires: int = 3600) -> str:
     """获取预签名下载 URL（带过期时间）"""
-    return minio_client.presigned_get_object(bucket, object_name, expires=expires)
+    return minio_client.presigned_get_object(bucket, object_name, expires=timedelta(seconds=expires))
+
+
+def split_bucket_path(file_path: str) -> tuple[str, str]:
+    if "/" not in file_path:
+        raise ValueError("非法的 MinIO 文件路径")
+    return file_path.split("/", 1)
+
+
+def download_object_bytes(bucket: str, object_name: str) -> bytes:
+    response = minio_client.get_object(bucket, object_name)
+    try:
+        return response.read()
+    finally:
+        response.close()
+        response.release_conn()
+
+
+def upload_bytes(
+    bucket: str,
+    object_name: str,
+    content: bytes,
+    content_type: str = "application/octet-stream",
+):
+    minio_client.put_object(
+        bucket,
+        object_name,
+        io.BytesIO(content),
+        len(content),
+        content_type=content_type,
+    )