fix(transfer): treat auto type as unspecified in manual transfer

app/api/endpoints/transfer.py

@@ -138,8 +138,15 @@ def manual_transfer(transer_item: ManualTransferItem,
     else:
         return schemas.Response(success=False, message=f"缺少参数")
 
-    # 类型
-    mtype = MediaType(transer_item.type_name) if transer_item.type_name else None
+    # 类型（“自动/auto”按未指定处理）
+    mtype = None
+    if transer_item.type_name:
+        type_name = str(transer_item.type_name).strip().lower()
+        if type_name not in ["自动", "auto", "none", ""]:
+            try:
+                mtype = MediaType(transer_item.type_name)
+            except Exception:
+                return schemas.Response(success=False, message=f"不支持的媒体类型：{transer_item.type_name}")
     # 自定义格式
     epformat = None
     if transer_item.episode_offset or transer_item.episode_part \