复查修复(三): 调度与扫描

- scan: .tmp/.part 过滤 + list_files 分批遍历(消除 10 万条截断误判)
- Scheduler: 持锁只做标记, 锁外异步执行任务(长任务不再冻结调度)
- cron 范围/步进边界校验;FTP 下载后大小校验防静默截断

core/mirror_sync.py

@@ -1307,6 +1307,12 @@ class MirrorSyncManager:
                     ftp.retrbinary(f'RETR {remote_filename}', f.write, rest=start_pos)
                 else:
                     ftp.retrbinary(f'RETR {remote_filename}', f.write)
+
+            # 校验下载大小与远端一致，防止静默截断
+            actual_size = os.path.getsize(local_path)
+            expected = file_info.get('size')
+            if expected is not None and expected > 0 and actual_size != expected:
+                raise Exception(f"文件大小不匹配: {actual_size} != {expected}")
             
             return True
         except Exception as e: