#5494 Bug: Orphan task output directories are not cleaned up after server restart

I have consulted the online AI assistant but was unable to obtain a solution to the issue.

In mineru-api (mineru/cli/fast_api.py), AsyncTaskManager manages asynchronous parsing tasks and cleans up task output directories during runtime via cleanup_expired_tasks().
However, cleanup_expired_tasks() only iterates over tasks tracked in the in-memory self.tasks dictionary.
When the service restarts, crashes, or is redeployed, self.tasks in memory is reset to empty.
Any output directories created under output_root prior to the restart become orphaned: they are never tracked in memory again and therefore are never deleted by cleanup_expired_tasks().
Over time, these orphaned directories accumulate permanently on the file system, causing serious disk space leaks in production environments.
Expected behavior: The service should scan output_root on startup and during the periodic background cleanup loop to remove expired orphan directories whose disk modification time exceeds task_retention_seconds.

Start the FastAPI service via mineru-api.
Submit one or more asynchronous parsing tasks so that task output directories are created under the output root directory.
Terminate or restart the mineru-api process.
Restart the service and wait longer than task_retention_seconds.
Check the output root directory on disk; the previous task output folders still persist indefinitely.

Linux

Linux Mint 22.3

3.12

>=2.5

vlm

cuda