bug : Path traversal in /files and /open_folder because task_id is not validated

[yomo40]

Both files and /open_folder call get_work_dir(task_id); however, get_work_dir simply performs os.path.join("project", "work_dir", task_id) followed by os.path.exists(), unlike /messages which first checks ensure_safe_task_id. This means that when passing values ​​like ../../.., the path might be resolved to a directory outside the task directory.

Caution

/files can be used to enumerate a list of files in any existing directory; /open_folder might even attempt to open the path on the server. It is a potential entry point for path traversal.