ConvertX Vulnerable to Arbitrary File Deletion via Path Traversal in `POST /delete`

ConvertXis a self-hosted online file converter. In versions prior to 0.17.0, the `POST /delete` endpoint uses a user-controlled `filename` value to construct a filesystem path and deletes it via `unlink` without sufficient validation. By supplying path traversal sequences (e.g., `../`), an attacker can delete arbitrary files outside the intended uploads directory, limited only by the permissions of the server process. Version 0.17.0 fixes the issue.