The direct-URL (sourceUrl) path returned { success: true } even when no audio
file was produced (e.g. YouTube 403 / bot check), so the job was marked
"done/Fertig!" and web + Android both said the track was added. It now returns
{ failed: true } → the server sets status 'error' with a clear message, which
both frontends already render as a failure. Search-cascade path was already
correct.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>