Print error recovery flow (code = 15)

code = 15 means print stage failed (printError may contain printer-specific reason), but business operation can already be committed.

Recommended flow:

1. Receive error response with code = 15.
2. Save documentExtID and full response payload to incident log.
3. Call /check_status for the same document.
4. If docStatus = 1, treat payment/fiscal operation as completed and recover only printing:
   • call /check_copy (requires documentID) after printer issue is resolved.
5. If docStatus = 0 or code = 44, continue polling /check_status.
6. If document is still not found in an unknown-delivery scenario, resend same operation with same documentExtID.