Judge the delete by the read-back (is the queue gone?) instead of lpadmin's exit
status. Deleting a queue that was removed elsewhere before the sidebar refreshed
made lpadmin fail with 'The printer or class does not exist', and the app showed a
failure alert although the queue was gone. Now the status bar shows 'Deleted <queue>'
and os_log notes it was already deleted. Unit tests for all four outcomes, plus an
opt-in live test (CUPSKIT_LIVE_DELETE=1) on a name that never existed.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
