The queue name is now a constant (NatsPublisherJob::QUEUE = 'nats') instead of
reading events.nats.queue / NATS_QUEUE, so an env override can no longer put the
publish jobs back behind unrelated work. NatsCommandHandlerJob explicitly stays
on 'default' (its previous behaviour) so long-running commands never block
publishing. Needs a queue worker for 'nats' (main project supervisord).

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>