Orca continues pulling work from Redis after load balancer removal

Orca service continues to dequeue and process work from Redis even after being removed from a load balancer during shutdown. Unlike distributed environments with Eureka discovery, open-source deployments lack automatic work cessation triggers, causing Orca to keep processing tasks during shutdown attempts.

Before shutting down Orca, explicitly disable the instance using the admin endpoint to stop it from accepting queued work from Redis. Wait a few seconds after disabling before proceeding with shutdown. For systemd-based installations, add an ExecStop entry that calls this disable endpoint automatically.