Fix a lifecycle error found during the final HA review: after the startup event had fired, reloading the integration tried to remove its listener a second time. Listener cleanup now runs exactly once, and queued events after unloading are ignored. Normal WebSocket task cancellation is logged at debug level.
Validation: 107 automated tests passed, Python compilation and release archive checks passed. Installed on the demo HA and checked repeated integration reloads with 96 stable entities and healthy UDP reception. Existing project backups are retained.
Restart Home Assistant after updating through HACS.