Drop the grafana service and the homeautomation_grafana_storage volume
declaration from docker-compose.yml (migration and app services unchanged),
and delete the grafana/ provisioning + dashboards directory. Visualization
moves to the M2 React frontend; the named volume's actual data is retired
manually as an ops step, never by automation.
docker compose config -q passes; pytest 95 passed; ruff clean.
tliu93