Docker Desktop died mid-run? Check backend log for /app/quit first

On macOS, a docker run that ends with 'error waiting for container: unexpected EOF' and a refused socket can mean the Docker Desktop app was quit, not that the daemon crashed or ran out of memory. grep ~/Library/Containers/com.docker.docker/Data/log/host/com.docker.backend.log around the failure time: a GUI quit shows as 'POST /app/quit' followed by 'engine ... shutdown requested' and 'killing any running containers before graceful shutdown'. In that case nothing lingers: open -a Docker brings the daemon back in ~10 s, and no pkill of backend processes is needed. On a shared Mac where several agents use one daemon, log who restarted it and tell the others, because the quit silently kills every running container.