Fix Docker Exit Code 137: Diagnose and Prevent OOMKilled Containers

Docker exit code 137 (128+9) indicates a SIGKILL, often from the kernel OOM killer when a container exceeds its memory limit or the host runs out of RAM. Use `docker inspect` to confirm OOMKilled status and `dmesg` to check kernel logs. Common causes include missing or too-low memory limits, memory leaks, or runtimes ignoring cgroup constraints.