Local live deployment keeps running after SIGTERM and can be deployed twice #681

Expected Behavior

When the lean process running a local (non-detached) lean live deploy is terminated, the LEAN container stops too, as it does on Ctrl+C. Starting a second local live deployment of a project whose deployment is still running is refused, or at least warned about.

Actual Behavior

• DockerManager.run_image registers a handler for SIGINT only (lean/components/docker/docker_manager.py:242), and the container always runs detached. On SIGTERM or SIGHUP (closed SSH session, systemctl stop, timeout, a cancelled CI job or k8s pod) the CLI exits with 143 and the container keeps trading. Reproduced with Docker 29 on Linux.
• lean live deploy does not look for a running container of the same project. Containers get a random lean_cli_<uuid> name, so a restart (for example a systemd unit with Restart=always, or simply running the command again after the above) starts a second algorithm on the same brokerage account.

Potential Solution

1. Route SIGTERM and SIGHUP (where available) through the existing signal_handler, so they stop the container like Ctrl+C.
2. Label LEAN containers with the project path or id, the environment and the brokerage (labels in run_options).
3. In live deploy, look up running containers with the same project label and refuse with a clear message, offering lean live stop <project> or a --force flag.

Step 1 is small and I can open it as a PR first. Steps 2 and 3 change the deploy flow, so I'd like to confirm the approach before writing them.

Reproducing the Problem

lean live deploy MyProject --brokerage "Paper Trading" ... &
kill -TERM $!
docker ps --filter name=lean_cli_   # the container is still running
lean live deploy MyProject --brokerage "Paper Trading" ...   # a second container starts

System Information

lean-cli master at b4d724c, Python 3.12, Linux, Docker 29.

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