Fixed Docker Detection on macOS

[blakejosephjames1-ctrl]

This resolves #164

By detecting macOS by falling back on docker.from_env() if no macOS socket is found.

On macOS, Docker Desktop exposes its socket at non-standard paths (~/.docker/run/docker.sock and the Python Docker client does not detect these by default.

Changes

• Added macOS-specific Docker socket detection in DockerRuntime.init.
• Fallback to docker.from_env() if no macOS socket is found.
• Error messages provide OS-appropriate hints.

Note:

This fix has not been tested locally It may require review and verification on a macOS Docker environment.