Mount Docker socket and add service port range

[silv-io]

The container was missing critical configuration that the old CLI provides. This adds:

• Docker socket mount — mounts the host Docker socket into the container so LocalStack can manage sibling containers (Lambda, ECS, etc.). Socket path is derived from the Docker client connection, supporting DOCKER_HOST and fallback probing for Colima/OrbStack.
• Service port range — maps ports 4510-4559 for external service ports (Lambda, ECS container port binding).
• Container env vars — sets GATEWAY_LISTEN, MAIN_CONTAINER_NAME, and DOCKER_HOST inside the container.
• Runtime interface — adds BindMount, PortMapping, ExtraPorts to ContainerConfig and SocketPath() to the Runtime interface.

Also addresses DRG-573 by probing ~/.colima/default/docker.sock when DOCKER_HOST is unset and the default socket doesn't exist.

Todo

• Volume mount for persistence (will work differently in the new CLI)

Related

• FLC-501
• DRG-573