e1fd8ef1b4
Give every backend a `gateway_transport.py` holding just its `GatewayTransport` impl, named consistently with the backend: `DockerGatewayTransport`, `MacosGatewayTransport` (was `AppleGatewayTransport`), and `FirecrackerGatewayTransport` (was `SshGatewayTransport`). - docker: split `DockerGatewayTransport` out of `gateway_provision.py`, which keeps only the backend-neutral provisioning logic (provision_git_gate / deprovision_git_gate) the other backends share. - macOS: `gateway_provision.py` held only the transport, so it's replaced by `gateway_transport.py`. - firecracker: move the transport out of `gateway.py`. Behaviour-preserving; importers + tests updated. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>