Name or ID of the existing VM that Jenkins will clone for each new agent. Use whatever identifier format the Parallels DevOps Service expects—typically the VM name (e.g., macos-sonoma-base) or VM ID (e.g., dcc2016e-5563-4bf4-8312-1492ec8f1663). This base VM should already be registered in prl-devops-service and prepared for agent launch.