Generate a per-instance Compose override for estate boots so CUDA_VISIBLE_DEVICES and NVIDIA_VISIBLE_DEVICES are set inside each container. This prevents parallel vLLM estate instances from both binding to physical GPUs 0/1 when Docker exposes all reserved devices.\n\nValidated with test-diagnose-estate, test-estate-json, test-profiles-compat, test-launch-compat, and a live 4x3090 estate boot.