CI: install LeRobot with CPU-only PyTorch so the export job fits on the runner

Export runs as LeRobot datasets

Add a first-pass video review with NVIDIA Cosmos Reason

Add robustness sweeps with MuJoCo Warp

Add a ROS 2 sandbox that builds, lints, tests and launches packages

Use GLM-5.3 via OpenRouter and run simulations on Modal (RunPod optional)

Fix scene validation breaking when a GL backend is configured

Harden simulation runs: official Foxglove embed, WebM video, CI image build