Live grid carbon intensity, deterministic. Answers "how clean is the grid right now", "gCO2 per kWh in Germany", "cleanest hour to run a job today". Current intensity + forward curve (to 48h) + cleanest and dirtiest slots, from NESO (GB national + 14 DNO regions) and energy-charts/Fraunhofer ISE (DE FR NL BE AT ES IT NO). No LLM, no key. Pair with /api/energy/compute-window for full job scheduling