Experimental 7-day current-regime risk score

Experimental 7-day current-regime risk score. summary.max_risk comes from the model named in model_version, and forecast_trajectory_note explains the fields; the per-day forecast[] trajectory is the legacy v1 XGBoost shape. Onset timing is unproven: it is not a prediction of when a shutdown starts, and no validated skill or accuracy figure is published. Limits: /v1/forecast/onset-skill.