Compare median post-error intra-command IATs against baseline (commands not immediately following an errored command): * ratio ≥ STRESS_EUSTRESS_RATIO_MIN (1.20) → eustress_positive * ratio ≤ 1/STRESS_DISTRESS_RATIO_MIN → distress_negative * otherwise → none Confidence hard-capped at 0.5; 0.30 below STRESS_MIN_ERRORED_WITH_IATS (2).