1- 2026-10-30 P0 passed: contract written.2- 2026-10-30 P1 passed: 12 negative training_hours rows excluded (sensitivity kept).3- 2026-10-30 P2/P3 passed: naive -0.132; adjusted 0.254 (HC1). Sign flip from skill confounding.4- 2026-10-30 P4 passed: clean rerun identical; all checks pass.5- 2026-10-30 P5 passed: report and claims written.6