Log
- 2026-10-30 P0 passed: contract written.
- 2026-10-30 P1 passed: audit done; decision to exclude 12 negative training_hours rows, with sensitivity on all rows.
- 2026-10-30 P2/P3 passed: baseline and adjusted OLS (HC1) in analysis.py.
- 2026-10-30 P4 passed: clean rerun identical; checks.md.
- 2026-10-30 P5 passed: report and claims written. Task complete.