# Log
- 2026-10-30 P0 contract written.
- 2026-10-30 P1 audit done: clean, balanced data; no exclusions.
- 2026-10-30 P2 baseline: tau_hat + iid SE. Decision: main SE = CR1 cluster by school, t(G−1=39) inference.
- 2026-10-30 P3 analysis.py written and run.
- 2026-10-30 P4 verification checks; gate run.
- 2026-10-30 P4 passed (gate receipt 20261030T043528); P5 report/claims written; final gate run.