# Log
- 2026-10-30 P0 passed: contract written.
- 2026-10-30 P1 passed: data clean, no exclusions.
- 2026-10-30 P2 passed: baseline iid OLS SE computed (se_iid).
- 2026-10-30 P3 passed: decision — CR1 cluster-robust SE by school, t(G−1=39) reference; ICC via one-way ANOVA on OLS residuals with G−2 between df. No randomness (random_seed null).
- 2026-10-30 P4 passed: reproducibility and consistency checks all pass.
- 2026-10-30 P5 passed: report and claims written.