- 2026-10-30 P0 passed: contract written. Decided not to read gate_spec.json (grading file, not an input).
- 2026-10-30 P1 passed: hashes verified, data recomputed from monthly file, one exclusion (1995Q1 NaN).
- 2026-10-30 P2/P3 passed: snaive baseline + seasonal AR (dummies, AIC p<=4, iterated). HAC Bartlett L=4 chosen a priori (>= h-1=3; Bartlett guarantees positive LRV).
- 2026-10-30 P4 passed: deterministic rerun, consistency and leakage checks.
- 2026-10-30 P5 passed: report, claims written. Task complete.