Does AI Help? Final October 2026 release

Final October baseline, version 2026.10.14, evidence cutoff 13 October 2026. The final editorial self-review is recorded in manuscript/october-final-review.md. Corrections distinguish randomized and quasi-experimental evidence, include mixed customer-support subgroup outcomes and learning evidence, and clarify the scope of the mathematical translation critique. Tags v2026.10.14 and october-2026-final identify the same publication commit. November preparation proceeds separately on codex/november-2026-preparation.