mod/decision-diff compares one report's action under two rule sets;
mod/policy-impact batches a set and returns only the reports whose decision flips;
mod/impact-count / mod/impact-report summarize. Lets a mod team measure a policy
change's blast radius before shipping (e.g. removing spam-hide flips r1 hide→keep).
Pure SX over decide-report. +13 tests.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
