A skills library that keeps codebases healthy as coding agents work in them. Repo Hygiene injects a bootstrap at session start and auto-triggers eight sub-skills at hygiene-relevant moments — when starting work in an unfamiliar repo, writing new functions, changing public APIs, drafting commits, and applying retroactive cleanup to existing projects. Complements Superpowers: where Superpowers handles workflow disciplines (brainstorming, TDD, planning), Repo Hygiene handles the lower-level habits that should hold across every change.