What problem does it solve? Teams know their codebase is hard to change but lack a disciplined way to find which structural change is actually worth making. This Skill reads the repo's churn history, module shapes, and tests, then ranks refactoring candidates against two evidence gates and crowns exactly one, producing a reviewable proposal instead of a generic smell list. ## Core Features & Use Cases - Churn-ranked survey: Uses git history to rank files by change frequency and detect co-changing files, then clusters hot files into 3-5 areas for analysis. - Four closed friction patterns: Hunts only for shallow interfaces, adapter prevalence, untested coupling, and poor locality, each verified against a deletion test and a test-surface gate. - Single crowned proposal: Ranks surviving candidates by strength, leverage, and blast radius, crowns one, and writes a durable Markdown proposal with a Mermaid before/after diagram to docs/refactor/. - Use Case: Run it on a payments module that feels painful to modify; it reads the tree, finds that adapter clusters on one boundary fail the deletion test while a shallow service layer passes both gates, and writes a proposal naming the exact files and callers affected. ## Quick Start Ask the agent to survey this repository with refactorkit and propose the one structural refactoring most worth making.