Mechanical Refactor — Machine-Checkable Verification

1. Overview

• The correctness of a mechanical change (file split, function move, module extraction, rename) must be machine-checkable, not eyeballed — the proof is something anyone can re-run, whoever made the change and whenever.
• One property: a commit is a pure relocation. One proof: reproduce — regenerate the move from the base commit with faithful primitives, run the formatter, byte-diff against the target.
• Empty diff = the proof. Any residual = a bundled non-move change, surfaced for review.
• A reshape must not ride along: split into optional prepare + certified move + optional postpare (guide-split.md).

2. Commands — what do you want to do?

The skill takes an argument naming one of three commands; invoked without one, pick the row matching your task.