refactorlisted

# refactor — sharpen it in place Take what exists and **sharpen it, round after round**, until another pass stops being worth it. Sibling of **rewrite**. Same tournament, opposite move: | | rewrite | refactor | | --- | --- | --- | | Starting point | blank file, spec only | the champion's actual code | | Round output | a whole new version | a **reviewable diff** | | Question it answers | "is a different design better?" | "how good can *this* design get?" | | Ends when | a fresh attempt stops winning | a diff stops being worth its cost | If mid-run the honest answer becomes *"this needs to be thrown away, not patched"*, **stop and say so**, then recommend `rewrite`. Grinding polish onto the wrong design is the failure mode this skill has to avoid. --- ## 0. Pick the target If the user passed an argument, that is the target (`/refactor src/parser.ts`). If not, ask **one question**: what should be improved. Then write the **behaviour contract** — 3-8 bullets of what must stay true no matter what changes. This is not a wish list, it is a fence. Anything not in it is fair game to change; anything in it is a regression if broken. If the run is *meant* to change behaviour (fixing a known bug, tightening a limit), write that as an explicit bullet before round 1. Silent behaviour changes discovered in round 4 poison every earlier comparison. ## 1. Setup (round 0) 1. **Champion = the current code.** Read it properly, all of it. 2. **Freeze the rubric** (§3) and **score the ch