Scope Fence — one step, one scope, nothing sneaks in — refactor-chain · do-the-work

Bundle: refactor-chain (self-diagnosing, self-healing fix-it pipeline). Phase: do-the-work — a standing contract over every executing step · Prerequisite: an active chain with a current step (state.json exists, state.steps[cursor] set) · Next: the step's own verify, then advance. Adaptivity / conditional: repo-agnostic; active whenever a chain step is executing. The drift signal comes free from the guard hook; this skill supplies the discipline.

Purpose

Every chain step declares its territory: state.steps[cursor].scope, a list of path prefixes. Inside the fence, work proceeds; outside it, nothing gets edited — no matter how broken, ugly, or tempting the adjacent code is. "While I'm here" is how a rename becomes a rewrite, how diffs become unreviewable, and how a green baseline stops meaning anything. Adjacent problems are treasure, not chores: they get flagged and parked (a note in state plus a line in the write-up) so they become deliberate future work instead of silent scope creep.