/ca-refactor — behavior-preserving restructure

The only permitted entry to refactor work. A refactor that cannot prove parity through unmodified pre-existing tests is a feature change in disguise and routes to /ca-feature. Two required parts: the surface (exact files, functions, classes, or methods — vague surfaces like "the auth module" are rejected) and the motivation (why the restructure is worth doing).

Flow

Routes to the refactor skill — six phases:

1. Surface identification — lock the exact files, symbols, and public signatures.
2. Parity coverage proof — demonstrate pre-existing tests already cover the named surface, with at least one direct test per public method.
3. Red parity tests (conditional) — if the refactor exposes a new test seam, route to tdd (<plugin-root>/routines/tdd/SKILL.md) Phase 1 to write failing tests pinning the seam's contract first.
4. Implementation — apply the restructure mechanically within the surface table; no new behavior, branches, error paths, or side effects.
5. Parity verification — the full pre-existing suite passes with zero edits to any pre-existing test file.
6. Lint / coverage gate — lint, type-check, and coverage clear; surface coverage MUST NOT regress.

Routes to

refactor (<plugin-root>/routines/refactor/SKILL.md) — all six phases.

When NOT to use

• New behavior — a new branch, error path, side effect, public method beyond a Phase 3 seam, or a change to what any input maps to → /ca-feature.
• A change motivated by "the current behavior is wrong" → /ca-fix.
• Questions or discussion → /ca-btw.
• Persisting an already-completed refactor → /ca-commit.

Hard gate

No refactor proceeds without behavioral-parity coverage proof in Phase 2; if the surface is under-covered, the skill halts and routes to tdd Phase 1 to backfill before resuming. A Phase 4 diff that would classify as feat, or a Phase 5 verification that depends on edits to a pre-existing test, terminates the refactor and re-routes to /ca-feature or /ca-fix.