openspec-driftlisted

## Purpose Every other verification level asks "did we do what the spec said?" This one asks the harder, opposite question too: "is there anything here the spec never said?" Drift is bidirectional, and the direction nobody checks — code with no requirement behind it — is where scope creep and undocumented behavior accumulate. ## Invocation conditions - Composed by `openspec-audit` in `strict`, `release`, and `forensic` modes. - Consumed by `openspec-verify` as its Level 6 — that skill reads this one's summary verdict and does **not** reimplement the checks inline. - Directly, `/openspec-drift`, when a change feels like it has grown beyond its proposal. ## Required inputs - A change-id, or "all unshipped changes" (default). - A phase range to diff against (defaults to the phase's first commit through `HEAD`). ## Files read - `openspec/changes/<change_id>/**` and `openspec/specs/**` (including `changes/archive/` in forensic mode) - `.planning/openspec/TRACEABILITY.md`, `EVIDENCE.json`, `id-registry.json` - `.planning/phases/<NN>-<slug>/**` — `OPENSPEC-LINK.md`, `PLAN.md`, `SUMMARY.md`, `VERIFICATION.md` - `git log --oneline <phase-start-ref>..HEAD`, `git diff --stat`, `git diff` per commit ## Files this skill may write - `.planning/openspec/DRIFT.md` (overwritten each run — a snapshot, like `AUDIT-SUMMARY.md`) - Never writes to `openspec/`. Never writes to `EVIDENCE.json` (that is `openspec-verify`/`openspec-traceability` territory). ## Algorithm — the nine drift clas