hatch3r-maintainability-verify

# Maintainability Verification Gate ## Quick Start This skill defines what "done" means for any feature shipping code, schema migrations, or API spec changes. Run before declaring a feature complete. The 8 gates below mix automated checks (machine-checkable on every PR) with one release-cadence gate (API breaking-change diff at release-cut). Skipping any gate = the feature is not done. Reviewer approval and passing tests alone do not satisfy this bar — a destructive single-deploy schema change ships data loss; a breaking change without a major bump breaks consumers silently. Inputs the skill expects: - A repository with `src/` source modules (or equivalent). - Migration files under `migrations/`, `db/migrations/`, `prisma/migrations/`, or framework-equivalent. - API spec files (`openapi.yaml`, `openapi.json`, `*.proto`, GraphQL SDL). - An ADR directory (`docs/adr/`, `doc/adr/`) when architectural decisions are touched. - Tooling: `jscpd` (duplication), `eslint` with `complexity` rule (JS/TS) or `radon` (Python) or `lizard` (polyglot), `oasdiff` (REST), `buf breaking` (Protobuf), `graphql-inspector diff` (GraphQL). Outputs the skill produces: an 8-line verdict block written to the PR conversation, plus a JSON artifact at `.audit-workspace/maintainability-verify-<sha>.json` for downstream consumption by `hatch3r-release`. ## Step 0 — Detect Ambiguity (P8 B1) Before any work, scan the invocation for unresolved questions in scope, intent, acceptance criteria, target enviro...