Produces an API version scheme (date-pinned header or URI), a breaking-vs-additive change policy, and a published deprecation/sunset timeline with translation shims. Use when removing or renaming a field or endpoint, tightening validation, cutting a "v2", binding a partner integration to a version, or planning how long an old version lives. Do NOT use when designing the resource shape, URLs, status codes, or pagination of a new endpoint - use REST API Design instead; this skill owns only the version scheme and deprecation path layered on top of that contract.