Wires the OpenAPI 3.1 generator scaffolding ahead of the iOS-touched
route registrations. `zod-openapi` (samchungy variant, picked in W1
stream-3) reads Zod v4's native `.meta()` so schemas can stay in their
original validation files; `yaml@2` with `sortMapEntries: true` keeps
the emitted spec stable across re-runs.
`pnpm openapi:generate` overwrites `docs/api/openapi.yaml` from the
registry; `pnpm openapi:check` exits non-zero on drift. The legacy
hand-maintained spec is preserved at `docs/api/openapi-v1422-legacy.yaml`
so the iOS contract reference doesn't disappear during the
incremental migration.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
