Use for Swift AI SDK upstream parity management: refresh or inspect Vercel AI SDK baselines, scan upstream package coverage, classify drift, plan provider/core/docs audits, land parity fixes with tests, and maintain generated local artifacts under .upstream/ plus durable evidence in upstream/.
Instructions for teunlao/vidin, covering agents.md, commands, hard rules, selector invariants (src/core/select.ts) and removed on purpose — don't reintroduce casually.