Interactive first-run wizard for API-key-authenticated CLIs. Masked prompt, live validation against your API, then save via your callback. Generic over validator + save — no assumption about TOML/JSON/keychain storage. Throws typed errors, never calls `process.exit`. Extracted from v0-cli.
pnpm dlx shadcn@latest add "https://cligentic.railly.dev/r/api-key-wizard.json"