Add an optional paid AI subscription after the free launcher is released. Define the included requests or token budget, model/provider costs, reset period, remaining-usage display, limits and upgrade behavior. Use Stacks native authentication, commerce and model APIs and StoreKit billing where required by Apple. Keep local launcher features available without a subscription. Obtain explicit consent before sending command, snippet or clipboard content to an AI provider. Resolve Apple paid agreement, tax and banking prerequisites before enabling purchases. Research App Store rules and model pricing at implementation time. Acceptance: reviewed unit economics, clear usage accounting and privacy flow, verified purchase/restore/cancel behavior, and tests that prevent charging or consuming usage twice on retries.