Feature Rollout with Dependency Cycle Detection

Requirements For each (user, feature) pair, produce a ResultDecision containing enable: bool and reason: string. Evaluate the rules in the order below and stop as soon as a failing rule is found: Country gate — When the user's country is absent from the feature's allow-set, return enable=False with the country-rejection reason string. Use the system-provided allow-set helper instead of duplicating its logic. OS version gate — Android and iOS have separate minimum-version…