reason: Frontend stack and high-level conventions for Next.js, Zustand, SCSS, and TypeScript.


reason: Route-local organization and naming conventions for the billing module.


reason: Component, style isolation, and documentation rules for new billing UI pieces.


reason: Rules for consuming existing Zustand stores and avoiding redundant state.


reason: Type and JSDoc rules for route-local billing interfaces.


reason: Async handling, loading states, defensive data access, and React quality checks.