Core Principles

• One direction for data: Components → Hooks (React Query) → lib/actions (services) → HTTP adapters.
• Server data is not in stores: Stores keep IDs/filters/UI flags only.
• Shareable state belongs in the URL: filters/sort/page are linkable & restorable.
• Hooks are pure behavior: UX (toasts/navigation) stays in components.
• One list shape across the app: { items, page?, totalPages?, nextCursor?, hasNextPage }.
• Test seams, not guts: adapters few; services most; hooks behavior; a handful of E2E flows.

Short, timeless, and enforced by our PR checklist and ESLint rules.