/** * DisplayObject contract * * Deterministic, reusable, UI-only formatting/mapping logic. * * Based on DISPLAY_OBJECTS.md: * - Class-based * - Immutable * - Deterministic * - Side-effect free * - No Intl.* or toLocale* * - No business rules */ export interface DisplayObject { /** * Format or map the display object * * @returns Primitive values only (strings, numbers, booleans) */ format(): unknown; /** * Optional: Get multiple display variants * * Allows a single DisplayObject to expose multiple presentation formats */ variants?(): Record; }