/**
 * The letter workflow's acting role: drafter or approver for the two-person
 * compose/review flow, admin for org-template management (WP-23, Brief v2).
 * A pure domain type (no framework, no reading mechanism) — the `?role=` reader and
 * the X-Role header live in shared/infrastructure/role.ts. Consumers (brief.store,
 * letter-composer) depend on this type, not on how the role is obtained.
 */
export type Role = 'drafter' | 'approver' | 'admin';