POST /users/{id}/promote and /demote set a user's role (admin/user), admin-only
(403 otherwise). Mirrors the verify endpoints: SetRole use case + repo method,
validated role. Unit, admin-flow, and integration tests included.
POST /users/{id}/promote and /demote set a user's role (admin/user), admin-only
(403 otherwise). Mirrors the verify endpoints: SetRole use case + repo method,
validated role. Unit, admin-flow, and integration tests included.