Return the authenticated principal's server-computed capability snapshot — a pure projection of the shared authorization resolver. This is a coarse, menu-level UI signal Flow uses to render/disable affordances; it is not the enforcement boundary. This snapshot alone never authorizes a booking/trip write — its values must not be treated as a security guarantee. Fine-grained, per-resource decisions are a Phase 2 concern (AuthZEN POST /access/v1/evaluation), never this field.