// --- Phase 3 skeletons. `chat` and `mediation` are intentional stubs
// --- pending US1+; see their module headers for open verification
// --- points. `prompts` and `reasoning` are fully implemented as the
// --- foundational boundary.
// --- Phase 4: escalation execution surface (FR-121..FR-218).
// --- The module tree is scaffolded at Phase 2 of the Phase 4
// --- rollout; the consumer/router/dispatcher/tracker layers are
// --- filled in by T011–T016.