Wave 3: the plan protocol collapses to one re-callable mermaid plan_init
(seven mutation tools deleted by design; statuses derive from quiz checks;
live quiz-nodeId validation with mid-turn retry). The steer-starvation arc:
steers deliver coalesced with the learner's answer (claimSteers), persist
dedupes same-id continuation copies, jobs settle-sync defers while a turn
is busy. Research steers gain the collapsed full-brief affordance. Model
reasoning effort set to minimal across roles.