question tools: phase-visible names, hardened teach schemas, context-slim seams

The tools_fails_2 diagnosis (glm-5.3 dropping trailing required fields):
- probe-phase quiz/explain renamed to probe/recall — a shared name carried
  the probe call shape into teaching (the first teach quiz dropped nodeId);
  display seams accept the old names forever
- teach quiz+explain schemas lead with the required pair (type, nodeId);
  explain gains the predict/check type and joins the reveal law (checks
  collapse, predictions arrive open; no-type records render check-style)
- plan_init/probe_done results go context-slim (owner, context diet):
  content = validated nodeIds + binding-id reminder / fixed ack; details
  keeps the tree for the popup and {ok:true} — serializer-verified that
  details never reaches the model; failure echoes dropped
- the cards carry the tool's own name (Probe/Recall) and the quiz type
  reads on the label (Prediction/Check) in composer and transcript

tests/chat-flow.test.ts

@@ -1107,6 +1107,7 @@ it("explain tool call persists as a pending part; the free-text answer reveals t
 		question: "Explain why Mercury is hard to observe.",
 		correctAnswer: "Its small angular separation from the Sun — it never strays far from the Sun in our sky.",
 		nodeId: "planet-order",
+		type: "check", // the teach explain's role field (owner, 2026-10-09)
 	};
 	const { engine, calls } = scriptedTeacher((cs) => [
 		(context) => {