ui: ProblemCard/ConcludeCard redesigned — the solution is the hero

Owner round (2026-10-05), Slice C:

- ProblemCard: ALWAYS OPEN — the answered card's container + eyebrow
  discipline ('Problem' label, lh-prose statement), no chevron, no
  collapsed bar. The dock mirrors it in Slice D.
- ConcludeCard: the reveal is the modelSolution committed at POSE time,
  shown verbatim as the hero — never re-authored (the slim schema's
  law). The verdict rides below in the quiz-explanation register
  (small, muted 'Verdict:' row). Nothing collapsible. Legacy inputs
  with their own solutionReveal fall back to it.
- The reveal join: modelSolutionForConclude (native-messages.ts) — the
  newest cleanly-posed problem before the conclude call; refused poses
  reveal nothing. projectView enriches tool-conclude parts with
  part.reveal at projection; ArtifactPartProps carries the field
  (contracts/chat.ts).

Pinned: always-open problem card; hero-first conclude layout with the
verdict after it; legacy fallback; the join (clean pose, refused pose,
multi-problem records) and the view enrichment.

tests/practice-record.test.ts

@@ -27,6 +27,8 @@ import {
 } from "../src/core/native-messages.ts";
 import { CONCLUDE_ACK_TEXT } from "../src/core/contracts/chat.ts";
 import { dismissAppends, inputAppends, parseChatInput, parseDismissInput } from "../src/core/input-events.ts";
+import { modelSolutionForConclude } from "../src/core/native-messages.ts";
+import { projectView } from "../src/core/index.ts";
 
 // ── builders (native-shaped test fixtures) ───────────────────────────────────
 
@@ -50,7 +52,7 @@ function problemPose(callId = "call_p1", statement = "Show that…"): LhMessage[
 		id: `msg_a_${callId}`,
 		role: "assistant",
 		content: [
-			{ type: "toolCall", id: callId, name: PRACTICE_PROBLEM_TOOL, arguments: { statement, mode: "recall" } },
+			{ type: "toolCall", id: callId, name: PRACTICE_PROBLEM_TOOL, arguments: { statement, mode: "recall", modelSolution: statement } },
 		],
 		timestamp: 1,
 		...STAMPS,
@@ -110,7 +112,7 @@ describe("activeProblemOf (the conclude-before-next-problem gate's fold)", () =>
 		const messages = problemPose();
 		const active = activeProblemOf(messages);
 		assert.equal(active?.toolCallId, "call_p1");
-		assert.deepEqual(active?.input, { statement: "Show that…", mode: "recall" });
+		assert.deepEqual(active?.input, { statement: "Show that…", mode: "recall", modelSolution: "Show that…" });
 	});
 
 	it("thinking submissions keep it active (nudges never conclude)", () => {
@@ -345,3 +347,39 @@ describe("needsContinuation (a persisted pose ack owes nothing)", () => {
 		assert.equal(needsContinuation(messages), true);
 	});
 });
+
+
+// ── the reveal join (owner round, 2026-10-05) ───────────────────────────────
+
+describe("modelSolutionForConclude (the conclusion's hero is the pose's commitment)", () => {
+	it("returns the cleanly-posed problem's modelSolution before the conclude", () => {
+		const messages = [...problemPose(), ...concludeCall("solved")];
+		assert.equal(modelSolutionForConclude(messages, "call_conclude_solved"), "Show that…");
+	});
+
+	it("skips refused poses — a rejected pose revealed nothing", () => {
+		const rejected = problemPose("call_bad", "A different student…");
+		(rejected[1]! as unknown as { isError: boolean }).isError = true;
+		const messages = [...rejected, ...concludeCall("solved")];
+		assert.equal(modelSolutionForConclude(messages, "call_conclude_solved"), undefined);
+	});
+
+	it("the newest pose before ITS conclude wins (multi-problem records)", () => {
+		const messages = [
+			...problemPose("call_p1", "first"),
+			...concludeCall("solved"),
+			...problemPose("call_p2", "second"),
+			...concludeCall("movedOn"),
+		];
+		assert.equal(modelSolutionForConclude(messages, "call_conclude_movedOn"), "second");
+		assert.equal(modelSolutionForConclude(messages, "call_conclude_solved"), "first");
+	});
+
+	it("projectView enriches the conclude part with the reveal", () => {
+		const messages = [...problemPose(), ...concludeCall("solved")];
+		const view = projectView(messages);
+		const conclude = view.flatMap((m) => m.parts).find((p) => p.type === "tool-conclude");
+		assert.ok(conclude, "the conclude part projects");
+		assert.equal(conclude!.reveal, "Show that…", "the view-seam join carries the committed solution");
+	});
+});

tests/render-practice-surface.test.tsx

@@ -76,7 +76,7 @@ describe("PracticeDock", () => {
 // ── the transcript cards ─────────────────────────────────────────────────────
 
 describe("the practice transcript cards", () => {
-	it("ProblemCard: the statement renders — the commitment NEVER does", () => {
+	it("ProblemCard: ALWAYS OPEN, the 'Problem' eyebrow + the statement — the commitment NEVER renders", () => {
 		const html = renderToStaticMarkup(
 			<ProblemCard
 				part={part({
@@ -84,33 +84,48 @@ describe("the practice transcript cards", () => {
 						statement: "Prove the parity claim.",
 						mode: "recall",
 						modelSolution: "Pair them.",
-						decisionPoints: ["pairing"],
-						expectedWrongMoves: [{ move: "induction", resolution: "pairing is direct" }],
-						strategy: "near-twin",
-						rationale: "weakest target",
 					},
 				})}
 			/>,
 		);
 		assert.match(html, /data-testid="problem-card"/);
+		assert.match(html, /Problem/);
 		assert.match(html, /Prove the parity claim\./);
-		for (const hidden of ["Pair them.", "induction", "near-twin", "weakest target", "pairing"]) {
-			assert.doesNotMatch(html, new RegExp(hidden.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")), `commitment leaked: ${hidden}`);
-		}
+		assert.doesNotMatch(html, /Pair them\./, "the commitment stays hidden");
+		// No chevron, no collapsed bar (owner round, 2026-10-05).
+		assert.doesNotMatch(html, /lucide-chevron|<button/, "nothing collapsible");
 	});
 
-	it("ConcludeCard: outcome badge + verdict headline; the reveal expands", () => {
+	it("ConcludeCard: the SOLUTION is the hero (the pose's modelSolution via part.reveal); the verdict rides below, low-key", () => {
 		const html = renderToStaticMarkup(
 			<ConcludeCard
 				part={part({
 					type: "tool-conclude",
-					input: { outcome: "solvedWithHints", verdict: "The pairing came after R2.", solutionReveal: "Pair them; each pair is even." },
+					input: { outcome: "solvedWithHints", verdict: "The pairing came after R2." },
+					reveal: "Pair them; each pair is even.",
 				})}
 			/>,
 		);
 		assert.match(html, /data-testid="conclude-card"/);
 		assert.match(html, /Solved with hints/);
+		assert.match(html, /Pair them; each pair is even\./, "the committed solution, verbatim");
+		assert.match(html, /Verdict:/);
 		assert.match(html, /The pairing came after R2\./);
+		// The verdict row renders AFTER the solution (the hero first).
+		assert.ok(html.indexOf("Pair them; each pair is even.") < html.indexOf("The pairing came after R2."));
+		assert.doesNotMatch(html, /<button/, "nothing collapsible");
+	});
+
+	it("ConcludeCard: legacy records fall back to their own solutionReveal", () => {
+		const html = renderToStaticMarkup(
+			<ConcludeCard
+				part={part({
+					type: "tool-conclude",
+					input: { outcome: "solved", verdict: "Clean.", solutionReveal: "Pair them; each pair is even." },
+				})}
+			/>,
+		);
+		assert.match(html, /Pair them; each pair is even\./);
 	});
 
 	it("ConcludeCard: the dismissal synthesis is one muted line — no reveal card", () => {