test(experiment): ground RTO apparatus in real fixture

lib/mocks/scenarios.js

@@ -1,10 +1,41 @@
 /**
  * Expanded mock scenario library for the Confidence Engine workspace.
  * Each scenario produces a complete investigation journey through turns.
- * 
+ *
  * UI-only development work — no reasoning engine changes.
  */
 
+/* ── RTO.A4 real captured fixture (RTO.A1 superseded) ──────────── */
+
+import fixtureData from "../../tests/fixtures/live-product-launch-update-response.json";
+
+/**
+ * Thin projection of a real captured Engine update response into the
+ * shape already expected by the workspace/mock client.
+ *
+ * The real captured fixture remains the source of truth — no reasoning
+ * content is recreated or synthesized here.
+ */
+function projectRealUpdateFixture(fixture) {
+  return {
+    success: fixture.success,
+    stage: fixture.stage,
+    situationGraph: fixture.updatedSituationGraph,
+    updatedSituationGraph: fixture.updatedSituationGraph,
+    selectedQuestion: fixture.selectedQuestion,
+    newlySurfacedNodeIds: (fixture.proposal?.addedNodes || [])
+      .filter(node => node.kind === "unknown")
+      .map(node => node.id),
+    diagnostics: fixture.diagnostics,
+    noQuestionReason: null,
+    // Mark as experimental so buildScenarioFixture routes through the scenario branch
+    _experimental: { apparatusMode: "rto-real-fixture" },
+    _sourceFixturePath: "../../tests/fixtures/live-product-launch-update-response.json",
+  };
+}
+
+const __rtoRealScenario = projectRealUpdateFixture(fixtureData);
+
 /* ── Node / Edge factories ─────────────────────────────── */
 
 export function mkN(id, label, opts) {
@@ -389,6 +420,11 @@ export var MULTI_THREAD_ITEMS = multiThreadItems;
 /* ── Registry ─────────────────────────────────────── */
 
 var SCENARIOS = {
+  "rto-real-product-launch": {
+    scenario: __rtoRealScenario,
+    label: "[RTO.A4] Real captured product-launch update",
+    centralStatement: __rtoRealScenario?.updatedSituationGraph?.centralStatement || "",
+  },
   "default":       { turns: comparisonTurns,     label: "Comparison (product ratings)", centralStatement: comparisonTurns[0].centralStatement },
   "comparison":    { turns: comparisonTurns,     label: "Comparison (product ratings)", centralStatement: comparisonTurns[0].centralStatement },
   "contradictory": { turns: contradictoryTurns,  label: "Contradictory evidence",       centralStatement: contradictoryTurns[0].centralStatement },
@@ -409,6 +445,11 @@ export function buildScenarioFixture(scenarioName, turnIdx) {
   var s = SCENARIOS[scenarioName];
   if (!s) return null;
 
+  /* RTO.A4 real fixture — returned as-is (already projected) */
+  if (s.scenario && s.scenario._sourceFixturePath) {
+    return s.scenario;
+  }
+
   /* Experimental multi-thread — does not follow the turns model */
   if (s.scenario && s.scenario._experimental) {
     var mt = s.scenario;