fix(confidence-engine): unwrap synthesis provider response

lib/graph/current-understanding-synthesis.js

@@ -279,9 +279,9 @@ export async function synthesizeCurrentUnderstanding(
     modelName = process.env.OLLAMA_MODEL ?? null;
   }
 
-  let rawResponse;
+  let providerResult;
   try {
-    rawResponse = await provider.generateReconstruction(
+    providerResult = await provider.generateReconstruction(
       prompt,
       modelName,
       synthesisOutputSchema,
@@ -293,7 +293,7 @@ export async function synthesizeCurrentUnderstanding(
   }
 
   // 5. Validate response
-  const validated = validateSynthesisResponse(rawResponse);
+  const validated = validateSynthesisResponse(providerResult.response);
   if (!validated.valid) {
     const err = new Error(`Synthesis validation failed: ${validated.error}`);
     err.statusCode = 502;

tests/graph/current-understanding-synthesis.test.js

@@ -56,9 +56,10 @@ const agreedFinding = () => ({
 /** Fake provider factory for tests */
 const makeFakeProvider = (defaultResponse) => ({
   generateReconstruction: vi.fn(async () => {
-    return typeof defaultResponse === "function"
+    const response = typeof defaultResponse === "function"
-      ? defaultResponse()
+      ? await defaultResponse()
       : JSON.stringify({ currentUnderstanding: "Synthesized output" });
+    return { response, providerApiPath: "/test-provider" };
   }),
 });
 
@@ -383,6 +384,14 @@ describe("synthesizeCurrentUnderstanding — full seam", () => {
     });
   });
 
+  it("unwraps the provider response before validating the synthesis narrative", async () => {
+    const fake = makeFakeProvider(() => ({ currentUnderstanding: "Wrapped narrative" }));
+    await expect(synthesizeCurrentUnderstanding(
+      { situationGraph: fullScenario, findings: [] },
+      { provider: fake },
+    )).resolves.toEqual({ currentUnderstanding: "Wrapped narrative" });
+  });
+
   it("supported node content flows to provider via synthesis prompt", async () => {
     const fake = makeFakeProvider();
     await synthesizeCurrentUnderstanding(