fix(confidence-engine): resolve synthesis model configuration

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

@@ -384,6 +384,50 @@ describe("synthesizeCurrentUnderstanding — full seam", () => {
     ).rejects.toThrow(/OLLAMA_BASE_URL/);
   });
 
+
+  // ── Configured model resolution ──────────────────────────
+
+  it("default synthesis path resolves configured modelName — provider receives non-null", async () => {
+    const fake = makeFakeProvider();
+
+    // Stub the configured model so test does not depend on dev-machine .env.local
+    const savedModel = process.env.OLLAMA_MODEL;
+    process.env.OLLAMA_MODEL = "configured-model-v0.50";
+
+    try {
+      const result = await synthesizeCurrentUnderstanding(
+        { situationGraph: canonicalGraph, findings: [] },
+        { provider: fake }
+      );
+
+      expect(result.currentUnderstanding).toBe("Synthesized output");
+
+      // KEY ASSERTION: configured model must flow to provider
+      const receivedModel = fake.generateReconstruction.mock.calls[0][1];
+      expect(receivedModel).toBeDefined();
+      expect(receivedModel).not.toBeNull();
+      expect(typeof receivedModel).toBe("string");
+      expect(receivedModel.length).toBeGreaterThan(0);
+    } finally {
+      // Restore original env value (may be undefined)
+      if (savedModel == null) {
+        delete process.env.OLLAMA_MODEL;
+      } else {
+        process.env.OLLAMA_MODEL = savedModel;
+      }
+    }
+  });
+
+  it("explicit modelName dependency overrides default — provider receives injected model", async () => {
+    const fake = makeFakeProvider();
+    await synthesizeCurrentUnderstanding(
+      { situationGraph: canonicalGraph, findings: [] },
+      { provider: fake, modelName: "test-model-v0.50" }
+    );
+
+    expect(fake.generateReconstruction.mock.calls[0][1]).toBe("test-model-v0.50");
+  });
+
   // ── Provider sees full graph, not just centralStatement ───
 
   it("provider receives full canonical graph content (nodes + edges + centralStatement)", async () => {