fix(confidence-engine): log case-start failures

tests/app/api/cases-start-route.test.js

@@ -1,6 +1,8 @@
-import { beforeEach, describe, expect, it, vi } from "vitest";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
 const mockStartCase = vi.fn();
+let warnSpy;
+let errorSpy;
 
 vi.mock("@/lib/graph/orchestrator.js", () => ({
   startCase: (...args) => mockStartCase(...args),
@@ -10,6 +12,13 @@ describe("app/api/cases/start route", () => {
   beforeEach(() => {
     vi.resetModules();
     vi.clearAllMocks();
+    warnSpy = vi.spyOn(console, "warn").mockImplementation(() => {});
+    errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+  });
+
+  afterEach(() => {
+    warnSpy.mockRestore();
+    errorSpy.mockRestore();
   });
 
   it("delegates request body to the orchestrator", async () => {
@@ -78,6 +87,8 @@ describe("app/api/cases/start route", () => {
       success: true,
       reconstruction,
     });
+    expect(warnSpy).not.toHaveBeenCalled();
+    expect(errorSpy).not.toHaveBeenCalled();
   });
 
   it("returns 400 for invalid request input", async () => {
@@ -102,6 +113,12 @@ describe("app/api/cases/start route", () => {
       success: false,
       error: "Invalid start-case request",
     });
+    expect(warnSpy).toHaveBeenCalledTimes(1);
+    expect(warnSpy).toHaveBeenCalledWith(
+      "[api/cases/start] error response",
+      expect.objectContaining({ status: 400, error: "Invalid start-case request" }),
+    );
+    expect(errorSpy).not.toHaveBeenCalled();
   });
 
   it("returns provider/internal failures as 5xx without stack traces", async () => {
@@ -148,6 +165,18 @@ describe("app/api/cases/start route", () => {
         received: "undefined",
       }),
     ]);
+    expect(errorSpy).toHaveBeenCalledTimes(1);
+    expect(errorSpy).toHaveBeenCalledWith(
+      "[api/cases/start] error response",
+      expect.objectContaining({
+        status: 502,
+        error: "Provider unavailable",
+        analysisErrors: ["reconstruction: Required"],
+        validationIssues: expect.any(Array),
+        rawResponse,
+      }),
+    );
+    expect(warnSpy).not.toHaveBeenCalled();
   });
 
   it("returns structured 500 on malformed JSON", async () => {
@@ -163,5 +192,13 @@ describe("app/api/cases/start route", () => {
       success: false,
       error: "Internal server error",
     });
+    expect(errorSpy).toHaveBeenCalledWith(
+      "[api/cases/start] unhandled exception",
+      expect.objectContaining({
+        message: "Unexpected token",
+        stack: expect.any(String),
+        error: expect.any(Error),
+      }),
+    );
   });
 });