Surface setup error state instead of console.warn in useSetup

frontend/src/pages/__tests__/SetupPage.test.tsx

@@ -67,9 +67,7 @@ describe("SetupPage", () => {
     });
   });
 
-  it("renders the form and logs a warning when the status check fails", async () => {
-    // Task 0.4: catch block must log a warning and keep the form visible.
-    const warnSpy = vi.spyOn(console, "warn").mockImplementation(() => {});
+  it("renders the form and surfaces the error message when the status check fails", async () => {
     mockedGetSetupStatus.mockRejectedValue(new Error("Connection refused"));
     renderPage();
     await waitFor(() => {
@@ -77,7 +75,6 @@ describe("SetupPage", () => {
         screen.getByRole("heading", { name: /bangui setup/i }),
       ).toBeInTheDocument();
     });
-    expect(warnSpy).toHaveBeenCalledOnce();
-    warnSpy.mockRestore();
+    expect(screen.getByText(/connection refused/i)).toBeInTheDocument();
   });
 });