fix(settings): handle preferences fetch failure instead of hanging

src/app/(app)/settings/__tests__/page.test.tsx

@@ -0,0 +1,59 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { render, screen, cleanup, waitFor } from "@testing-library/react";
+import SettingsPage from "../page";
+
+vi.mock("next/navigation", () => ({ useRouter: () => ({ refresh: vi.fn() }) }));
+vi.mock("sonner", () => ({ toast: { success: vi.fn(), error: vi.fn() } }));
+vi.mock("@/components/providers/theme-provider", () => ({
+  useTheme: () => ({
+    preferences: {
+      accentTheme: "amber",
+      fontStyle: "sans",
+      layoutDensity: "default",
+      currency: "USD",
+      weekStart: "monday",
+      dateFormat: "MMM d, yyyy",
+      timeFormat: "24h",
+      colorMode: "system",
+    },
+    updatePreferences: vi.fn(),
+  }),
+}));
+vi.mock("@/components/providers/sections-provider", () => ({
+  useSections: () => ({
+    enabledSections: [],
+    customSections: [],
+    updateSections: vi.fn(),
+    updateCustomSections: vi.fn(),
+  }),
+}));
+
+import { toast } from "sonner";
+
+describe("SettingsPage", () => {
+  beforeEach(() => {
+    global.fetch = vi.fn((url: string) => {
+      if (url === "/api/user/preferences") {
+        return Promise.reject(new Error("network error"));
+      }
+      return Promise.resolve({ ok: true, json: async () => ({ shares: [] }) });
+    }) as unknown as typeof fetch;
+  });
+
+  afterEach(() => {
+    cleanup();
+    vi.restoreAllMocks();
+  });
+
+  it("clears the loading skeleton and surfaces an error when the preferences fetch fails", async () => {
+    render(<SettingsPage />);
+
+    // Loaded-branch-only content must not be present while loading.
+    expect(screen.queryByText("Personalize your planner")).not.toBeInTheDocument();
+
+    await waitFor(() =>
+      expect(screen.getByText("Personalize your planner")).toBeInTheDocument()
+    );
+    expect(toast.error).toHaveBeenCalledWith("Failed to load settings");
+  });
+});

src/app/(app)/settings/page.tsx

@@ -123,8 +123,11 @@ export default function SettingsPage() {
         setTargetDaysPerWeek(data.gymConfig?.targetDaysPerWeek ?? 3);
         setAiProviderSetting(data.aiProvider || "");
         setHasAiKey(data.hasAiKey || false);
-        setLoading(false);
-      });
+      })
+      .catch(() => {
+        toast.error("Failed to load settings");
+      })
+      .finally(() => setLoading(false));
   }, []);
 
   useEffect(() => {