refactor: align frontend ownership boundaries

Close audit gaps across API drift, query policy, UI, and tests.

src/test/setup.ts

@@ -1,10 +1,16 @@
 import "@testing-library/jest-dom/vitest";
+import { cleanup } from "@testing-library/react";
 import { afterAll, afterEach, beforeAll } from "vitest";
+import { configureAuthClient } from "@/shared/api";
 import "../shared/i18n";
 import { server } from "./server";
 
 beforeAll(() => server.listen({ onUnhandledRequest: "error" }));
-afterEach(() => server.resetHandlers());
+afterEach(() => {
+	cleanup();
+	configureAuthClient(null);
+	server.resetHandlers();
+});
 afterAll(() => server.close());
 
 class ResizeObserver {