feat(auth): add remembered local login to the frontend

frontend/src/shell/WidgetHost.test.tsx

@@ -1,4 +1,4 @@
-import { render, screen } from "@testing-library/react";
+import { act, cleanup, render, screen } from "@testing-library/react";
 import { WidgetHost } from "./WidgetHost";
 import { useSessionStore } from "../store/sessionStore";
 import type { WidgetDescriptor } from "../api/types";
@@ -17,18 +17,19 @@ beforeEach(() => {
   useSessionStore.getState().resetSession();
 });
 afterEach(() => {
+  cleanup();
   errorSpy.mockRestore();
-  useSessionStore.getState().resetSession();
+  act(() => useSessionStore.getState().resetSession());
 });
 
 const gate: WidgetDescriptor = { id: "g1", widget: "select", title: "Choose" };
 
-test("a crashing widget shows a fallback instead of unmounting the app", () => {
+test("a crashing widget shows a fallback instead of unmounting the app", async () => {
   useSessionStore.setState({ pendingWidget: gate });
-  render(<WidgetHost sessionId="s1" />);
+  await act(async () => { render(<WidgetHost sessionId="s1" />); });
   // No throw escaped: the fallback rendered.
-  expect(screen.getByRole("alert")).toBeInTheDocument();
-  expect(screen.getByText(/couldn't be displayed/i)).toBeInTheDocument();
+  expect(await screen.findByRole("alert")).toBeInTheDocument();
+  expect(await screen.findByText(/couldn't be displayed/i)).toBeInTheDocument();
   // The store (and thus the surrounding app) is still alive and interactive.
   expect(useSessionStore.getState().pendingWidget).toEqual(gate);
 });