test: the boundary stays quiet while reloading for a new build; Back restores Home's whole question

frontend/src/components/ErrorBoundary.staleBuild.dom.test.tsx

@@ -0,0 +1,44 @@
+// @vitest-environment jsdom
+//
+// A tab reloading onto a newer build (lib/staleBuild) renders the chunk it could not load as a render
+// error: the boundary must neither report it as a crash (a fatal notice outlives the reload) nor flash
+// the crash screen before the reload lands. Its own file: staleBuild's "reloading" flag is module state
+// and never turns back off.
+import { afterEach, expect, it, vi } from "vitest";
+import { cleanup, render } from "@testing-library/react";
+
+const notify = vi.fn();
+vi.mock("../lib/notifications", () => ({ notify: (...args: unknown[]) => notify(...args) }));
+
+import { clear, events } from "../lib/log";
+import { installStaleBuildReload } from "../lib/staleBuild";
+import ErrorBoundary from "./ErrorBoundary";
+
+afterEach(() => {
+  cleanup();
+  clear();
+  vi.restoreAllMocks();
+});
+
+it("a missing chunk while reloading for a new build is no crash: nothing reported, nothing shown", () => {
+  vi.spyOn(console, "error").mockImplementation(() => {}); // React reports the throw itself too
+  sessionStorage.clear();
+  const reload = vi.fn();
+  const uninstall = installStaleBuildReload(reload);
+  window.dispatchEvent(new Event("vite:preloadError", { cancelable: true }));
+  uninstall();
+  expect(reload).toHaveBeenCalledOnce();
+
+  const Missing = () => {
+    throw new Error("Failed to fetch dynamically imported module");
+  };
+  const { container } = render(
+    <ErrorBoundary>
+      <Missing />
+    </ErrorBoundary>,
+  );
+
+  expect(events().filter((e) => e.event === "ui.crash")).toEqual([]);
+  expect(notify).not.toHaveBeenCalled();
+  expect(container.innerHTML).toBe("");
+});

frontend/src/components/Home.dom.test.tsx

@@ -575,13 +575,18 @@ describe("Home", () => {
     fireEvent.click(screen.getByText("home.budget.short"));
     fireEvent.click(screen.getByText("home.hero.reroll"));
     expect(await screen.findByText("Rerolled")).toBeTruthy();
+    const asked = discoverPick.mock.lastCall;
     first.unmount();
 
     discover.mockClear();
+    discoverPick.mockClear();
     mount();
 
     expect(await screen.findByText("Rerolled")).toBeTruthy();
     expect(discover).toHaveBeenLastCalledWith("short", 0);
+    // The very same question — seed, the cards already seen and the press count all came back, not
+    // just the budget: the server answers each of them differently.
+    await waitFor(() => expect(discoverPick.mock.lastCall).toEqual(asked));
   });
 
   // Measured in the browser (2026-09-07), before the fix: the palette's "Meglepetés" arrived at Home