fix(nav): an item Back finds in another list is brought into view

frontend/src/lib/listNav.restoreMoved.dom.test.tsx

@@ -5,7 +5,7 @@
 // sits in the stream below. The restore matched the unnamed list by its place, missed the name there
 // and fell back to the saved index — the focus landed on the neighbour, and Enter opened the wrong
 // notification. Its own file: listNav keeps module-level state.
-import { afterEach, describe, expect, it } from "vitest";
+import { afterEach, describe, expect, it, vi } from "vitest";
 import { act, cleanup, render } from "@testing-library/react";
 import { useRef } from "react";
 
@@ -72,4 +72,21 @@ describe("Back to an item that moved to another list", () => {
     ]);
     expect(focused()).toBe("download");
   });
+
+  it("brings an item found in another list into view; one in its own list stays put", async () => {
+    // The scroll restore put the page where the item WAS: found elsewhere, it would hold the focus
+    // off screen.
+    const reveal = vi.fn();
+    Element.prototype.scrollIntoView = reveal;
+    await leaveAndReturn([["subscribed", "download"], ["older"]], "subscribed", [
+      ["download"],
+      ["subscribed", "older"],
+    ]);
+    expect(reveal).toHaveBeenCalledTimes(1);
+    cleanup();
+    reveal.mockClear();
+    await leaveAndReturn([["subscribed", "download"]], "download", [["download", "subscribed"]]);
+    expect(focused()).toBe("download");
+    expect(reveal).not.toHaveBeenCalled();
+  });
 });