fix(player): a layer that opens by itself takes no history entry

The auto-skip countdown and the up-next card pushed an entry without a
user gesture (Chrome's Back button skips those), and one pushed under the
open shortcuts sheet sat above it, so Back closed the hidden layer.

frontend/src/components/PlexPlayer.session.dom.test.tsx

@@ -308,6 +308,45 @@ describe("leaving an item that was played through", () => {
     act(() => void el.dispatchEvent(new Event("ended")));
   };
 
+  // A layer the player opens BY ITSELF — the auto-skip countdown, the up-next card — takes no history
+  // entry. Chrome's Back button skips an entry pushed without a user gesture, and one pushed under an
+  // open dialog (the shortcuts sheet) sat above it, so Back closed the hidden layer, not the dialog.
+  const overlayPushes = (push: { mock: { calls: unknown[][] } }) =>
+    push.mock.calls.filter(([state]) => (state as { _ov?: number } | null)?._ov != null);
+
+  it("gives the auto-skip countdown no history entry", async () => {
+    prefs({ autoSkipIntro: true, autoSkipDelay: 5 });
+    const withIntro = {
+      ...item("A"),
+      markers: [{ type: "intro", start_s: 100, end_s: 160, final: false }],
+    } as unknown as PlexItemDetail;
+    mount({ details: { A: withIntro }, sessions: { A: () => Promise.resolve(direct("A")) } });
+    await playingAt("/media/A", 50);
+    await tick();
+    const push = vi.spyOn(window.history, "pushState");
+    await playingAt("/media/A", 110); // inside the intro: the countdown starts
+    await waitFor(() => expect(screen.getByText("plex.player.skipIntro")).toBeTruthy());
+    await tick();
+    expect(overlayPushes(push)).toEqual([]);
+  });
+
+  it("gives the up-next card no history entry", async () => {
+    prefs({ upNext: true });
+    mount({
+      details: { A: item("A"), B: item("B") },
+      sessions: { A: () => Promise.resolve(direct("A")), B: () => new Promise(() => {}) },
+      queue: ["A", "B"],
+    });
+    vi.spyOn(api, "plexSetState").mockResolvedValue(undefined as never);
+    await playingAt("/media/A", 2995);
+    await tick();
+    const push = vi.spyOn(window.history, "pushState");
+    endMedia();
+    await screen.findByText("Title B"); // the card names the next item
+    await tick();
+    expect(overlayPushes(push)).toEqual([]);
+  });
+
   it("settles it as watched when it ended, so Prev does not reopen it at its last seconds", async () => {
     prefs({ upNext: false });
     const { qc, progress } = mount({