fix(ui): focus, paging and state that a key or a finger can reach

- A key landing on a side panel's tab steps into the card it peeks open, not onto the hidden tab.
- The Channels cards keep their status / pager row at the list's end while the band is folded.
- A menu row's note shows on an enabled row too: the download state under 'Download…', not a title.
- A removal chip hands the focus to its neighbour before it goes, for every caller (the feed's and
  Plex's active filters); the hidden-filter cue's own copy is gone.
- Back to a spot within a page's end spacer lands at the page's end, not its top.
- A running push / revert is tracked per list: another list's push is no longer refused unseen.

frontend/src/components/ui/SidePanel.drawer.dom.test.tsx

@@ -6,7 +6,7 @@
 // hover-to-peek and click-to-pin. jsdom has no matchMedia: the stub answers the two queries SidePanel
 // asks from three switches, and can flip them live (a tablet turning).
 import { describe, it, expect, afterEach, vi } from "vitest";
-import { act, render, screen, fireEvent, cleanup } from "@testing-library/react";
+import { act, render, screen, fireEvent, cleanup, waitFor } from "@testing-library/react";
 
 vi.mock("react-i18next", async (importOriginal) => {
   const actual = await importOriginal<typeof import("react-i18next")>();
@@ -105,6 +105,21 @@ describe("SidePanel · the tab under an open card", () => {
     mount(true);
     expect(screen.getByRole("button", { name: "sidebar.pinNamed:Filters" }).tabIndex).toBe(0);
   });
+
+  it("hands a key's focus on the tab to the card it peeks open, not to the hidden tab", async () => {
+    stubMedia({ coarse: false, narrow: false, wide: true });
+    globalThis.ResizeObserver ??= class {
+      observe() {}
+      unobserve() {}
+      disconnect() {}
+    } as unknown as typeof ResizeObserver;
+    mount(true);
+    const tab = screen.getByRole("button", { name: "sidebar.pinNamed:Filters" });
+    act(() => tab.focus()); // jsdom calls every focus :focus-visible — a key's focus, here
+    await waitFor(() => expect(document.activeElement?.closest("aside")).not.toBeNull());
+    expect(document.activeElement?.getAttribute("aria-label")).toBe("sidebar.pinNamed:Filters");
+    expect(document.activeElement).not.toBe(tab);
+  });
 });
 
 describe("SidePanel · on touch", () => {