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/ActionMenu.tsx

@@ -27,14 +27,12 @@ const ROW =
   "flex w-full items-center gap-2.5 rounded-lg px-2 py-1.5 text-left text-sm outline-hidden transition";
 const dim = (disabled: boolean | undefined) => (disabled ? " opacity-50" : "");
 
-/** The label, and under it — on a disabled row only — the reason it is off. */
+/** The label, and under it the row's note: why it is off, or the state of what it opens. */
 function RowLabel({ item }: { item: MenuItemBase }) {
   return (
     <span className="min-w-0 flex-1">
       <span className={`block truncate${dim(item.disabled)}`}>{item.label}</span>
-      {item.disabled && item.note && (
-        <span className="block text-2xs leading-snug text-muted">{item.note}</span>
-      )}
+      {item.note && <span className="block text-2xs leading-snug text-muted">{item.note}</span>}
     </span>
   );
 }
@@ -50,7 +48,9 @@ interface MenuItemBase {
    *  fires no pointer events (no tooltip) and roving focus skips it, so a reason there reached
    *  nobody. An `aria-disabled` row was tried and reverted (E10 review rounds 1–2: floating-ui skips
    *  it identically, and the mouse got a highlight that then no-opped). Visible text is the one
-   *  place a disabled row's reason can be: seen, and read in a screen reader's browse mode. */
+   *  place a disabled row's reason can be: seen, and read in a screen reader's browse mode.
+   *  On an ENABLED row it is the state of what the row opens ("Downloaded" under "Download…"),
+   *  for the same reason: a `title` shows to a resting mouse only (round 2, F5). */
   note?: string;
   /** Draw a divider above this item. Ignored on the first item — a menu never opens with a rule. */
   separatorBefore?: boolean;