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.tsx

@@ -160,6 +160,15 @@ export default function SidePanel({
                   );
               }
         }
+        // A key landing on the tab peeks the card open over it, and the tab then goes inert below —
+        // with the focus still on it: a hidden control, out of the tree, that Enter still pinned
+        // (round 2, F1). The focus steps into the card instead, onto its pin: the same control.
+        onFocus={(e) => {
+          if (drawerMode || pinned || !e.currentTarget.matches(":focus-visible")) return;
+          requestAnimationFrame(() =>
+            cardRef.current?.querySelector<HTMLElement>("button")?.focus(),
+          );
+        }}
         // Under an open card the tab is transparent and inert: out of the Tab order AND of the
         // accessibility tree, where it would repeat the card's own pin button by name.
         tabIndex={expanded ? -1 : undefined}