fix(ui): return Escape focus to the rail item and read rail direction from the panel

A desktop side panel hides once collapsed, so Escape hands focus to its visible rail item instead of the hidden disclosure. Rail selection reads the panel's collapsed class rather than the store, which follows it a microtask late.

src/ui/panelDisclosure.js

@@ -39,10 +39,14 @@ export function bindPanelDisclosure({
   return { destroy: () => scope.destroy() };
 }
 
-/** Close the nearest expanded panel and return focus to its disclosure. */
+/**
+ * Close the nearest expanded panel and return focus to its disclosure, or to
+ * `returnFocusTo()` when that names a control (a rail item standing in for a
+ * panel that collapsing hid).
+ */
 export function collapsePanelOnEscape(
   event,
-  { panel, onChange, beforeCollapse },
+  { panel, onChange, beforeCollapse, returnFocusTo },
 ) {
   if (event.key !== 'Escape' || event.defaultPrevented) return false;
   if (
@@ -59,6 +63,11 @@ export function collapsePanelOnEscape(
   event.stopPropagation();
   beforeCollapse?.();
   onChange(true, { explicit: true });
+  const stand = returnFocusTo?.();
+  if (stand) {
+    stand.focus?.({ preventScroll: true });
+    return true;
+  }
   const disclosure =
     panel.querySelector(`[data-dock-toggle-target="${panel.id}"]`) ||
     panel.querySelector(`[data-collapse-target="${panel.id}"]`);