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/panelEscape.test.mjs

@@ -42,7 +42,7 @@ function panelFixture({ id = 'data-panel', nested = false, nestedCollapsed = fal
     disclosure.closest = () => panel;
   }
   const document = { getElementById: (candidate) => candidate === id ? panel : null };
-  const manager = new Function('document', 'collapsePanelOnEscape', `return {${method('_collapsePanelOnEscape', '_initCommandDockPins')}};`)(document, collapsePanelOnEscape);
+  const manager = new Function('document', 'getComputedStyle', 'collapsePanelOnEscape', `return {${method('_collapsePanelOnEscape', '_initCommandDockPins')}};`)(document, (el) => ({ visibility: el.visibility ?? 'visible' }), collapsePanelOnEscape);
   manager.setPanelCollapsed = (candidate, value, options) => {
     assert.equal(candidate, id);
     assert.equal(value, true);
@@ -55,7 +55,7 @@ function panelFixture({ id = 'data-panel', nested = false, nestedCollapsed = fal
     stopPropagation() { this.propagationStopped = true; },
   };
   return {
-    manager, panel, inner, target, event,
+    manager, panel, inner, target, event, document,
     collapsed: () => collapsed,
     focused: () => focused,
     blurred: () => blurred,
@@ -71,6 +71,41 @@ test('Escape collapses an expanded panel and returns focus to its disclosure', (
   assert.equal(fixture.event.propagationStopped, true);
 });
 
+test('Escape hands focus to the rail item when collapsing hides the panel', () => {
+  const fixture = panelFixture();
+  let railFocused = false;
+  const railItem = {
+    disabled: false,
+    getClientRects: () => [{}],
+    focus: () => { railFocused = true; },
+  };
+  fixture.panel.getClientRects = () => (fixture.collapsed() ? [] : [{}]);
+  fixture.document.querySelector = (selector) => {
+    assert.equal(selector, '.ui-rail [data-rail-item="data-panel"]');
+    return railItem;
+  };
+  assert.equal(fixture.manager._collapsePanelOnEscape(fixture.event, 'data-panel'), true);
+  assert.equal(fixture.collapsed(), true);
+  assert.equal(railFocused, true);
+  assert.equal(fixture.focused(), false, 'not the hidden disclosure');
+});
+
+test('Escape keeps the disclosure path when the rail is hidden', () => {
+  const fixture = panelFixture();
+  let railFocused = false;
+  const railItem = {
+    disabled: false,
+    visibility: 'hidden',
+    getClientRects: () => [{}],
+    focus: () => { railFocused = true; },
+  };
+  fixture.panel.getClientRects = () => (fixture.collapsed() ? [] : [{}]);
+  fixture.document.querySelector = () => railItem;
+  assert.equal(fixture.manager._collapsePanelOnEscape(fixture.event, 'data-panel'), true);
+  assert.equal(railFocused, false);
+  assert.equal(fixture.focused(), true);
+});
+
 test('Escape on an expanded panel disclosure closes it without retaining focus', () => {
   const fixture = panelFixture({ onDisclosure: true });
   assert.equal(fixture.manager._collapsePanelOnEscape(fixture.event, 'data-panel'), true);