a11y: keyboard-operable editor chrome + topbar aria-labels

Clickable <div> rows/tiles (page list, layer tree, template cards, asset
picker grid) now expose role="button", a tab stop, and Enter/Space
activation via a shared clickableProps() helper, matching their existing
onClick behavior. TopBar icon-only controls (device switcher, undo/redo,
save, publish, templates, code, preview, back) gain aria-label alongside
their existing title tooltips.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

craft/src/panels/topbar/TemplateModal.tsx

@@ -9,6 +9,7 @@ import {
   TemplateCategory,
 } from '../../templates';
 import { componentResolver } from '../../components/resolver';
+import { clickableProps } from '../../utils/a11y';
 
 // ---------------------------------------------------------------------------
 // Types
@@ -392,7 +393,7 @@ const TemplateCard: React.FC<{
 
   return (
     <div
-      onClick={onSelect}
+      {...clickableProps(onSelect)}
       onMouseEnter={() => setHovered(true)}
       onMouseLeave={() => setHovered(false)}
       style={{