feat(client): improve accessibility with ARIA labels and semantics

- Add aria-label to icon-only ActionIcon triggers across tree, comments,
  share, group, breadcrumbs, templates, AI chat, API keys, and spaces
- Give custom clickable divs/spans (color swatches, status swatches,
  load-more, PDF error, comment selection) role="button", tabIndex,
  and keyboard handlers
- Add listbox/combobox semantics (role, aria-selected, aria-activedescendant)
  to slash menu, emoji menu, mention list, and link editor results
- Add aria-haspopup/aria-expanded to bubble-menu triggers (node, text
  align, color) and status badge
- Add aria-label to Modal.Root/Dialog instances that lack a title prop
  (page history, template preview, trash preview, drawio, comment,
  find-and-replace, page verification)
- Add en-US translations for new aria-label strings

apps/client/src/features/page-history/components/history-modal.tsx

@@ -22,6 +22,7 @@ export default function HistoryModal({ pageId, pageTitle }: Props) {
         opened={isModalOpen}
         onClose={() => setModalOpen(false)}
         fullScreen
+        aria-label={t("Page history")}
       >
         <Modal.Overlay />
         <Modal.Content style={{ overflow: "hidden" }}>
@@ -49,6 +50,7 @@ export default function HistoryModal({ pageId, pageTitle }: Props) {
       size={1400}
       opened={isModalOpen}
       onClose={() => setModalOpen(false)}
+      aria-label={t("Page history")}
     >
       <Modal.Overlay />
       <Modal.Content style={{ overflow: "hidden" }}>