fix(admin): polish categories

Add accessible names to select-all, per-row select, and per-row
visibility-toggle checkboxes in the table view — none had them,
including the visibility toggle whose <label> wrapped only the input
with no text content (empty accessible name). Tree/grid views already
had aria-label on their row checkboxes; table view was the gap.

New adminCategories.selectAllRows/selectRow/toggleVisibility keys
added across en/ru/hy.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/i18n/translations.ts

@@ -1456,6 +1456,9 @@ export interface Translations {
     replaceImage: string;
     search: string;
     showDeleted: string;
+    selectAllRows: string;
+    selectRow: string;
+    toggleVisibility: string;
     create: string;
     edit: string;
     title: string;