fix(admin): polish products

Add accessible names to the table-view select-all and per-row
checkboxes — they had none, while the grid-view equivalent already
did (product name via aria-label). New adminProducts.selectAllRows/
selectRow keys added across en/ru/hy.

Reviewed toolbar, filters, bulk actions, empty/loading states, and
grid view: all buttons already route through app-button (own
:focus-visible), empty state already uses shared EmptyStateComponent.
No orphaned bindings or corrupted glyphs found.

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

src/app/i18n/en.ts

@@ -1531,6 +1531,8 @@ export const en: Translations = {
     emptyTitle: 'No products found',
     emptyDescription: 'Try adjusting your filters, or create a new product.',
     emptyGuide: 'Good products have a clear title, at least one photo, a price, and a short description — that\'s enough to publish. You can always add more detail later.',
+    selectAllRows: 'Select all products',
+    selectRow: 'Select product',
     search: 'Search products…',
     category: 'Category',
     allCategories: 'All categories',