fix(admin): polish orders

Same gap as products/categories: table select-all and per-row select
checkboxes had no accessible name. Added aria-label (row label
includes order number for context). New adminOrders.selectAllRows/
selectRow keys across en/ru/hy.

Order detail page and order-timeline component reviewed — no
interactive checkboxes or focus-visible gaps found there.

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

src/app/i18n/en.ts

@@ -1292,6 +1292,8 @@ export const en: Translations = {
     back: 'Back to orders',
     search: 'Search by order number, name, email, or phone…',
     export: 'Export',
+    selectAllRows: 'Select all orders',
+    selectRow: 'Select order',
     view: 'View',
     orderNumber: 'Order',
     customer: 'Customer',