feat(invoices/orders): confirm before paid, draft PDF gate, debounced search, distinct create labels

- Marking an invoice paid (issued + received lists) now confirms via
  ConfirmDialog with loading guard — was a single unguarded chip click on a
  terminal transition; chips got affordance tooltips.
- Invoices list PDF icon hidden for drafts (no number → /file 404s),
  matching Offers/IssuedOrders.
- Search debounced (300ms) on Invoices/ReceivedInvoices (list + totals).
- Orders tabs create buttons renamed 'Nová vydaná/přijatá objednávka'
  (were identical for two document types); issued empty-state CTA aligned;
  draft delete dialog uses documentNumberLabel.

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

src/admin/pages/IssuedOrders.tsx

@@ -436,7 +436,7 @@ export default function IssuedOrders({ month, year }: IssuedOrdersProps) {
                 action={
                   hasPermission("orders.create") ? (
                     <Button component={RouterLink} to="/orders/issued/new">
-                      Vytvořit objednávku
+                      Nová vydaná objednávka
                     </Button>
                   ) : undefined
                 }