feat(orders): PDF footer = issuer name+email, 'Zobrazit objednávku' button, per-currency list totals

- Issued-order PDF: drop the Vystavil/Schválil signature row; footer now shows
  'Vystavil: <name>' + 'E-mail: <email>' from the logged-in user (authData).
- IssuedOrderDetail PDF button 'Export PDF' -> 'Zobrazit objednávku' (already
  opens inline like invoices' 'Zobrazit fakturu').
- New /orders/stats + /issued-orders/stats endpoints sum order total (incl VAT)
  per currency across the active filter; rendered as 'Celkem: …' beneath both
  the received and issued lists. formatMultiCurrency lifted to a shared util.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/admin/pages/ReceivedOrders.tsx

@@ -7,12 +7,17 @@ import { useAlert } from "../context/AlertContext";
 import { useAuth } from "../context/AuthContext";
 import Forbidden from "../components/Forbidden";
 import apiFetch from "../utils/api";
-import { formatCurrency, formatDate } from "../utils/formatters";
+import {
+  formatCurrency,
+  formatDate,
+  formatMultiCurrency,
+} from "../utils/formatters";
 import useTableSort from "../hooks/useTableSort";
 import useDebounce from "../hooks/useDebounce";
 import { usePaginatedQuery } from "../hooks/usePaginatedQuery";
 import {
   orderListOptions,
+  orderStatsOptions,
   orderNextNumberOptions,
 } from "../lib/queries/orders";
 import { offerCustomersOptions } from "../lib/queries/offers";
@@ -317,6 +322,17 @@ export default function OrdersReceived({
     }),
   );
 
+  // Per-currency total over the WHOLE filtered set (not one page). Uses the
+  // SAME filters as the list query so the summary matches what's shown.
+  const statsQuery = useQuery(
+    orderStatsOptions({
+      search: debouncedSearch,
+      status: status || undefined,
+      month,
+      year,
+    }),
+  );
+
   // Mark first load done in an effect (not during render) to avoid a
   // render-phase ref mutation.
   useEffect(() => {
@@ -543,6 +559,27 @@ export default function OrdersReceived({
             )
           }
         />
+        {(statsQuery.data?.length ?? 0) > 0 && (
+          <Box
+            sx={{
+              display: "flex",
+              justifyContent: "flex-end",
+              mt: 1.5,
+              px: 1,
+              gap: 1,
+              color: "text.secondary",
+              fontSize: "0.9rem",
+            }}
+          >
+            <span>Celkem:</span>
+            <Box
+              component="span"
+              sx={{ fontWeight: 700, color: "text.primary" }}
+            >
+              {formatMultiCurrency(statsQuery.data ?? [])}
+            </Box>
+          </Box>
+        )}
         <Pagination
           page={page}
           pageCount={pagination?.total_pages ?? 1}