feat(F-189): completed feature

project/apps/pos/src/app/(terminal)/page.tsx

@@ -5,6 +5,7 @@ import DiscountPanel from '@/components/DiscountPanel';
 import FreeItemModal from '@/components/FreeItemModal';
 import PaymentModal from '@/components/PaymentModal';
 import ReceiptModal from '@/components/ReceiptModal';
+import ReturnModal from '@/components/ReturnModal';
 import { posApi } from '@/lib/api-client';
 import { generateIdempotencyKey } from '@/lib/idempotency';
 import { formatPrice } from '@/lib/money';
@@ -112,6 +113,9 @@ export default function RegisterPage() {
   const [loadingPending, setLoadingPending] = useState(false);
   const [restPaymentFor, setRestPaymentFor] = useState<PosPendingSale | null>(null);
   const [processingRest, setProcessingRest] = useState(false);
+  const [returnOrder, setReturnOrder] = useState<{ orderId: string; receipt: PosReceipt } | null>(
+    null,
+  );
 
   const loadConfig = useCallback(async () => {
     setConfigError('');
@@ -1163,6 +1167,26 @@ export default function RegisterPage() {
           receipt={receipt}
           initialEmail={customer?.email ?? receipt.customerEmail ?? ''}
           onDelivered={resetCashier}
+          onReturn={
+            config?.session && config?.terminal
+              ? (orderId, latest) => {
+                  setReturnOrder({ orderId, receipt: latest });
+                }
+              : undefined
+          }
+        />
+      )}
+      {returnOrder && config?.session && config?.terminal && (
+        <ReturnModal
+          receipt={returnOrder.receipt}
+          orderId={returnOrder.orderId}
+          cashSessionId={config.session.id}
+          terminalId={config.terminal.id}
+          onClose={() => setReturnOrder(null)}
+          onReturned={(latest) => {
+            setReturnOrder(null);
+            setReceipt(latest);
+          }}
         />
       )}
     </div>