updates

Frontend/src/pages/staff/LoyaltyManagementPage.tsx

@@ -1,17 +1,13 @@
 import React, { useState, useEffect } from 'react';
 import { 
-  Star, 
   Award, 
   Users, 
   Search,
   Filter,
-  TrendingUp,
   Gift,
-  RefreshCw,
   Edit,
   Trash2,
   Plus,
-  Settings,
   Power,
   PowerOff,
   X,
@@ -721,7 +717,7 @@ const LoyaltyManagementPage: React.FC = () => {
                           <span className="text-lg font-bold text-indigo-600">
                             {reward.points_cost} points
                           </span>
-                          {reward.stock_quantity !== null && (
+                          {reward.stock_quantity != null && reward.redeemed_count != null && (
                             <span className="text-sm text-gray-500">
                               {reward.stock_quantity - reward.redeemed_count} left
                             </span>