update gen qr

lib/core/constants/api_constants.dart

@@ -221,6 +221,12 @@ class ApiConstants {
   /// Body: { "transaction_date": "...", "delivery_date": "...", "items": [...], ... }
   static const String createOrder = '/building_material.building_material.api.sales_order.save';
 
+  /// Generate QR code for payment (requires sid and csrf_token)
+  /// POST /api/method/building_material.building_material.api.v1.qrcode.generate
+  /// Body: { "order_id": "SAL-ORD-2025-00048" }
+  /// Returns: { "message": { "qr_code": "...", "amount": null, "transaction_id": "...", "bank_info": {...} } }
+  static const String generateQrCode = '/building_material.building_material.api.v1.qrcode.generate';
+
   /// Get user's orders
   /// GET /orders?status={status}&page={page}&limit={limit}
   static const String getOrders = '/orders';

lib/core/router/app_router.dart

@@ -323,7 +323,10 @@ final routerProvider = Provider<GoRouter>((ref) {
           final amount = double.tryParse(amountStr) ?? 0.0;
           return MaterialPage(
             key: state.pageKey,
-            child: PaymentQrPage(orderId: orderId, amount: amount),
+            child: PaymentQrPage(
+              orderId: orderId,
+              amount: amount,
+            ),
           );
         },
       ),