added product import and billing integration

lib/presentation/pos/widgets/billing_panel.dart

@@ -7,6 +7,7 @@ import 'package:go_router/go_router.dart';
 import '../../../core/router/app_router.dart';
 import '../../../core/theme/app_colors.dart';
 import '../../../core/theme/app_dimens.dart';
+import '../../../core/theme/app_layout.dart';
 import '../../../core/theme/app_typography.dart';
 import '../../../core/utils/extensions.dart';
 import '../../../core/utils/formatters.dart';
@@ -15,6 +16,7 @@ import '../../../core/widgets/primary_button.dart';
 import '../../../domain/entities/cart.dart';
 import '../../customer/widgets/customer_capture_sheet.dart';
 import '../providers/cart_controller.dart';
+import 'admin_pin_dialog.dart';
 import 'cart_line_tile.dart';
 import 'discount_sheet.dart';
 
@@ -58,7 +60,12 @@ class BillingPanel extends ConsumerWidget {
                       line: line,
                       onIncrement: () => controller.increment(line.product.id),
                       onDecrement: () => controller.decrement(line.product.id),
-                      onRemove: () => controller.removeLine(line.product.id),
+                      onRemove: () => _removeLine(
+                        context,
+                        ref,
+                        controller,
+                        line.product.id,
+                      ),
                       onDiscount: () =>
                           showLineDiscountSheet(context, ref, line),
                     );
@@ -72,6 +79,37 @@ class BillingPanel extends ConsumerWidget {
   }
 }
 
+/// Once an item is on the bill, taking it back off needs an admin's
+/// approval — a cashier can always start an entirely new sale instead. This
+/// is the one gate both removal paths (a single line, or the whole cart) go
+/// through, so they can never drift out of sync with each other.
+Future<void> _removeLine(
+  BuildContext context,
+  WidgetRef ref,
+  CartController controller,
+  String productId,
+) async {
+  final ok = await requireAdminPin(
+    context,
+    ref,
+    reason: 'Removing a scanned item from the bill needs admin approval.',
+  );
+  if (ok) controller.removeLine(productId);
+}
+
+Future<void> _clearCart(
+  BuildContext context,
+  WidgetRef ref,
+  CartController controller,
+) async {
+  final ok = await requireAdminPin(
+    context,
+    ref,
+    reason: 'Clearing the whole bill needs admin approval.',
+  );
+  if (ok) controller.clear();
+}
+
 class _Header extends ConsumerWidget {
   const _Header({required this.cart, required this.inSheet});
 
@@ -81,15 +119,15 @@ class _Header extends ConsumerWidget {
   @override
   Widget build(BuildContext context, WidgetRef ref) {
     final controller = ref.read(cartControllerProvider.notifier);
+    // Same fixed height as the page header on the left, so the two bars
+    // line up on one visual line instead of the cart title floating lower.
+    final contentPadding = PosLayout.of(context).contentPadding;
 
-    return Padding(
-      padding: const EdgeInsets.fromLTRB(
-        AppSpacing.lg,
-        AppSpacing.md,
-        AppSpacing.sm,
-        AppSpacing.md,
-      ),
+    return Container(
+      constraints: const BoxConstraints(minHeight: AppSizes.headerHeight),
+      padding: EdgeInsets.symmetric(horizontal: contentPadding),
       child: Row(
+        mainAxisAlignment: MainAxisAlignment.spaceBetween,
         children: [
           Flexible(
             child: Text(
@@ -99,9 +137,9 @@ class _Header extends ConsumerWidget {
             ),
           ),
           if (cart.isNotEmpty) ...[
-            const SizedBox(width: AppSpacing.sm),
+
             Container(
-              padding: const EdgeInsets.symmetric(horizontal: 7, vertical: 2),
+              padding: const EdgeInsets.symmetric(horizontal: 4, vertical: 2),
               decoration: const BoxDecoration(
                 color: AppColors.primarySurface,
                 borderRadius: AppRadius.brPill,
@@ -116,40 +154,52 @@ class _Header extends ConsumerWidget {
               ),
             ),
           ],
-          const Spacer(),
+          SizedBox(),
+          SizedBox(),
+
+          Spacer(),
+
+
           // Icon-only actions: labelled buttons overflowed the 380px panel.
-          if (controller.canUndo)
-            _IconAction(
-              icon: Icons.undo_rounded,
-              tooltip: 'Undo (F8)',
-              color: AppColors.textSecondary,
-              onTap: controller.undo,
-            ),
-          if (cart.isNotEmpty) ...[
-            _IconAction(
-              icon: Icons.pause_circle_outline_rounded,
-              tooltip: 'Park bill',
-              color: AppColors.warning,
-              onTap: () async {
-                await controller.park();
-                ref.invalidate(parkedBillsProvider);
-                if (context.mounted) context.showSnack('Bill parked');
-              },
-            ),
-            _IconAction(
-              icon: Icons.delete_outline_rounded,
-              tooltip: 'Clear bill',
-              color: AppColors.danger,
-              onTap: controller.clear,
-            ),
-          ],
-          if (inSheet)
-            _IconAction(
-              icon: Icons.close_rounded,
-              tooltip: 'Close',
-              color: AppColors.textSecondary,
-              onTap: () => Navigator.of(context).pop(),
-            ),
+          // Grouped tight with even spacing, flush against the same right
+          // edge the header buttons on the left use.
+          Row(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              if (controller.canUndo)
+                _IconAction(
+                  icon: Icons.undo_rounded,
+                  tooltip: 'Undo (F8)',
+                  color: AppColors.textSecondary,
+                  onTap: controller.undo,
+                ),
+              if (cart.isNotEmpty) ...[
+                _IconAction(
+                  icon: Icons.pause_circle_outline_rounded,
+                  tooltip: 'Park bill',
+                  color: AppColors.warning,
+                  onTap: () async {
+                    await controller.park();
+                    ref.invalidate(parkedBillsProvider);
+                    if (context.mounted) context.showSnack('Bill parked');
+                  },
+                ),
+                _IconAction(
+                  icon: Icons.delete_outline_rounded,
+                  tooltip: 'Clear bill',
+                  color: AppColors.danger,
+                  onTap: () => _clearCart(context, ref, controller),
+                ),
+              ],
+              if (inSheet)
+                _IconAction(
+                  icon: Icons.close_rounded,
+                  tooltip: 'Close',
+                  color: AppColors.textSecondary,
+                  onTap: () => Navigator.of(context).pop(),
+                ),
+            ],
+          ),
         ],
       ),
     );
@@ -360,7 +410,9 @@ class _Row extends StatelessWidget {
   Widget build(BuildContext context) {
     return Padding(
       padding: const EdgeInsets.symmetric(vertical: AppSpacing.xs + 2),
-      child: Row(children: [
+      child: Row(
+        mainAxisAlignment: MainAxisAlignment.spaceBetween,
+        children: [
         Flexible(
           child: Text(
             label,
@@ -390,7 +442,7 @@ class _Row extends StatelessWidget {
           ),
         ),
         if (trailingIcon != null) ...[
-          const SizedBox(width: AppSpacing.xs),
+
           Icon(trailingIcon, size: 14, color: AppColors.textTertiary),
         ],
       ],),