feat: add remote products and qr code for payconic

lib/views/dialogs/close_tab_dialog.dart

@@ -64,7 +64,12 @@ Future<void> confirmCloseTab(BuildContext context) async {
     },
   );
 
-  if (confirmed != true) return;
+  if (confirmed != true || !context.mounted) return;
+
+  if (paymentMethod == PaymentMethod.payconiq) {
+    final paid = await _showPayconiqQr(context, tab.totalInCents.asEuro);
+    if (paid != true || !context.mounted) return;
+  }
 
   try {
     await viewModel.closeSelectedTab(paymentMethod: paymentMethod);
@@ -76,17 +81,62 @@ Future<void> confirmCloseTab(BuildContext context) async {
   }
 }
 
+const _payconiqQrAsset = 'assets/payconiq/qr.png';
+
+/// Shows the Payconiq QR code for the customer to scan. Resolves to true
+/// once the bartender taps Done; dismissing it leaves the tab open.
+Future<bool?> _showPayconiqQr(BuildContext context, String amount) {
+  final l10n = AppLocalizations.of(context);
+
+  return showDialog<bool>(
+    context: context,
+    builder: (dialogContext) {
+      return AlertDialog(
+        title: Text(l10n.payconiq),
+        content: SizedBox(
+          width: 360,
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              Text(l10n.scanToPay(amount), textAlign: TextAlign.center),
+              const SizedBox(height: 20),
+              ClipRRect(
+                borderRadius: BorderRadius.circular(12),
+                child: Image.asset(
+                  _payconiqQrAsset,
+                  width: 280,
+                  height: 280,
+                  fit: BoxFit.contain,
+                  errorBuilder: (context, _, _) => const SizedBox(
+                    width: 280,
+                    height: 280,
+                    child: Icon(Icons.qr_code_2, size: 160),
+                  ),
+                ),
+              ),
+              const SizedBox(height: 24),
+              SizedBox(
+                width: double.infinity,
+                child: FilledButton(
+                  onPressed: () => Navigator.of(dialogContext).pop(true),
+                  child: Text(l10n.done),
+                ),
+              ),
+            ],
+          ),
+        ),
+      );
+    },
+  );
+}
+
 class _PaymentPicker extends StatelessWidget {
   final PaymentMethod selected;
   final ValueChanged<PaymentMethod> onChanged;
 
   const _PaymentPicker({required this.selected, required this.onChanged});
 
-  static const _options = [
-    PaymentMethod.cash,
-    PaymentMethod.payconiq,
-    PaymentMethod.paymentPending,
-  ];
+  static const _options = [PaymentMethod.cash, PaymentMethod.payconiq];
 
   @override
   Widget build(BuildContext context) {