fix(shopinbit): require a live invoice before opening the payment view

diff --git a/lib/pages/shopinbit/shopinbit_payment_view.dart b/lib/pages/shopinbit/shopinbit_payment_view.dart
index af80536..8f4105c 100644
--- a/lib/pages/shopinbit/shopinbit_payment_view.dart
+++ b/lib/pages/shopinbit/shopinbit_payment_view.dart
@@ -32,16 +32,15 @@ class ShopInBitPaymentView extends ConsumerStatefulWidget {
   const ShopInBitPaymentView({
     super.key,
     required this.model,
-    this.initialPaymentInfo,
+    required this.paymentInfo,
   });
 
   static const String routeName = "/shopInBitPayment";
 
   final ShopInBitOrderModel model;
 
-  // Pre-loaded by the caller (see fetchShopInBitPaymentInfo) so the view can
-  // render populated immediately instead of fetching after it's pushed.
-  final PaymentInfo? initialPaymentInfo;
+  // Caller loads this before pushing, so we always open with usable addresses.
+  final PaymentInfo paymentInfo;
 
   @override
   ConsumerState<ShopInBitPaymentView> createState() =>
@@ -80,27 +79,10 @@ class _ShopInBitPaymentViewState extends ConsumerState<ShopInBitPaymentView> {
   @override
   void initState() {
     super.initState();
-    if (widget.initialPaymentInfo != null) {
-      _applyPaymentInfo(widget.initialPaymentInfo!);
-    }
+    _applyPaymentInfo(widget.paymentInfo);
     if (widget.model.apiTicketId != 0) {
-      // If the pre-load didn't hand us usable payment links, recover them:
-      // GET, then PUT to generate one.
-      if (_addresses.every((a) => a.isEmpty)) {
-        unawaited(_recoverPaymentInfo());
-      } else {
-        _startPolling();
-      }
-    }
-  }
-
-  Future<void> _recoverPaymentInfo() async {
-    final info = await fetchShopInBitPaymentInfo(ref, widget.model.apiTicketId);
-    if (!mounted) return;
-    if (info != null) {
-      setState(() => _applyPaymentInfo(info));
+      _startPolling();
     }
-    _startPolling();
   }
 
   @override
@@ -289,6 +271,7 @@ class _ShopInBitPaymentViewState extends ConsumerState<ShopInBitPaymentView> {
 
   void _onOwnedCoinTap(int methodIndex) {
     if (!_payNowEnabled) return;
+    if (_addresses[methodIndex].isEmpty) return;
     _selectedMethod = methodIndex;
     unawaited(_confirmPayment());
   }
@@ -362,14 +345,14 @@ class _ShopInBitPaymentViewState extends ConsumerState<ShopInBitPaymentView> {
     for (int i = 0; i < _methods.length; i++) {
       final ticker = _methods[i].toUpperCase();
       final coin = AppConfig.getCryptoCurrencyForTicker(ticker);
+      final hasAddress = _addresses[i].isNotEmpty;
       final hasWallet = hasShopInBitWalletForTicker(
         wallets: wallets,
         ticker: ticker,
         paymentUri: _addresses[i],
       );
-      final amountStr = _addresses[i].isNotEmpty
-          ? _parseBip21Amount(_addresses[i])
-          : null;
+      final canPayNow = hasWallet && hasAddress;
+      final amountStr = hasAddress ? _parseBip21Amount(_addresses[i]) : null;
 
       if (i > 0) {
         coinRows.add(const SizedBox(height: 8));
@@ -378,11 +361,13 @@ class _ShopInBitPaymentViewState extends ConsumerState<ShopInBitPaymentView> {
       coinRows.add(
         RoundedWhiteContainer(
           child: Opacity(
-            opacity: hasWallet ? 1.0 : 0.5,
+            opacity: canPayNow ? 1.0 : 0.5,
             child: InkWell(
-              onTap: hasWallet
-                  ? () => _onOwnedCoinTap(i)
-                  : () => _onUnownedCoinTap(i),
+              onTap: !hasAddress
+                  ? null
+                  : (hasWallet
+                        ? () => _onOwnedCoinTap(i)
+                        : () => _onUnownedCoinTap(i)),
               child: Row(
                 children: [
                   if (coin != null)
@@ -419,7 +404,7 @@ class _ShopInBitPaymentViewState extends ConsumerState<ShopInBitPaymentView> {
                       ],
                     ),
                   ),
-                  if (hasWallet)
+                  if (canPayNow)
                     Text("PAY NOW", style: STextStyles.link2(context))
                   else
                     SvgPicture.asset(
diff --git a/lib/pages/shopinbit/shopinbit_shipping_view.dart b/lib/pages/shopinbit/shopinbit_shipping_view.dart
index d62e9b4..88be18d 100644
--- a/lib/pages/shopinbit/shopinbit_shipping_view.dart
+++ b/lib/pages/shopinbit/shopinbit_shipping_view.dart
@@ -20,6 +20,7 @@ import '../../widgets/detail_item.dart';
 import '../../widgets/desktop/desktop_dialog_close_button.dart';
 import '../../widgets/desktop/primary_button.dart';
 import '../../widgets/dialogs/s_dialog.dart';
+import '../../widgets/stack_dialog.dart';
 import '../../widgets/textfields/adaptive_text_field.dart';
 import 'shopinbit_payment_shared.dart';
 import 'shopinbit_payment_view.dart';
@@ -194,70 +195,84 @@ class _ShopInBitShippingViewState extends ConsumerState<ShopInBitShippingView> {
     // and the user picked one here.
     widget.model.deliveryCountry = country;
 
-    // Pre-load the payment info before pushing the payment view so it renders
-    // populated immediately. The Continue button's spinner (_submitting)
-    // already covers this wait.
+    // The payment view needs a live invoice, so load it here and only navigate
+    // once we have usable payment links.
+    if (widget.model.apiTicketId == 0) {
+      // No ticket, nothing to invoice.
+      await _showPaymentLoadError(
+        "This request isn't ready for payment yet. Please try again.",
+      );
+      return;
+    }
+
     PaymentInfo? paymentInfo;
-    if (widget.model.apiTicketId != 0) {
-      setState(() => _submitting = true);
-      try {
-        // Split name into first/last
-        final parts = name.split(' ');
-        final firstName = parts.first;
-        final lastName = parts.length > 1 ? parts.sublist(1).join(' ') : '';
-
-        Address? billingAddress;
-        if (_differentBilling) {
-          final billingName = _billingNameController.text.trim();
-          final billingParts = billingName.split(' ');
-          final billingFirst = billingParts.first;
-          final billingLast = billingParts.length > 1
-              ? billingParts.sublist(1).join(' ')
-              : '';
-          billingAddress = Address(
-            firstName: billingFirst,
-            lastName: billingLast,
-            street: _billingStreetController.text.trim(),
-            zip: _billingPostalCodeController.text.trim(),
-            city: _billingCityController.text.trim(),
-            country: _billingSelectedCountryIso!,
-          );
-        }
-
-        final resp = await ref
-            .read(pShopinBitService)
-            .client
-            .submitAddress(
-              widget.model.apiTicketId,
-              shipping: Address(
-                firstName: firstName,
-                lastName: lastName,
-                street: street,
-                zip: postalCode,
-                city: city,
-                country: country,
-              ),
-              billing: billingAddress,
-            );
+    setState(() => _submitting = true);
+    try {
+      // Split name into first/last
+      final parts = name.split(' ');
+      final firstName = parts.first;
+      final lastName = parts.length > 1 ? parts.sublist(1).join(' ') : '';
+
+      Address? billingAddress;
+      if (_differentBilling) {
+        final billingName = _billingNameController.text.trim();
+        final billingParts = billingName.split(' ');
+        final billingFirst = billingParts.first;
+        final billingLast = billingParts.length > 1
+            ? billingParts.sublist(1).join(' ')
+            : '';
+        billingAddress = Address(
+          firstName: billingFirst,
+          lastName: billingLast,
+          street: _billingStreetController.text.trim(),
+          zip: _billingPostalCodeController.text.trim(),
+          city: _billingCityController.text.trim(),
+          country: _billingSelectedCountryIso!,
+        );
+      }
 
-        if (resp.hasError) {
-          // Sandbox may fail here; continue anyway.
-          debugPrint("submitAddress failed: ${resp.exception?.message}");
-        }
+      final resp = await ref
+          .read(pShopinBitService)
+          .client
+          .submitAddress(
+            widget.model.apiTicketId,
+            shipping: Address(
+              firstName: firstName,
+              lastName: lastName,
+              street: street,
+              zip: postalCode,
+              city: city,
+              country: country,
+            ),
+            billing: billingAddress,
+          );
 
-        paymentInfo = await fetchShopInBitPaymentInfo(
-          ref,
-          widget.model.apiTicketId,
-        );
-      } catch (e) {
-        debugPrint("submitAddress threw: $e");
-      } finally {
-        if (mounted) setState(() => _submitting = false);
+      if (resp.hasError) {
+        // Sandbox may fail here; continue anyway.
+        debugPrint("submitAddress failed: ${resp.exception?.message}");
       }
+
+      paymentInfo = await fetchShopInBitPaymentInfo(
+        ref,
+        widget.model.apiTicketId,
+      );
+    } catch (e) {
+      debugPrint("submitAddress threw: $e");
+    } finally {
+      if (mounted) setState(() => _submitting = false);
     }
 
     if (!mounted) return;
 
+    if (paymentInfo == null || paymentInfo.paymentLinks.isEmpty) {
+      // No live invoice; don't open a payment view with empty addresses.
+      await _showPaymentLoadError(
+        "We couldn't load the payment details for this order. "
+        "Please try again in a moment.",
+      );
+      return;
+    }
+
     unawaited(
       Navigator.of(context).pushNamed(
         ShopInBitPaymentView.routeName,
@@ -266,6 +281,19 @@ class _ShopInBitShippingViewState extends ConsumerState<ShopInBitShippingView> {
     );
   }
 
+  Future<void> _showPaymentLoadError(String message) async {
+    await showDialog<void>(
+      context: context,
+      useRootNavigator: Util.isDesktop,
+      builder: (context) => StackOkDialog(
+        title: "Couldn't load payment details",
+        maxWidth: Util.isDesktop ? 500 : null,
+        message: message,
+        desktopPopRootNavigator: Util.isDesktop,
+      ),
+    );
+  }
+
   // Read-only display of the locked delivery country: it was fixed when the
   // offer was priced and can't change here.
   Widget _buildLockedCountryField() {
diff --git a/lib/route_generator.dart b/lib/route_generator.dart
index df03fd5..9c98d6f 100644
--- a/lib/route_generator.dart
+++ b/lib/route_generator.dart
@@ -1259,12 +1259,12 @@ class RouteGenerator {
         return _routeError("${settings.name} invalid args: ${args.toString()}");
 
       case ShopInBitPaymentView.routeName:
-        if (args is (ShopInBitOrderModel, PaymentInfo?)) {
+        if (args is (ShopInBitOrderModel, PaymentInfo)) {
           return getRoute(
             shouldUseMaterialRoute: useMaterialPageRoute,
             builder: (_) => ShopInBitPaymentView(
               model: args.$1,
-              initialPaymentInfo: args.$2,
+              paymentInfo: args.$2,
             ),
             settings: RouteSettings(name: settings.name),
           );
diff --git a/lib/widgets/dialogs/nested_navigator_dialog/nested_navigator_dialog_route_generator.dart b/lib/widgets/dialogs/nested_navigator_dialog/nested_navigator_dialog_route_generator.dart
index e5561b4..f97e6f2 100644
--- a/lib/widgets/dialogs/nested_navigator_dialog/nested_navigator_dialog_route_generator.dart
+++ b/lib/widgets/dialogs/nested_navigator_dialog/nested_navigator_dialog_route_generator.dart
@@ -196,11 +196,11 @@ abstract final class NestedNavigatorDialogRouteGenerator {
         );
 
       case ShopInBitPaymentView.routeName:
-        if (args is (ShopInBitOrderModel, PaymentInfo?)) {
+        if (args is (ShopInBitOrderModel, PaymentInfo)) {
           return getRoute(
             builder: (_) => ShopInBitPaymentView(
               model: args.$1,
-              initialPaymentInfo: args.$2,
+              paymentInfo: args.$2,
             ),
             settings: RouteSettings(name: settings.name),
           );
@@ -208,7 +208,7 @@ abstract final class NestedNavigatorDialogRouteGenerator {
         return _routeError(
           "${settings.name} invalid args\n"
           "Got ${args.runtimeType}\n"
-          "Expected (ShopInBitOrderModel, PaymentInfo?)",
+          "Expected (ShopInBitOrderModel, PaymentInfo)",
         );
 
       case CakePayVendorsView.routeName: