Hide failed-payment order attempts from the customer's own order history

A cancelled order with no invoiceNumber is a Stripe payment that never
succeeded (failed or timed out before ever reaching received/invoiced),
not a real cancellation of something that actually happened — from the
customer's point of view it was never really an order. Filtered out of
getCustomerOrders/getCustomerOrderDetail by default; the row stays in
Payload for admin/audit purposes (shown there as "Zahlung
fehlgeschlagen", see backend).

getCustomerOrderDetail's filter is opt-in via a new optional parameter,
not the default — /api/checkout/status/route.ts's post-payment polling
needs to keep seeing exactly this order to show the "Zahlung
fehlgeschlagen, bitte erneut versuchen" retry state. The GDPR export
route also opts out for the same reason a legal completeness export
can't silently drop rows.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/konto/bestellungen/[orderNumber]/page.tsx

@@ -33,7 +33,7 @@ export default async function KontoBestellungDetailPage({ params }: { params: Pr
   const session = await getSessionCustomer();
   if (!session) redirect("/konto/login");
 
-  const order = await getCustomerOrderDetail(session.token, session.customer.id, decodeURIComponent(orderNumber));
+  const order = await getCustomerOrderDetail(session.token, session.customer.id, decodeURIComponent(orderNumber), true);
   if (!order) notFound();
 
   const address =