Consolidate Kreditkarte/PayPal into one "Online-Zahlung" checkout option

Both already route through the same Stripe PaymentIntent
(automatic_payment_methods: enabled — Stripe's own recommended Payment
Element pattern, letting Stripe itself decide which eligible method to
show). Pre-selecting one of two identical-behind-the-scenes rows before
the payment step was redundant friction, not a real choice. Collapses
them into one option with a hint text explaining the actual instrument
is picked on the next screen; Überweisung is unaffected.

Also refines paymentMethodTitle from a neutral "Online-Zahlung"
placeholder (snapshotted at order-creation time, before the customer has
picked an instrument) to the real one Stripe reports, once payment
confirms — carried through to both the stored order and the
sessionStorage snapshot shown on /bestellbestaetigung.

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

app/api/checkout/route.ts

@@ -343,7 +343,15 @@ export async function POST(request: Request) {
     subtotal: finalSubtotal,
     shippingCost: finalShippingCost,
     shippingMethodTitle: shippingMethod.title,
-    paymentMethodTitle: paymentMethod.title,
+    // The checkout UI collapses Kreditkarte/PayPal into one "Online-
+    // Zahlung" pre-selection (see groupPaymentMethodsForCheckout) — the
+    // customer hasn't actually chosen an instrument yet at this point,
+    // Stripe's Payment Element does that next. Snapshotting the specific
+    // resolved row's title here would just record whichever row happened
+    // to be the group's representative id, not what was really picked.
+    // The webhook route refines this to the real instrument
+    // ("Kreditkarte"/"PayPal") once Stripe reports it, via confirm-payment.
+    paymentMethodTitle: requiresPayment ? "Online-Zahlung" : paymentMethod.title,
     discountCode: body.discountCode || null,
     discountAmount,
     total,
@@ -476,7 +484,7 @@ export async function POST(request: Request) {
         }
       : {}),
     shippingCost: finalShippingCost,
-    paymentMethodTitle: paymentMethod.title,
+    paymentMethodTitle: requiresPayment ? "Online-Zahlung" : paymentMethod.title,
     discountCode: body.discountCode || null,
     discountAmount,
     vatExempt,

app/api/checkout/status/route.ts

@@ -17,5 +17,15 @@ export async function GET(request: Request) {
   const order = await getCustomerOrderDetail(session.token, session.customer.id, orderNumber);
   if (!order) return NextResponse.json({ ok: false, reason: "Bestellung nicht gefunden." }, { status: 404 });
 
-  return NextResponse.json({ ok: true, status: order.status, paymentStatus: order.paymentStatus });
+  return NextResponse.json({
+    ok: true,
+    status: order.status,
+    paymentStatus: order.paymentStatus,
+    // Refined from the checkout-time "Online-Zahlung" placeholder to the
+    // actual instrument (Kreditkarte/PayPal) once confirm-payment sets it
+    // — see resolveStripePaymentMethodLabel's own comment. Returned here
+    // so VerarbeitungContent can patch the pending sessionStorage snapshot
+    // before promoting it, so /bestellbestaetigung shows the real one.
+    paymentMethodTitle: order.paymentMethodTitle,
+  });
 }