Fix groupPaymentMethodsForCheckout ignoring sortOrder

Hardcoded manual rows first, then the combined stripe option — so
"Online-Zahlung" (sortOrder 0) showed after "Überweisung (Vorkasse)"
(sortOrder 1) in checkout, contradicting the admin's own ordering.
Now preserves the fetch's sortOrder-sorted order, splicing the combined
entry in at the position of the first stripe row encountered.

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

app/lib/payload.ts

@@ -638,9 +638,8 @@ export type CheckoutPaymentOption = PaymentMethod & { hint?: string };
 // `manual` rows (Überweisung) pass through unchanged — one real gateway
 // there, one option, nothing to collapse.
 export function groupPaymentMethodsForCheckout(methods: PaymentMethod[]): CheckoutPaymentOption[] {
-  const manual = methods.filter((m) => m.provider !== "stripe");
   const stripeMethods = methods.filter((m) => m.provider === "stripe");
-  if (stripeMethods.length === 0) return manual;
+  if (stripeMethods.length === 0) return methods;
 
   const combinedIcons = Array.from(new Set(stripeMethods.flatMap((m) => m.icons)));
   const online: CheckoutPaymentOption = {
@@ -650,7 +649,27 @@ export function groupPaymentMethodsForCheckout(methods: PaymentMethod[]): Checko
     provider: "stripe",
     hint: "Kreditkarte, PayPal & weitere Methoden — die genaue Zahlungsart wählst du im nächsten Schritt.",
   };
-  return [...manual, online];
+
+  // Preserve `methods`' own order (already sortOrder-sorted by the fetch)
+  // instead of hardcoding manual-first — a real bug: "Online-Zahlung" had
+  // a lower sortOrder than "Überweisung (Vorkasse)" in the admin, but
+  // this function always put manual rows first regardless, so the
+  // checkout showed them in the wrong order. Splice the combined entry in
+  // at the position of the *first* stripe row encountered, drop any
+  // further stripe rows (already folded into `online`).
+  const result: CheckoutPaymentOption[] = [];
+  let onlineInserted = false;
+  for (const m of methods) {
+    if (m.provider === "stripe") {
+      if (!onlineInserted) {
+        result.push(online);
+        onlineInserted = true;
+      }
+      continue;
+    }
+    result.push(m);
+  }
+  return result;
 }
 
 export type WerkzeugeCard = {