Profile: Rechnungsadresse is always a street address, no Packstation toggle

Matches /checkout's own billing card exactly (an invoice needs a real
postal address) — the profile form previously offered a Lieferart/
Packstation choice for what's actually always used as the billing
address, inconsistent now that a separate "Lieferadresse" section exists.

app/api/account/profile/route.ts

@@ -16,10 +16,7 @@ export async function PATCH(request: Request) {
   const {
     firstName,
     lastName,
-    deliveryMethod,
     street,
-    packstationNumber,
-    postNumber,
     zip,
     city,
     country,
@@ -44,7 +41,8 @@ export async function PATCH(request: Request) {
     !firstName ||
     typeof lastName !== "string" ||
     !lastName ||
-    (deliveryMethod !== "address" && deliveryMethod !== "packstation") ||
+    typeof street !== "string" ||
+    !street ||
     typeof zip !== "string" ||
     !zip ||
     typeof city !== "string" ||
@@ -54,12 +52,6 @@ export async function PATCH(request: Request) {
   ) {
     return NextResponse.json({ ok: false, reason: "Bitte alle Pflichtfelder ausfüllen." }, { status: 400 });
   }
-  if (deliveryMethod === "address" && !street) {
-    return NextResponse.json({ ok: false, reason: "Bitte Straße und Hausnummer angeben." }, { status: 400 });
-  }
-  if (deliveryMethod === "packstation" && (!packstationNumber || !postNumber)) {
-    return NextResponse.json({ ok: false, reason: "Bitte Packstation- und Postnummer angeben." }, { status: 400 });
-  }
   // Both independently optional (see Customers.ts's own comment) — only
   // format-checked when actually provided, same as the backend field itself.
   const normalizedVatId = typeof vatId === "string" && vatId ? normalizeVatId(vatId) : undefined;
@@ -97,10 +89,8 @@ export async function PATCH(request: Request) {
   const result = await updateCustomerProfile(session.token, session.customer.id, {
     firstName,
     lastName,
-    deliveryMethod,
+    deliveryMethod: "address",
     street,
-    packstationNumber,
-    postNumber,
     zip,
     city,
     country,