fix(invoice): unify customer-facing remittance reference with the printed invoice number

Two related fixes around the order/invoice number:

1) The thank-you page and the customer-account order page were showing
   the bare Shopify order name (e.g. '#1034') as the payment reference,
   while the PDF (and its GiroCode QR) used the canonical invoice
   number (e.g. 'RE-1034'). Banks treat each unique reference as a
   separate payment, and several reject the '#' character outright \u2014
   so customers who pasted the thank-you reference into their banking
   app ended up with a payment the shop couldn't reconcile.

   New shared helper resolveOrderRemittance() (services/invoice/
   remittance.server.ts) returns the single source of truth for the
   reference: latest non-cancelled Invoice row for the order, falling
   back to '${prefix}${orderNumber}' when no PDF has been generated yet.
   Both /api/public/payment-info and /api/public/girocode.png now route
   through it, so the thank-you page, the customer-account page and the
   GiroCode QR are guaranteed to match the PDF byte-for-byte.

2) Drop the redundant '\u00b7 Bestellnummer: #1004' suffix from the PDF
   title when the invoice number's trailing digits already match the
   Shopify order name (default 'order_number' numbering mode). In that
   mode the two strings carry identical numeric content and the suffix
   only adds noise; sequential mode (RE-7 vs #1004) keeps the suffix.

- New smoke assertion verifies the suppression triggers on
  invoiceNumber='RE-1004' + orderName='#1004' and that the invoice
  number itself is still shown.
- Both endpoints now also query 'Order.number' (already covered by
  read_orders) so the fallback path can build the prefix+order-number
  string without requiring the Invoice row.

app/routes/api.public.girocode[.png].tsx

@@ -3,6 +3,7 @@ import { unauthenticated } from "../shopify.server";
 import db from "../db.server";
 import { buildGiroCodePngBuffer } from "../services/invoice/girocode";
 import { verifyGiroCodeUrl } from "../services/invoice/signedUrl";
+import { resolveOrderRemittance } from "../services/invoice/remittance.server";
 
 /**
  * Public PNG endpoint that returns the GiroCode QR image bytes for an order.
@@ -36,6 +37,7 @@ export const loader = async ({ request }: LoaderFunctionArgs) => {
     query GiroCodeOrderInfo($id: ID!) {
       order(id: $id) {
         name
+        number
         currencyCode
         totalPriceSet { shopMoney { amount } }
         totalOutstandingSet { shopMoney { amount } }
@@ -47,6 +49,7 @@ export const loader = async ({ request }: LoaderFunctionArgs) => {
     data?: {
       order?: {
         name?: string;
+        number?: number | null;
         currencyCode?: string;
         totalPriceSet?: { shopMoney: { amount: string } };
         totalOutstandingSet?: { shopMoney: { amount: string } };
@@ -61,7 +64,15 @@ export const loader = async ({ request }: LoaderFunctionArgs) => {
   const total = parseFloat(o.totalPriceSet?.shopMoney.amount ?? "0");
   const outstanding = parseFloat(o.totalOutstandingSet?.shopMoney.amount ?? "0");
   const amount = outstanding > 0 ? outstanding : total;
-  const remittance = o.name ?? numericId;
+  // Use the canonical invoice number printed on the PDF — keeping the QR
+  // and the customer-facing thank-you/account page in lockstep so the
+  // bank treats both as one and the same payment.
+  const remittance = await resolveOrderRemittance({
+    shopDomain: shop,
+    orderGid,
+    orderNumber: typeof o.number === "number" ? o.number : null,
+    settings,
+  });
 
   const png = await buildGiroCodePngBuffer({
     beneficiaryName: [settings.companyName, settings.legalForm].filter(Boolean).join(" "),