Make templates editable for existing orders and add {date:iso}/{date:at} formats

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/frontend/src/components/orders/ReadOnlyOrderOverviewCard.tsx

@@ -62,6 +62,7 @@ export default function ReadOnlyOrderOverviewCard({
   notifications,
   allowExport = false,
   onSavePayment,
+  onSaveTemplates,
   extraTabs = [],
   activeTabKey,
   onTabChange,
@@ -80,6 +81,8 @@ export default function ReadOnlyOrderOverviewCard({
   allowExport?: boolean;
   /** Makes the payment tab editable (order admin only); without it the tab is read-only. */
   onSavePayment?: (payment: OrderPaymentDetails) => Promise<void>;
+  /** Makes the templates tab editable (order admin only); without it the tab is read-only. */
+  onSaveTemplates?: (templates: OrderTemplates) => Promise<void>;
   extraTabs?: NonNullable<TabsProps["items"]>;
   activeTabKey?: string;
   onTabChange?: (key: string) => void;
@@ -207,7 +210,8 @@ export default function ReadOnlyOrderOverviewCard({
                       templates={templates}
                       config={currentConfig}
                       previewContext={templatePreviewContext}
-                      readOnly
+                      readOnly={!onSaveTemplates}
+                      onSave={onSaveTemplates}
                     />
                   ),
                 },

src/frontend/src/lib/orderTemplating.ts

@@ -115,7 +115,9 @@ export const BODY_PLACEHOLDERS = [
   { key: "{creator}", description: "Order creator email" },
   { key: "{participants}", description: "Participant emails (comma separated)" },
   { key: "{link}", description: "Participant page link" },
-  { key: "{date}", description: "Today's date" },
+  { key: "{date}", description: "Today's date in the browser's culture" },
+  { key: "{date:iso}", description: "Today's date as ISO 8601, e.g. 2026-11-04" },
+  { key: "{date:at}", description: "Today's date in Austrian format, e.g. 04.11.2026" },
   { key: "{tally:Label}", description: "Count per item of a category, e.g. \"3x Fries\"" },
 ];
 
@@ -240,6 +242,23 @@ function decodeSeparator(separator: string): string {
   return separator.replace(/\\n/g, "\n").replace(/\\t/g, "\t");
 }
 
+function pad2(value: number): string {
+  return String(value).padStart(2, "0");
+}
+
+// Culture-independent formats; without (or with an unknown) format the current culture is used.
+function formatDate(date: Date, format: string | undefined): string {
+  const year = date.getFullYear();
+  const month = pad2(date.getMonth() + 1);
+  const day = pad2(date.getDate());
+
+  switch (format?.trim().toLowerCase()) {
+    case "iso": return `${year}-${month}-${day}`;
+    case "at": return `${day}.${month}.${year}`;
+    default: return date.toLocaleDateString();
+  }
+}
+
 function formatAmount(value: number | null): string {
   return value === null ? "" : `€${value.toFixed(2)}`;
 }
@@ -578,7 +597,7 @@ export function renderTemplateText(
       case "creator": return context.creatorEmail || "";
       case "participants": return getParticipantEmails(context).join(", ");
       case "link": return context.participantUrl;
-      case "date": return new Date().toLocaleDateString();
+      case "date": return formatDate(new Date(), arg);
       case "tally": return arg ? renderTally(arg, context) : undefined;
       default: return undefined;
     }

src/frontend/src/views/AdminView.tsx

@@ -233,6 +233,18 @@ export default function AdminView({ orderId }: { orderId: string }) {
     }
   };
 
+  const saveTemplates = async (templates: OrderTemplates) => {
+    try {
+      const saved = await apiService.orders.updateTemplates(orderId, templates);
+      setData((previous: AdminViewData | null) =>
+        previous ? { ...previous, templates: normalizeOrderTemplates(saved) } : previous,
+      );
+      message.success("Templates saved");
+    } catch (error: any) {
+      message.error(error.message);
+    }
+  };
+
   const saveNotifications = async (notifications: OrderNotifications) => {
     try {
       const saved = await apiService.orders.updateNotifications(orderId, notifications);
@@ -410,6 +422,7 @@ export default function AdminView({ orderId }: { orderId: string }) {
         notifications={data?.notifications}
         allowExport
         onSavePayment={savePayment}
+        onSaveTemplates={saveTemplates}
         extraTabs={[
           {
             key: "notifications",