fix: final review wave (reminder-400, contact-400, soon-30, cron-claim, edge-session)

app/vouchers/new/page.tsx

@@ -101,6 +101,7 @@ export default function NewVoucherPage() {
             placeholder="30,6,1"
             className="mt-1 w-full rounded border px-3 py-2"
           />
+            {errors.includes("reminderDays") && <p className="mt-1 text-sm text-red-600">Ungültig: reminderDays</p>}
         </div>
         <section id="kontakte">
           <h2 className="text-sm font-medium">Empfänger</h2>