feat: add payment management improvements and reminder emails

- Add option to approve/reject payments without sending notification emails
  (checkbox in review popup, default enabled)
- Add payment reminder email template and send functionality
- Track when reminder emails are sent (reminderSentAt field)
- Display reminder sent timestamp in payment review popup
- Make payment review popup scrollable for better UX
- Add payment-reminder template to email system (available in admin emails)

frontend/src/app/(public)/book/[eventId]/page.tsx

@@ -473,8 +473,8 @@ export default function BookingPage() {
     paymentMethods.push({
       id: 'tpago',
       icon: CreditCardIcon,
-      label: locale === 'es' ? 'TPago / Tarjeta Internacional' : 'TPago / International Card',
-      description: locale === 'es' ? 'Paga con tarjeta de crédito o débito' : 'Pay with credit or debit card',
+      label: locale === 'es' ? 'TPago / Tarjetas de Crédito' : 'TPago / Credit Cards',
+      description: locale === 'es' ? 'Pagá con tarjetas de crédito locales o internacionales' : 'Pay with local or international credit cards',
       badge: locale === 'es' ? 'Manual' : 'Manual',
     });
   }
@@ -483,8 +483,8 @@ export default function BookingPage() {
     paymentMethods.push({
       id: 'bank_transfer',
       icon: BuildingLibraryIcon,
-      label: locale === 'es' ? 'Transferencia Bancaria' : 'Bank Transfer',
-      description: locale === 'es' ? 'Transferencia bancaria local' : 'Local bank transfer',
+      label: locale === 'es' ? 'Transferencia Bancaria Local' : 'Local Bank Transfer',
+      description: locale === 'es' ? 'Pago por transferencia bancaria en Paraguay' : 'Pay via Paraguayan bank transfer',
       badge: locale === 'es' ? 'Manual' : 'Manual',
     });
   }

frontend/src/app/admin/payments/page.tsx

@@ -19,6 +19,7 @@ import {
   BanknotesIcon,
   BuildingLibraryIcon,
   CreditCardIcon,
+  EnvelopeIcon,
 } from '@heroicons/react/24/outline';
 import toast from 'react-hot-toast';
 
@@ -38,6 +39,8 @@ export default function AdminPaymentsPage() {
   const [selectedPayment, setSelectedPayment] = useState<PaymentWithDetails | null>(null);
   const [noteText, setNoteText] = useState('');
   const [processing, setProcessing] = useState(false);
+  const [sendEmail, setSendEmail] = useState(true);
+  const [sendingReminder, setSendingReminder] = useState(false);
   
   // Export state
   const [showExportModal, setShowExportModal] = useState(false);
@@ -77,10 +80,11 @@ export default function AdminPaymentsPage() {
   const handleApprove = async (payment: PaymentWithDetails) => {
     setProcessing(true);
     try {
-      await paymentsApi.approve(payment.id, noteText);
+      await paymentsApi.approve(payment.id, noteText, sendEmail);
       toast.success(locale === 'es' ? 'Pago aprobado' : 'Payment approved');
       setSelectedPayment(null);
       setNoteText('');
+      setSendEmail(true);
       loadData();
     } catch (error: any) {
       toast.error(error.message || 'Failed to approve payment');
@@ -92,10 +96,11 @@ export default function AdminPaymentsPage() {
   const handleReject = async (payment: PaymentWithDetails) => {
     setProcessing(true);
     try {
-      await paymentsApi.reject(payment.id, noteText);
+      await paymentsApi.reject(payment.id, noteText, sendEmail);
       toast.success(locale === 'es' ? 'Pago rechazado' : 'Payment rejected');
       setSelectedPayment(null);
       setNoteText('');
+      setSendEmail(true);
       loadData();
     } catch (error: any) {
       toast.error(error.message || 'Failed to reject payment');
@@ -104,6 +109,24 @@ export default function AdminPaymentsPage() {
     }
   };
 
+  const handleSendReminder = async (payment: PaymentWithDetails) => {
+    setSendingReminder(true);
+    try {
+      const result = await paymentsApi.sendReminder(payment.id);
+      toast.success(locale === 'es' ? 'Recordatorio enviado' : 'Reminder sent');
+      // Update the selected payment with the new reminderSentAt timestamp
+      if (result.reminderSentAt) {
+        setSelectedPayment({ ...payment, reminderSentAt: result.reminderSentAt });
+      }
+      // Also refresh the data to update the lists
+      loadData();
+    } catch (error: any) {
+      toast.error(error.message || 'Failed to send reminder');
+    } finally {
+      setSendingReminder(false);
+    }
+  };
+
   const handleConfirmPayment = async (id: string) => {
     try {
       await paymentsApi.approve(id);
@@ -317,7 +340,7 @@ export default function AdminPaymentsPage() {
         const modalBookingInfo = getBookingInfo(selectedPayment);
         return (
         <div className="fixed inset-0 bg-black/50 z-50 flex items-center justify-center p-4">
-          <Card className="w-full max-w-lg p-6">
+          <Card className="w-full max-w-lg max-h-[90vh] overflow-y-auto p-6">
             <h2 className="text-xl font-bold mb-4">
               {locale === 'es' ? 'Verificar Pago' : 'Verify Payment'}
             </h2>
@@ -374,6 +397,13 @@ export default function AdminPaymentsPage() {
                 </div>
               )}
               
+              {selectedPayment.reminderSentAt && (
+                <div className="flex items-center gap-2 text-sm text-amber-600">
+                  <EnvelopeIcon className="w-4 h-4" />
+                  {locale === 'es' ? 'Recordatorio enviado:' : 'Reminder sent:'} {formatDate(selectedPayment.reminderSentAt)}
+                </div>
+              )}
+              
               {selectedPayment.payerName && (
                 <div className="bg-amber-50 border border-amber-200 rounded-lg p-3">
                   <p className="text-sm text-amber-800 font-medium">
@@ -395,6 +425,19 @@ export default function AdminPaymentsPage() {
                   placeholder={locale === 'es' ? 'Agregar nota...' : 'Add a note...'}
                 />
               </div>
+              
+              <div className="flex items-center gap-2">
+                <input
+                  type="checkbox"
+                  id="sendEmail"
+                  checked={sendEmail}
+                  onChange={(e) => setSendEmail(e.target.checked)}
+                  className="w-4 h-4 text-primary-yellow border-gray-300 rounded focus:ring-primary-yellow"
+                />
+                <label htmlFor="sendEmail" className="text-sm text-gray-700">
+                  {locale === 'es' ? 'Enviar email de notificación' : 'Send notification email'}
+                </label>
+              </div>
             </div>
             
             <div className="flex gap-3">
@@ -417,8 +460,20 @@ export default function AdminPaymentsPage() {
               </Button>
             </div>
             
+            <div className="pt-2 border-t">
+              <Button
+                variant="outline"
+                onClick={() => handleSendReminder(selectedPayment)}
+                isLoading={sendingReminder}
+                className="w-full"
+              >
+                <EnvelopeIcon className="w-5 h-5 mr-2" />
+                {locale === 'es' ? 'Enviar recordatorio de pago' : 'Send payment reminder'}
+              </Button>
+            </div>
+            
             <button
-              onClick={() => { setSelectedPayment(null); setNoteText(''); }}
+              onClick={() => { setSelectedPayment(null); setNoteText(''); setSendEmail(true); }}
               className="w-full mt-3 py-2 text-sm text-gray-500 hover:text-gray-700"
             >
               {locale === 'es' ? 'Cancelar' : 'Cancel'}