Allow Lightning invoice reuse and re-payment from the dashboard.

Store LNbits invoice data on payments, add an invoice endpoint that reuses valid invoices or regenerates expired ones, and wire the booking payment page to fetch and display invoices via a shared watcher hook.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/lib/api/tickets.ts

@@ -6,6 +6,7 @@ import type {
   TicketValidationResult,
   TicketSearchResult,
   LiveSearchResult,
+  LightningInvoice,
 } from './types';
 
 export const ticketsApi = {
@@ -137,6 +138,14 @@ export const ticketsApi = {
       `/api/lnbits/status/${ticketId}`
     ),
 
+  // Get a Lightning invoice to pay/re-pay a ticket - reuses the stored invoice
+  // if it's still valid, otherwise generates a fresh one.
+  getLightningInvoice: (ticketId: string) =>
+    fetchApi<{ invoice?: LightningInvoice; reused?: boolean; alreadyPaid?: boolean }>(
+      `/api/lnbits/invoice/${ticketId}`,
+      { method: 'POST' }
+    ),
+
   // Get PDF download URL (returns the URL, not the PDF itself)
   getPdfUrl: (id: string) => `${API_BASE}/api/tickets/${id}/pdf`,
 };

frontend/src/lib/api/types.ts

@@ -25,6 +25,15 @@ export interface Event {
   updatedAt: string;
 }
 
+export interface LightningInvoice {
+  paymentHash: string;
+  paymentRequest: string; // BOLT11 invoice
+  amount: number; // Amount in satoshis
+  fiatAmount?: number; // Original fiat amount
+  fiatCurrency?: string; // Original fiat currency
+  expiresAt?: string;
+}
+
 export interface Ticket {
   id: string;
   bookingId?: string; // Groups multiple tickets from same booking