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>

backend/src/db/schema.ts

@@ -121,6 +121,9 @@ export const sqlitePayments = sqliteTable('payments', {
   currency: text('currency').notNull().default('PYG'),
   status: text('status', { enum: ['pending', 'pending_approval', 'paid', 'refunded', 'failed', 'cancelled', 'on_hold'] }).notNull().default('pending'),
   reference: text('reference'),
+  lnbitsInvoice: text('lnbits_invoice'), // BOLT11 string, stored so an unpaid invoice can be redisplayed without a new LNbits call
+  lnbitsExpiresAt: text('lnbits_expires_at'), // When lnbitsInvoice expires
+  lnbitsAmountSats: integer('lnbits_amount_sats'), // Sats amount for display (from LNbits' fiat conversion)
   userMarkedPaidAt: text('user_marked_paid_at'), // When user clicked "I Have Paid"
   payerName: text('payer_name'), // Name of payer if different from attendee
   paidAt: text('paid_at'),
@@ -476,6 +479,9 @@ export const pgPayments = pgTable('payments', {
   currency: varchar('currency', { length: 10 }).notNull().default('PYG'),
   status: varchar('status', { length: 20 }).notNull().default('pending'),
   reference: varchar('reference', { length: 255 }),
+  lnbitsInvoice: pgText('lnbits_invoice'), // BOLT11 string, stored so an unpaid invoice can be redisplayed without a new LNbits call
+  lnbitsExpiresAt: timestamp('lnbits_expires_at'), // When lnbitsInvoice expires
+  lnbitsAmountSats: pgInteger('lnbits_amount_sats'), // Sats amount for display (from LNbits' fiat conversion)
   userMarkedPaidAt: timestamp('user_marked_paid_at'),
   payerName: varchar('payer_name', { length: 255 }), // Name of payer if different from attendee
   paidAt: timestamp('paid_at'),