feat(bookings): implement booking system and confirmation flow

Add database tables and repository for managing bookings
Create API endpoints for booking submission and capacity management
Update landing page to persist bookings before WhatsApp redirection

server/api/public/bookings/[token]/confirm.post.ts

@@ -0,0 +1,35 @@
+import { confirmBookingByConfirmationToken, getBookingByConfirmationToken, getBookingInventorySummary } from '../../../../utils/booking-repository'
+import { getRequiredRouteParam, httpError } from '../../../../utils/http'
+
+export default defineEventHandler(async (event) => {
+  const token = getRequiredRouteParam(event, 'token', 'Confirmation token')
+  const existingBooking = await getBookingByConfirmationToken(token)
+
+  if (!existingBooking) {
+    httpError(404, 'Booking not found')
+  }
+
+  if (existingBooking.status === 'confirmed') {
+    return {
+      booking: existingBooking,
+      alreadyConfirmed: true
+    }
+  }
+
+  const summary = await getBookingInventorySummary()
+
+  if (summary.leftCapacitySeats !== null && existingBooking.seatCount > summary.leftCapacitySeats) {
+    httpError(409, 'Not enough capacity left to confirm this booking')
+  }
+
+  const booking = await confirmBookingByConfirmationToken(token)
+
+  if (!booking) {
+    httpError(404, 'Booking not found')
+  }
+
+  return {
+    booking,
+    alreadyConfirmed: false
+  }
+})