feat: add customer email functionality for booking confirmations

- Implemented email confirmation for admin and public bookings.
- Added customerEmail field to booking schemas and services.
- Created email templates for booking confirmation, cancellation, and no-show notifications.
- Updated booking handlers to send emails upon booking creation and status updates.
- Enhanced frontend forms to capture customer email during booking creation.

apps/frontend/src/features/booking/booking-provider.tsx

@@ -41,6 +41,7 @@ interface CreateManualBookingPayload {
   startTime: string;
   customerName: string;
   customerPhone: string;
+  customerEmail?: string;
 }
 
 interface BookingContextValue {
@@ -315,6 +316,7 @@ export function BookingProvider({ children, complex }: BookingProviderProps) {
         startTime: payload.startTime,
         customerName: payload.customerName,
         customerPhone: payload.customerPhone,
+        customerEmail: payload.customerEmail || undefined,
       }),
     onSuccess: async () => {
       await queryClient.invalidateQueries({ queryKey: ['admin-bookings', complex.id] });