feat: implement public booking cancellation feature

- Added cancelPublicBooking handler to manage booking cancellations.
- Updated public booking service to include cancellation logic.
- Created cancelPublicBooking schema for input validation.
- Modified public booking confirmation page to allow users to cancel their bookings.
- Enhanced email service to send cancellation confirmation emails.
- Made customerEmail field required in booking schemas and updated related components.
- Updated API client to support cancellation requests.
- Added migration to enforce non-nullable customer_email fields in the database.

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

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