Update Postman collection

backend/src/main/java/com/petshop/backend/service/AppointmentService.java

@@ -218,7 +218,6 @@ public class AppointmentService {
         List<Long> employeeIds = assignableEmployees.stream().map(Employee::getEmployeeId).collect(Collectors.toList());
         List<Appointment> allAppointments = appointmentRepository.findByEmployeeEmployeeIdInAndAppointmentDate(employeeIds, date);
         
-        // Group by employee for faster lookup in the loop
         java.util.Map<Long, List<Appointment>> appointmentsByEmployee = allAppointments.stream()
                 .collect(Collectors.groupingBy(a -> a.getEmployee().getEmployeeId()));
 
@@ -350,7 +349,6 @@ public class AppointmentService {
                 .isPresent();
     }
 
-    //------------------------------------
     private void validateAvailability(Employee employee, com.petshop.backend.entity.Service service, LocalDate date, LocalTime time, Long appointmentIdToIgnore) {
         List<Appointment> existingAppointments = appointmentRepository
                 .findByEmployeeEmployeeIdAndAppointmentDate(employee.getEmployeeId(), date);
@@ -359,8 +357,6 @@ public class AppointmentService {
         }
     }
 
-    //------------------------------------------------
-
     private boolean isSlotAvailable(List<Appointment> existingAppointments, com.petshop.backend.entity.Service requestedService, LocalTime requestedStart, Long appointmentIdToIgnore) {
         LocalTime requestedEnd = requestedStart.plusMinutes(requestedService.getServiceDuration());
         for (Appointment existingAppointment : existingAppointments) {