Fix Service Booking Creation Is Not Synchronized Between Processes

Changes:

- Updated ServiceManagementService::purchaseService() to persist service
  bookings immediately after creation using m_dataStore.saveServiceBookings().
- Updated ServiceManagementService::purchaseComboPackage() to persist
  combo package bookings immediately after creation using
  m_dataStore.saveServiceBookings().
- Changed DataStore::getJobCards() to use a reference for tracked bookings
  to ensure consistent linkage and prevent overwriting.

Fixes #2074

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/datastores/DataStore.cpp

@@ -415,7 +415,7 @@ util::Map<std::string, TrackedRecord<JobCard>>& DataStore::getJobCards()
         {
             throw std::runtime_error("Invalid booking ID: " + bookingId);
         }
-        auto trackedBooking = serviceBookings.getValueAt(bookingIndex);
+        auto& trackedBooking = serviceBookings.getValueAt(bookingIndex);
         jobCard->setBooking(trackedBooking.data);
         const std::string& serviceId = jobCard->getServiceId();
         int serviceIndex = services.find(serviceId);

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/ServiceManagementService.cpp

@@ -72,6 +72,7 @@ void ServiceManagementService::purchaseService(const util::Vector<std::string>&
     std::string title = "Service Booking succeeded";
     std::string message = "Your service booking has been successfully placed with ID " + serviceBooking->getId();
     sendNotification(authenticatedUser, title, message);
+    m_dataStore.saveServiceBookings();
 }
 
 /*
@@ -112,6 +113,7 @@ void ServiceManagementService::purchaseComboPackage(const std::string& comboPack
     std::string title = "Combo Package Service Booking succeeded";
     std::string message = "Your service booking for the combo package has been successfully placed with ID " + serviceBooking->getId();
     sendNotification(authenticatedUser, title, message);
+    m_dataStore.saveServiceBookings();
 }
 
 util::Map<std::string, User*> ServiceManagementService::m_observers{};