Fix Completing a Job Throws an Exception

Changes:

- Refactored ServiceManagementService::updateJobStatus() to use tracked
  job card references instead of raw pointers, ensuring consistent state
  updates.
- Added proper null checks and error handling for current job retrieval
  to prevent unexpected termination.
- Updated logic to mark tracked job records as MODIFIED when status
  transitions occur (STARTED → IN_PROGRESS, IN_PROGRESS → COMPLETED).
- Simplified control flow and indentation for better readability and
  maintainability.

Fixes #2076

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/datastores/DataStore.h

@@ -220,6 +220,11 @@ void DataStore::refreshCache(util::Map<std::string, TrackedRecord<TObject>>& cac
         if (oldIndex != -1)
         {
             TrackedRecord<TObject>& oldRecord = oldCache.getValueAt(oldIndex);
+            if (oldRecord.state == RecordState::MODIFIED)
+            {
+                cache.insert(id, oldRecord);
+                continue;
+            }
             *oldRecord.data = *refreshedRecord.data;
             oldRecord.slotIndex = refreshedRecord.slotIndex;
             oldRecord.state = refreshedRecord.state;

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

@@ -883,7 +883,6 @@ void ServiceManagementService::updateJobStatus(const std::string& jobID)
     AuthenticationManagementService authenticationManagementService;
     PaymentManagementService paymentManagementService;
     bool jobStatusUpdated = false, serviceBookingCompleted;
-	JobCard* currentJob;
     User* currentTechnician = authenticationManagementService.getAuthenticatedUser();
     if (currentTechnician == nullptr)
     {
@@ -903,7 +902,8 @@ void ServiceManagementService::updateJobStatus(const std::string& jobID)
         {
             throw std::runtime_error("Unable to fetch current job.");
         }
-		currentJob = currentAssignedJobs.getValueAt(currentAssignedJobs.find(jobID));
+        auto& trackedCurrentJob = trackedJobCards.getValueAt(jobIndex);
+        JobCard* currentJob = trackedCurrentJob.data;
         if (currentJob == nullptr)
         {
             throw std::runtime_error("Unable to fetch current job.");
@@ -911,13 +911,13 @@ void ServiceManagementService::updateJobStatus(const std::string& jobID)
         if (currentJob->getStatus() == util::ServiceJobStatus::STARTED)
         {
             currentJob->setStatus(util::ServiceJobStatus::IN_PROGRESS);
-            trackedJobCards.getValueAt(jobIndex).state = RecordState::MODIFIED;
+            trackedCurrentJob.state = RecordState::MODIFIED;
             jobStatusUpdated = true;
         }
         else if (currentJob->getStatus() == util::ServiceJobStatus::IN_PROGRESS)
         {
             currentJob->setStatus(util::ServiceJobStatus::COMPLETED);
-            trackedJobCards.getValueAt(jobIndex).state = RecordState::MODIFIED;
+            trackedCurrentJob.state = RecordState::MODIFIED;
             jobStatusUpdated = true;
             serviceBookingCompleted = hasCompletedAllJobs(currentJob->getBookingId(), currentAssignedJobs);
             if (serviceBookingCompleted)