Added employee persistence, serialization, and file loading support

<SRS>SRS02 : Employee Management </SRS>

<Changes>
 - Implemented serialization and deserialization for Employee and GeneralEmployee models
 - Added FileManager integration to load employees from CSV files
 - Introduced ApplicationConfig entries for employee file paths
 - Updated Employee ID handling (getEmployeeId → getId) across project
 - Modified FileIO to auto-create file if not found instead of throwing exception
 - Added constructors for all employee types to support deserialization
 - Implemented loadEmployees in service and loadStates in controller
 - Ensured default admin creation if none exists during load
 - Added StringHelper utility for extracting numeric IDs
 - Extended Enums with string conversion and parsing utilities
 - Added initial CSV files for Employee and GeneralEmployee data
 - Improved login error message formatting and minor cleanup
 - Setup gitignore to not track csv files
</Changes>

Trenser.Zenvy/Trenser.Zenvy/views/FinanceExecutiveMenu.cpp

@@ -49,7 +49,7 @@ std::string FinanceExecutiveMenu::getSelectedUserId()
 	for (const auto& employee : employeeList) 
 	{
 		std::cout << std::left << std::setw(6) << employee.first
-			<< std::setw(15) << employee.second->getEmployeeId()
+			<< std::setw(15) << employee.second->getId()
 			<< std::setw(25) << employee.second->getEmployeeName()
 			<< std::endl;
 	}
@@ -58,7 +58,7 @@ std::string FinanceExecutiveMenu::getSelectedUserId()
 	auto employeeIterator = employeeList.find(choice);
 	if (employeeIterator != employeeList.end())
 	{
-		return (employeeIterator->second->getEmployeeId());
+		return (employeeIterator->second->getId());
 	}
 	else
 	{

Trenser.Zenvy/Trenser.Zenvy/views/MenuHelper.h

@@ -63,7 +63,7 @@ inline std::map<int, std::shared_ptr<const Employee>> listEmployees(const std::s
     {
         std::cout << std::left
             << std::setw(5) << index
-            << std::setw(15) << activeEmployees->getEmployeeId()
+            << std::setw(15) << activeEmployees->getId()
             << std::setw(25) << activeEmployees->getEmployeeName()
             << "\n";
         employeeList[index] = activeEmployees;
@@ -90,7 +90,7 @@ inline void deactivateEmployee(const std::shared_ptr<ZenvyController>& controlle
     auto iterator = employeeList.find(choice);
     if (iterator != employeeList.end())
     {
-        std::string id = iterator->second->getEmployeeId();
+        std::string id = iterator->second->getId();
         bool success = controller->deactivateEmployee(id);
         if (success)
         {

Trenser.Zenvy/Trenser.Zenvy/views/UserInterface.cpp

@@ -19,6 +19,15 @@
 void UserInterface::run()
 {
 	bool isMenuActive = true;
+    try
+    {
+        m_controller->loadStates();
+    }
+    catch (const std::exception& e)
+	{
+	    std::cout << "Exception: " << e.what() << std::endl;
+        return;
+    }
 	while (isMenuActive)
 	{
 		try
@@ -94,7 +103,7 @@ void UserInterface::login()
         }
         else
         {
-            std::cout << "\nInvalid Password";
+            std::cout << "Error: Invalid Password\n";
             util::pressEnter();
             return;
         }