Add documentation headers across system modules

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/UserManagementService.cpp

@@ -1,8 +1,27 @@
+/*
+File: UserManagementService.cpp
+Description: Implements the UserManagementService class which manages user-related operations
+			 in the Vehicle Service Management System. Provides functionality for retrieving user notifications
+			 and deleting notifications by ID.
+Author: Trenser
+Date: 20-May-2026
+*/
+
 #include <stdexcept>
 #include "UserManagementService.h"
 #include "User.h"
 #include "Vector.h"
 
+/*
+Function: getUserNotifications
+Description: Retrieves all notifications associated with a given user ID.
+Parameters:
+	- userID: The unique ID of the user whose notifications are to be retrieved.
+Returns:
+	- util::Vector<Notification*> containing all notifications for the user.
+Throws:
+	- std::runtime_error if no user is found with the given UserID or if the User object is invalid.
+*/
 util::Vector<Notification*> UserManagementService::getUserNotifications(const std::string& userID)
 {
 	auto& usersMap = m_dataStore.getUsers();
@@ -28,6 +47,17 @@ util::Vector<Notification*> UserManagementService::getUserNotifications(const st
 	}
 }
 
+/*
+Function: deleteNotification
+Description: Deletes a specific notification associated with a given user ID.
+Parameters:
+	- notificationID: The unique ID of the notification to be deleted.
+	- userID: The unique ID of the user whose notification is to be deleted.
+Returns:
+	- void
+Throws:
+	- std::runtime_error if no user is found with the given UserID or if no notification is found with the given NotificationID.
+*/
 void UserManagementService::deleteNotification(const std::string& notificationID, const std::string& userID)
 {
 	auto& usersMap = m_dataStore.getUsers();