Fix View Stock Level and improve error messages

- Added validation in AdminMenu::viewStockLevels to check for empty inventory before displaying.
- Added validation in AdminMenu::viewStockLevels to ensure only active items are shown.
- Added "View Stock Level" header for clarity.
- Adjusted column widths for Quantity and Price to 15 for better alignment.
- Added final newline and util::pressEnter() prompt after displaying stock levels.
Fixes  #1739

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/AdminMenu.cpp

@@ -158,10 +158,33 @@ void AdminMenu::viewStockLevels()
 {
     util::clear();
 	auto inventoryItems = m_controller.getInventoryItems();
+	bool hasActiveItems = false;
+	std::cout << "View Stock Level" << std::endl;
+	if (inventoryItems.isEmpty())
+	{
+		std::cout << "No items found in Inventory.\n";
+		util::pressEnter();
+		return;
+	}
+	for (int index = 0; index < inventoryItems.getSize(); index++)
+	{
+		const InventoryItem* item = inventoryItems.getValueAt(index);
+		if (item->getState() == util::State::ACTIVE)
+		{
+			hasActiveItems = true;
+			break;
+		}
+	}
+	if (!hasActiveItems)
+	{
+		std::cout << "No active Inventory Item found.\n";
+		util::pressEnter();
+		return;
+	}
 	std::cout << std::left << std::setw(15) << "Item ID"
 		<< std::setw(25) << "Part Name"
-		<< std::setw(10) << "Quantity"
-		<< std::setw(10) << "Price"
+		<< std::setw(15) << "Quantity"
+		<< std::setw(15) << "Price"
 		<< std::endl;
 	for (int iterator = 0; iterator < inventoryItems.getSize(); ++iterator)
 	{
@@ -172,12 +195,14 @@ void AdminMenu::viewStockLevels()
 			{
 				std::cout << std::left << std::setw(15) << item->getId()
 					<< std::setw(25) << item->getPartName()
-					<< std::setw(10) << item->getQuantity()
-					<< std::setw(10) << item->getPrice()
+					<< std::setw(15) << item->getQuantity()
+					<< std::setw(15) << item->getPrice()
 					<< std::endl;
 			}
 		}
 	}
+	std::cout << "\n";
+	util::pressEnter();
 }
 
 /*