Detailed error reporting for failed device list imports

NetBrain's device list import wizard does not provide feedback when an import fails, leaving users unable to determine which line or device caused the failure, including cases involving duplicate entries. This enhancement would add a detailed error message to the import process that identifies the specific line, device, or condition (such as a duplicate) causing the failure. Customers would be able to correct import issues directly rather than manually checking each device one by one, reducing troubleshooting time and improving the reliability of bulk device onboarding.