saveLastClientId function
Saves the last used client ID to a file.
This function writes the provided clientId to the last_client.txt file
located in the ./clonify/ directory. This allows the CLI to remember
the last active client for convenience.
Note: This function is duplicated in clonify_core.dart. Consider refactoring.
Throws a FileSystemException if the file cannot be written.
Implementation
Future<void> saveLastClientId(String clientId) async {
final file = File('./clonify/last_client.txt');
await file.writeAsString(clientId);
}