readStateManagement static method
Reads state management from .sm_cli_config.
Returns 'Riverpod' if config file not found.
Implementation
static String readStateManagement(String projectName) {
final file = File('$projectName/$_configFile');
if (!file.existsSync()) return 'Riverpod';
final config = jsonDecode(file.readAsStringSync());
return config['state_management'] ?? 'Riverpod';
}