A statewide Realtor advocacy group is applauding the state Supreme Judicial Court's decision this week to upheld a lower court's ruling regarding real-estate agents' decision to affiliate as independent contractors. The Massachusetts Association of Realtors said the SJC's decision in Monell vs. Boston Pads LLC is a win for consumers and the entire real-estate industry, saying the ability for real- estate agents to choose to affiliate with real-estate brokers as independent contractors has been the backbone of the profession for more than 100 years.