Well, that was quick. Maura Healey has been on the job less than a week, but we don't have to wonder where she stands on the biggest health care conflict in Massachusetts. The new state attorney general made it clear Monday that she doesn't like the proposed merger of the giant Partners HealthCare System with South Shore Hospital in Weymouth and two other community hospitals north of Boston. The deal was explicitly endorsed by her predecessor, Martha Coakley, with lots of strings attached. Critics of the arrangement — including the state Health Policy Commission and Partners' rivals — say it will allow the giant to become even bigger, making medical care more expensive for everyone in Eastern Massachusetts.