Share this: BROOKLYN — The Boston Celtics have a plan. And despite the endless rumors and smokescreens, they’re sticking to it. (For now, anyway.) For the second consecutive year, the C’s entered draft night at Barclays Center with third overall pick and actually employed it, taking Duke forward Jayson Tatum at No. 3 in the 2017 NBA Draft on Thursday. Tatum was one of four total selections for president of basketball operations Danny Ainge, who, as usual, kept Celtics fans on the edge of their seats amid reports he might try to trade for Kristaps Porzingis or Jimmy Butler. Ainge went with the safe bet, though, spurning the more athletic but more volatile Josh Jackson to take a well-rounded 19-year-old who appeared mature beyond