Traci Repko gave birth, as expected, to a baby boy yesterday up in Washington state. It weighed seven pounds and was named Tyler Jason Repko. His father is expected back in camp in the next day or so. Meanwhile, the Garciaparra twins, Ava and Grace, who will turn a year old on March 27, made their first Dodgertown appearance, being pushed around the back fields in a double stroller this morning by their mother, Mia Hamm. One of the most famous athletes in the world, Mia nevertheless seemed to move about unfettered. It might have helped that a few feet away, a long line had formed at a table where Tommy Lasorda was signing autographs. Forget the estimated $115 million Frank McCourt is spending on this team. Forget the club’s ballyhooed new manager Joe Torre. After all these years, Tommy still owns Dodgertown — and a case could be made that he is still the biggest star here.