Boston firefighters rescued a woman from the Red Line tracks at the MBTA’s Shawmut Station in Dorchester Thursday after she entered the track area while a train was pulling to a stop. MBTA spokesman Joe Pesaturo said it was unclear why the 44-year-old woman ended up on the tracks as the first northbound train of the day entered the station at 5:19 a.m. The rescue, performed by Boston firefighters, was straightforward and did not require the train to be moved, Boston Fire Department spokesman Steve MacDonald said. The woman sustained minor injuries, and train service resumed before 6:30 a.m., Pesaturo said.Todd Feathers can be reached at email@example.com. Follow him on Twitter at @ToddFeathers.