A 12-year-old boy who has been in a coma for four months died Saturday at a London hospital after doctors ended life-sustaining treatment that was the subject of a lengthy court battle. Archie Battersbee’s mother, Hollie Dance, said he died at 12:15 p.m. local time, about two hours after the hospital began withdrawing treatment. British courts had rejected the family’s request to transfer Archie to a hospice, and the European Court of Human Rights refused for a second time to intervene in the case. “He fought until the very end,” Dance said, weeping outside the hospital. “I’m the proudest mum…