It should have been an uplifting moment when the door to the Browns’ weight room opened at 10:30 a.m. Tuesday and LeCharles Bentley sauntered onto the practice field after two years in oblivion. But even as Bentley began what could be an amazing comeback from a torn patellar tendon and three more surgeries for a life- and limb-threatening staph infection, there was an underlying uncertainty. Not about Bentley, a 28-year-old St. Ignatius High School product, playing football again, but whether it will be for his hometown Browns