Bombs detonated in the centre of Boston are disarmed by bonds of family and community in Peter Berg’s “Patriots Day,” a stirring ode to civic life in the age of terrorism. “Patriots Day,” which recreates the 2013 Boston Marathon and the subsequent four-day manhunt, is the third in a string of docudramas for Berg, following the Navy SEAL drama “Lone Survivor” and the recent oil rig disaster film “Deepwater Horizon.”