For the workers fortunate enough to remain employed at Carrier’s Indianapolis factory, which Donald Trump singled out as a symbol of American manufacturing distress in 2016, these should be the best of times. The assembly line is churning out furnaces seven days a week, overtime is abundant, and shares of Carrier are soaring even as Covid-19 ravages the overall economy.But that’s not how Anthony Cushingberry, a 24-year veteran of the factory floor and a union steward, sees it. “The trust left a long time ago,” he said recently after completing a 10-hour shift as a materials associate, taking …