General Motors Co on Monday pulled the plug on the Chevrolet Volt hybrid and the Detroit-Hamtramck Assembly plant that builds it, both examples of a costly gamble that is not paying off. GMโs widely touted factory of the future, forced on a town desperate for jobs and hailed decades later by former resident Barack Obama, is set to wind down over the next few years, leaving beleaguered Hamtramck wondering what happened. Detroit Mayor Mike Duggan said at a news conference Monday that he told GM chief executive Mary Barra Monday that โwe moved thousands of people out of that neighborhood...