Connecticut's trash-to-energy agency is seeking a 21st-century makeover for its Hartford plant as it grapples with shifting recyclable and energy markets that undercut its finances. More than a decade after its predecessor agency lost $200 million in a deal with bankrupt energy giant Enron, the Materials Innovation and Recycling Authority, which handles trash from more than 50 municipalities, is looking to hire a company to redevelop the waste-to-energy plant in Hartford and other facilities.