When Heirloom opened in 2015, some wondered if Lewes could support a fine-dining, farm-to-table concept.  The town rolls up the streets by 10 p.m., even in summer, and Rehoboth Beach had claimed culinary bragging rights. Not only did Heirloom prove them wrong, but Meghan Lee’s restaurant remains fresh and inventive. Clearly, customers haven’t suffered from a seven-year itch. Indeed, although …