The bar menus at fine-dining restaurants have long been an afterthought, with a smattering of appetizers lifted from the main menu plus a token burger and sandwich thrown in. In recent months, though, some of the city’s most acclaimed chefs have turned their culinary sights on the small plates served over the bar. First it was Craig Diehl at Cypress conjuring up “trotter tots” with boiled peanuts and barbecue pork biscuits at Cypress. Now Sean Brock has joined in with his “snack bar menu” at McCrady’s, a rotating daily selection that has included crispy duck rillette fritters, fried bread and butter pickles, and pork buns. We may never sit in the dining room again.