At 12:45 p.m. on a snowy Thursday in February, every seat in the Sagra Italia dining room is full. Formerly home to Fifth Frame Brewing, 155 St. Paul St. is nearly unrecognizable, transformed into an airy, chic space somehow reminiscent of both Brooklyn and Rome. There’s a cozy sitting area off to one side and mossy green accent walls with galleries of curated art. A glass case near the checkout counter displays pillowy focaccia with an array of toppings.