In a window-wrapped corner space next to the recently expanded Spinasse (which now has a new, open pasta-making station, but retains its utterly charming trattoria), chef Jason Stratton has debuted Artusi, a drop-in-friendly, wildly decorated—zebra-patterned walls, ceilings hung with tubular light fixtures—aperitivo bar. Stratton, named one of Food & Wine magazine’s best new chefs of…