Most folks can tell if they’ll be late to work by the length of the line at Dunkin’ Donuts. That’s why “coffee regular’’ is such a comforting phrase. For anyone who’s lived here more than a week, “coffee regular’’ means “coffee with cream and sugar.’’ It doesn’t save you much time. It isn’t jargon for something super complicated for the coffee purveyor. It’s just a short, happy note of comfort during the dirge of the morning’s song. It’s part of the region’s rhythm.