Sacramento has been invaded by Nashville-style hot chicken. The Tennessee-born variety of fried chicken, lacquered in a cayenne-based spice paste and served with pickles, was once a novelty in the Capital Region. Last year, it became almost as easy to find as tacos or teriyaki. There are now four businesses in Sacramento focused on hot chicken, plus one in Citrus Heights, and at least 10 Nashville-inspired sandwiches at other restaurants in the city. Some add a tongue-curling pinch of ghost pepper or habanero to the spice blend, others temper the heat with a salve of ranch or Thousand Island dressing. One place slips potato chips between