Candace Bushnell’s new book is such a thinly disguised version of her life as a woman of a certain age rediscovering the joys of Manhattan from her Upper East Side apartment that some publications reviewed it as “non-fiction” before quickly correcting their error and putting it in the “fiction” category (it didn’t exactly help that the back cover describes this as a “memoir”, compounding the confusion). It’s an easy mistake to make, though. The narrator of this “novel” is transparently a fictional avatar of Candace Bushnell herself. And in case the reader has any doubts, the middle-aged, single white woman