A powerful San Francisco group is unleashing $10 million this year to kill taxes that they say will destroy the city’s fragile economic recovery — and potentially increase the price of food and goods for already cash-strapped residents. Neighbors for a Better San Francisco, a moderate advocacy group, plans to beat back a wave of lefty initiatives and candidates this year that they say will derail years of progress in liberal San Francisco, according to its director Jay Cheng. One of the group’s