Local salsa star Fran Pritchard is moving up the food chain in a big way.The owner of Gardnerville-grown Killer Salsa announced this week that her product would be expanding into Walmarts in Las Vegas and select Walmart stores in Sacramento, San Francisco, Napa, Modesto, Fresno and San Jose, totaling more than 50 new stores. Put another way, the small company's 389 cases of shelf-stable salsa shipped out on July 3 represents roughly a 60 percent increase in market exposure. Whether sales follow suit is another story. "I'm nervous-slash-excited," Pritchard said Friday. "I'm contemplative. It will be another challenge, one of …