Doris F. Fisher, who cofounded Gap in 1969 with her late husband Donald Fisher and steered the business into becoming a household brand name that ultimately redefined America’s casual dress code, died Saturday in San Francisco at the age of 94. Gap Inc. on Monday confirmed Fisher’s death and indicated that she died peaceably surrounded by family. The retailer got its start when Fisher’s husband became frustrated that he could not find jeans that fit him. He left behind a career in real estate development and entered retailing, with his wife firmly believing that opportunity existed for a store that could provide shoppers with a variety of fit and style options. The couple raised $63,000 to launch the Gap in 1969 with one small store at 1950 Ocean Avenue in San Francisco, primarily selling Levi’s jeans, vinyl records and cassettes with a particular appeal to the counterculture youth of the day. The store performed well, encouraging the Fishers to open a second Gap store in 1970 in San Jose, Calif.…