Designer mixes burnt-out velvet and shredded denim with a mythology that keeps getting more profitableThe opening show of fashion’s month of catwalks was not on the official schedule, but Viola Davis and Cynthia Erivo were snuggled on to celebrity-packed benches in a cathedral-sized marble hall where tapestry-hung walls and a gilded coffered ceiling framed a view over lower Manhattan.Ralph Lauren, 86, took his bow at the end of this women’s wear show casually dressed in a varsity jacket spel