The clothes we're seeing in stores now were conceived on the New York runways last spring when designers trotted out their vision of what the fashionable woman should be wearing this fall. They showed their best intentions, hoping the press, paparazzi and retail bigwigs would buy into their fantasy. The runway displays were a great show of talent, taste and hype produced by the very best of america's designers. the models were gorgeous, the scene exhilarating and the clothes of superb quality. So what went wrong here? Even the best designers have bad days. Blame it on dress stress.