Law Roach has long identified as an “image architect,” but Magnum amended that title for Cannes by appointing the veteran power stylist as the ice cream brand’s “taste architect” for its annual festival activation. As part of his duties, Roach touched down on the French Riviera on Thursday to curate Magnum’s first-ever fashion show as creative director by overseeing the design and curation of the presentation “in celebration of the House of Magnum.” The show took place on a particularly windy day at Magnum Beach (Palais Stéphanie on the Croisette), where the runway was filled with models decked out in designs inspired by Magnum flavors and created by eight designers hand-picked by Roach. The trend setter even closed the show in a lively moment by walking hand in hand with his Project Runway pal Heidi Klum, who made a surprise showing.…