Brit fashion favorite and Karl Lagerfeld muse Alexa Chung has landed her own fashion reality show on Lifetime, the home of Heidi Klum’s “Project Runway.” Chung will host the show provisionally called “24-hour Catwalk,” where designers will compete against each other in runway challenges. Sources said the new program, which will also feature creative talents such as Cynthia Rowley, will premiere this fall, but Lifetime declined to comment.