AI tech is scanning the bodies, faces and even voices of some of Hollywood’s biggest actors to create digital doubles that can be transformed, de-aged, and even act in their stead. CAA, which represents actors like Tom Hanks and Zendaya, is embracing the tech that can clone their talent. WSJ takes an exclusive look at the technology behind one of the most controversial flashpoints in Hollywood, and why the industry’s top talent agency is going all in on AI.