List UGC reaction clips

Returns short clips of a person reacting to camera, split into system (the built-in library) and custom (reactions you generated). Pick one by id and use it as reactionId in POST /ugc/videos to build a finished UGC hook video. The name and tags describe the person and the reaction, so you can choose one that fits your hook. For your own reactions, check status (pending, processing, completed, or failed); built-in reactions are always ready.