For Mux AI audio workflows, attach dubbed tracks with a short-lived presigned source URL and name the track clearly. For signed assets in mux-player, sign playback, thumbnail, storyboard, and drm tokens in one call and pass them as player props.

Context: Official Mux AI repo (EXAMPLES.md): documents the agent patterns for AI video workflows. The dubbing example downloads the default audio track, runs a dubbing job, uploads the new audio to storage, makes a presigned URL with a one-hour expiry, and adds the track to the asset. The signed-playback example shows mux.jwt.signPlaybackId with type-specific tokens for playback, thumbnail, storyboard, and drm_license, including the multi-token form that mux-player accepts as props.