Direct video and image URLs for an ad

Returns the direct signed URLs for every video and image asset used by an ad's live creative, normalised across shapes: single image/video, carousel, Reels/Story (object_story_spec.video_data) and dynamic creative (asset_feed_spec). Video items include Meta's poster thumbnail and the video's Meta id when available.

Reads Meta live rather than the stored creative blob because Meta's signed fbcdn URLs carry an oe=<hex> expiration (image_url ~24 h, video source ~12 d). Treat URLs as short-lived: re-fetch this endpoint before serving or downloading assets instead of caching URLs beyond that window.