Trigger L0/L1/L2 metadata extraction for a creator's content (or all content when profile_id is null, capped at 200). Admin-only.

BYOK only — each layer runs on the content owner's connected AI key. JubJub never pays. Returns immediately; extraction runs as background tasks.

Skip logic (force=false): a layer already done for a piece is skipped — l0 done = provenance key in media_metadata_v1/{content_id} l1 done = transcript key in media_metadata_v1/{content_id} l2 done = intelligence_status == "complete" in media_metadata_v1 force=true queues every requested layer regardless. Counts are per (content, layer): queued is layer-tasks fired, skipped is layer-tasks skipped (already done, or no owner to bill).