Approve or deny AI-proposed document changes one-by-one or in batch (HITL workflow).

Used with chat_async when approval_mode='ask_every_time'. For each proposed change (with chunk_id and HTML diff), respond approved=true|false plus optional feedback for the AI to revise on. Approved changes apply atomically; denied changes are discarded; the AI may revise based on feedback in the next turn. Required for regulated workflows (legal, medical, compliance) where every AI edit must be reviewed before it touches the document. For single changes: set approved=true/false and optionally provide feedback. For batch decisions: provide a 'changes' array with per-change decisions. After approval, the job resumes processing and eventually reaches status=completed.