known = {row['id'] for row in data['messages']}
broken = [row['id'] for row in data['messages'] if row['reply_to'] and row['reply_to'] not in known]
missing_parents = [row['reply_to'] for row in data['messages'] if row['reply_to'] and row['reply_to'] not in known]
check('缺失父ID与孤立消息正确区分', output['broken_parent_ids'] == missing_parents)
result = {**output, 'orphan_message_ids': broken}
(folder / 'thread-summary.md').write_text('当前期限：' + output['current_deadline'] + '\n\n' + output['summary'])
