check('收到真实分片后主动结束读取', receipt.get('clientCancelled') is True)
check('半截输出保留为 cancelled 而非 completed', receipt.get('choices', [{}])[0].get('finish_reason') == 'client_cancelled')
result = {'status': 'cancelled', 'partial_text': output, 'billing': 'unknown: stream cancelled before final usage'}
