3da22af859
Guarantees the last partial delta chunk is emitted when the SSE stream closes (EOF, break, or `[DONE]` sentinel). * Buffer `last_delta_data` and track `delta_count` * Flush automatically once `delta_count >= chunk_size` * Perform a final flush after the iterator ends Signed-off-by: Sihyeon Jang <sihyeon.jang@navercorp.com>