Long-Running Operation: 202 + Poll thay vì chờ request
POST → 202 + Location(operation) → poll (Retry-After) → succeeded + result link
Phím tắt: ←/→ từng bước · Space tự chạy/tạm dừng
POST → 202 + Location(operation) → poll (Retry-After) → succeeded + result link
Phím tắt: ←/→ từng bước · Space tự chạy/tạm dừng