[3 + 4 h.] logging the start_time of the operation in Manifest

- [ ] Добавить в манифест поле start_time для корректного отображение операции в orders view

- [ ] обеспечить отображение операции в orders_view с учетом start_time и end_time

Find the Manifest model and add a start_time field. Update the orders_view to display operations using both start_time and end_time. Look for existing models with timestamp fields and the view logic that handles operation ordering.

Written by the indexing model from the issue text.