Possibility to request a file index

At the moment, it is possible to request all the files of a record

<img width="1460" height="341" alt="Image" src="https://github.com/user-attachments/assets/f4737abd-b972-46fe-9d5b-fb9fb813fe53" />

Some records have a lot of files (up to 20k). It would be better if there was an option to request only some of the files, like requesting only one file_index for instance