Track auto upload files when original file is "kept in original folder" #12967

Is your feature request related to a problem? Please describe.

The On Device feature is currently the only way for me to (relatively) quickly clear local files to save space on my device. However, auto upload files using the kept in original folder option do not track the original source file in a way that is compatible with the On Device feature. In order to remove these files, I must manually delete them after checking to see if NextCloud uploaded them.

Describe the solution you'd like

I would greatly appreciate if files synchronized via auto upload would be mapped to the original file in a way that allows the file to show up in the On Device feature. This way, I can choose when to delete files that have been uploaded regardless of their current location. Once the file no longer exists on the device (whether from cleanup or deletion by another app), the mapping can be discarded and future downloads can use the NextCloud data folder.

Describe alternatives you've considered

I have considered using the deleted option for original files, but that risks an error resulting in lost files which defeats the purpose of NextCloud as a backup. I prefer to manually review the upload errors to resolve problems and then clear the space myself.

I have attempted to use the moved to app folder option, but it complicates the use of other apps when interacting with the original files. For example, I might use an app similar to Google Photos as my primary way to interact with on-device media, while using NextCloud to backup to a private cloud. That app may expect to find media in the typical system folders and - while it might be able to access media in other folders - the user experience is significantly diminished.

Additional context

N/A