add setting to restrict deletion of external gallery

I have searched the existing feature requests, both open and closed, to make sure this is not a duplicate request.

• Yes

The feature

Hello immich community and 1st of all thanks for everything that you are doing on this amazing project !!
I was wondering if is possible to add a setting which doesn't let you delete in the immich web or app the media which was imported via external gallery... because when you delete it from immich web or app, the picture will come back on the next reindexation and it will never be deleted from the (example) truenas...
in my case, the external gallery is read only to immich server and i would like, when i try to delete a photo which is coming from external library, to have a message telling me that is impossible to delete media coming from external library...
so i will know that i need to go in my truenas and delete the file...

Platform

• Server
• Web
• Mobile