Deletions shouldn't be difficult because of the schema. For instance, this query: select display_name, ('https://your.lemmy.host/pictrs/image/' || pictrs_alias) as image_url, pictrs_delete_token from image_upload iu inner join local_user u on u.id = iu.local_user_id inner join person p on p.id = u.person_id; will list all media, with the display name of the user who uploaded them, and the token that can be used to delete the image. Obviously, this needs a where u.id = ? parameter to only expose the list to the right user, but adding a "delete old media" page really shouldn't be that hard. It'll require time, though, and with one of the two devs taking parental leave soon, I don't think there's that much dev time for a while.

The pieces are almost in place, they just need an API endpoint and some UI work.