How to keep track of downloaded files?

Question

Software design

What are the approaches to storing files that are inserted via wysiwyg?
Here, a person wants to insert a picture into an article, it is loaded through the server into some s3, a link is generated there via cdn to the file in order to quickly be given.
In the database, all this is usually stored in a text field, ready-made html.
Then the person took, and in some other article copied this piece of text, and pasted it into another article.
Six months later, let's say, these articles were deleted.
How to delete an image when it is no longer needed?
After all, you can’t just store absolutely everything, s3, of course, is rubber, but if you don’t delete unused files, I think any company will eventually have terabytes of unused garbage.