Do you really need it? Have you tried disabling transcoding? Sometimes clients would be able to direct stream but for some reason it still transcodes.

Check out Trash Guides

It’s not FOSS but take a look at Photosync:

https://www.photosync-app.com/home

See my other comment, nG-firewall does exactly this and more.

https://perishablepress.com/ng-firewall/

Its not AI but take a look at nG-firewall, it blocks most know unwanted stuff and gets regular updates.:

https://perishablepress.com/ng-firewall/

Paperless-ngx

The rest is already in the other comments

This, had the same idea for other purposes, sharing a folder from vm to host through network share is the easiest way. Every other solution looks more elegant on paper but has lots of pitfalls.

I use duplicacy, it’s free as cli and pretty cheap if you want to manage the backup via gui. Restore by gui is always free and I would recommend it because it’s way easier to navigate the backups if you want to restore single files or folders.

Oh and regarding the large TIF files, what limits are you hitting? Most hosters allow to change the php settings like memory limit or max execution time.

As others said, encrypt your backup before sending it to your server. And can’t you upload the files to a folder outside of a document root or better outside of the www folder so there is no way to access it through the web server service?