Absolutely unbased take. Please ignore.

Matrix works fine, I have hosted a server on my own for several years through an ansible playbook here.

It kinda seems like it. Docker apparently does have this functionality as seen here: https://stackoverflow.com/questions/40494536/how-to-specify-the-size-of-a-shared-docker-volume/40499023#40499023

You could try limiting it to 5 GB using the forgejo settings and 7GB using docker and then just look, how big it is.

I’ve searched the docs a bit and found this setting: https://forgejo.org/docs/latest/admin/config-cheat-sheet/#quota-subjects-list

It seems to be partially for your case, though I don’t see artifacts, but you could limit all of forgejo to like 5GB and probably be good.

Ugh, with a keyboard and a text editor. Duh!