Containers don't even really help that much because they share the host file system. Need a VM, and even then, agents have escaped them!

They only do if you give your container that file system as a volume.

Unless i'm misunderstanding, the only way to get durable collaboration with agents is via the file system. I just mount the subdirectory that contains the source code we are collaborating on, rather than my home directory that contains my .ssh directory, etc.