I made a tool to bubblewrap any agent (well, any agent I've used more than once), so I can run them in whatever YOLO mode they have with a pretty reasonable level of safety (it protects the rest of the system against prompt injections and supply chain attacks, it can't and doesn't try to protect the project being worked on from either). https://github.com/swelljoe/flar
This looks great!
I have a half-assed bwrap-based solution of my own, but flar seems much more thorough, and I like that it's a single binary with sensible defaults.