>Having said that, some components need to live outside the sandbox (otherwise, who creates the sandbox?).

I run a single-node k3d cluster on each of my MacBooks which uses Agent Sandbox[0] to keep harnesses isolated. Harnesses access models through LiteLLM only. I have aliases for `kubectl exec`ing into whatever harness I need.

[0] https://agent-sandbox.sigs.k8s.io