Does anyone have a suggestion for a harness that is good at handoff?

When I say handoff, I mean:

  * handoff from a terminal CLI to webui (on a phone)? 
  * handoff from one team member, to another?
  * handoff from one communication modality, like writing a prompt in a TUI, to email? 
  * handoff from one model to another, or one provider (openrouter)( to another (llama.cpp)

Does such a thing exist?

I used to think that a PR would be a good place to centralize all this. Who cares what IDE, or developer, or location. But, now I feel like an agent harness might contain that better.

Why do I want handoff? I keep losing context of where my harness is running. Sometimes I am inside an isolated VM. Sometimes I'm on my laptop, sometimes I'm on my home machine with the big GPU for local models. If I could spin up a harness that could identify itself inside my tailscale network, then I could probably have a single web UI which allows me to keep all that context straight.

I'm tempted to experiment with Pi to configure such a thing. But, perhaps there are patterns out there already with a harness I have not considered.