Hello!

This project looks cool. My use case is rather specific and odd so feel free to discard, incorporate or advise.

Imagine a VSCode or other editor. In this editor you have a single workspace with two repos added to the workspace. Thus the agent has access to both codebases. Let's call one repo 'Parent9000' and the other 'Child8000'. Parent9000 runs on port 9000 and as you'd expect generally iframes in the child (although may not always have the child in the frame or even have any frame on the page). Child8000 runs on port 8000 and is generally iframed in by the parent (although may not always be framed in or even rendered at all in the browser if the parent isn't framing them in).

This means that clicking on a button in one frame could send a postmessage to the other or vice versa resulting in dom updates (or not). So I might ask, when I click the 'Send Post' button in the Child8000 what dom changes in the Parent9000. In the browser when interacting with an element I might want to find the source but that would depend on what frame it was in.

I think that sort of gets across the basic idea here. Other things that would be cool is getting the urls of the various frames since they will change hash's, query params, etc. Not sure if the security model would let you do all of this, but I can dream.