They should be able to use the application they changed.
That sounds obvious, but most coding agent workflows still stop at editing files, running tests, maybe starting a dev server, and reporting back. For web apps, that is not enough.
A human developer does not only inspect diffs. They open the app. They click through the flow. They notice when the wrong tab is open, when a button does nothing, when the page changed unexpectedly, or when the browser is still pointing at yesterday's backend.
AI agents need that same feedback loop.
Browser state becomes coordination state
