Optional JSON interaction traces for textinput regressions

[PerchAnton]

I maintain interaction-check, a small experimental Python test runner. I am preparing a Go adapter that sends events to the real textinput Model.Update and records its value, rune cursor position, focus and width.

Would an optional adapter for replaying short bug reports be useful here? Native Go tests would stay. Python would only be needed for these extra traces. I can share the tested adapter before proposing a PR.