Very cool! A couple first-blush bits of feedback:

- The editable text fields currently lose focus after each keypress

- Error handling will be a hard nut to crack, but currently if you, say, add "a" to an editable textbox that expects a number, the live component reverts to text

- Minimal support for buttons would add a lot for simple interactive charts - something like:

    ::button
    label="Set x to 5"
    x = 5
    ::