Goal: set the input to react-ok in a way that React would accept.
The page mimics React's _valueTracker: it stamps the input with a
hidden tracker holding the last-seen value. An input event is only
considered "framework-real" if the tracker's recorded value differs from the
current input.value at the moment the event fires
(i.e. somebody used the native HTMLInputElement.value setter and
dispatched input — what React internals require).
Setting el.value = ... directly and dispatching a synthetic input
fails because the native setter wasn't used. Calling setRangeText without
dispatching input also fails.