[4.0.0-beta6] No event after hx-disable re-enables element; simple focus() after request is no longer possible

In Four, `hx-disable` controls remain disabled throughout `__issueRequest` with no event fired after they are re-enabled. The issue-request sequence is roughly:

- disable elements
- `htmx:before:request`
- await fetch
- `htmx:before:response`
- await response.text()
- `htmx:after:request`
- `htmx:finally:request`
- re-enable disabled elements

https://github.com/bigskysoftware/htmx/blob/85b8378db6ddfe964066017ae63a4cc57827f3e2/src/htmx.js#L579-L662

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`hx-disable` exists to prevent the user from interacting with the form while a request is in flight. One obvious thing one might want to do after the request is completed is re-focus the form element so the user can continue, say, typing in todo list items.

Without any event after the disabled status is removed, this kind of workflow becomes awkward to implement:

```html

hx-on:htmx:after:request="find('form').reset(), setTimeout(() => find('find input').focus(), 0)"
>
```

---

It would be nice if there were some event that fired after the elements are re-enabled.

A few ideas:

- Move enableElements call to before the `htmx:finally:request` event. This would be my preference; IMO "finally" should be fired after all default request behavior is completed.
- Add a new event that fires after all default request behavior is completed. `htmx:finallyfinally:request` (joke)
- Add `hx-disable`-specific event(s): `htmx:{before,after}:{disable,reenable}`. Maybe just `htmx:after:reenable`

---

Related issue: #3363

Start in src/htmx.js around lines 579-662 and trace the __issueRequest sequence, especially the ordering of htmx:after:request, htmx:finally:request, and re-enabling hx-disable elements. Review the related issue #3363 and choose a completion point consistent with the existing event model. Done means a documented event or ordering reliably lets listeners act after the elements are enabled, including the focus workflow described here.

Written by the indexing model from the issue text.