MessagePosted for an action that opens a follow-up modal in place.
Some actions (those in IN_PLACE_ACTIONS, currently ENTER_API_KEY)
push another modal, such as the API-key prompt, on top of the
still-open center. Dismissing the center first would drop that stack,
so Esc in the follow-up modal would fall through to the base screen
instead of returning here. The app handles this message by dispatching
the action while the center stays mounted, then reloading it with the
refreshed registry snapshot.