Add --hints-text-background-color option (default: auto) that can apply
a background color to the matched text after the hint label. This makes
it more clear exactly which text each hint covers.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
We now buffer the key events until the kitten tells us it is ready.
Without this the key presses are delivered to the underlying window
as the kitten's overlay window was not being focused until the kitten
set the ready message.
Fixes#7089
