Review follow-up (Leonie, Felix, Markus): bump cheatsheet key caps to text-sm
for the 60+ audience, add a focus-visible ring to the close button, simplify
the draw-hint guard to {#if drawArmed} (the $effect already clears it outside
edit mode), and document why the transcribeShortcuts action ignores its node
and binds to window.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>