You'll notice
Closing the theme picker now always cancels its live preview, even if closed unexpectedly
What
The theme picker now cancels its in-progress theme preview whenever the component is removed from the screen, in addition to the existing cases where cancelling was already handled explicitly.
Why
This prevents a theme preview from being left active if the theme picker closes in a way that wasn't already covered by explicit cancel handling, avoiding a stuck or lingering preview state.