Feedback from #feedback-app:

"nit, non HoA release blocking, clicking 'sync light/dark theme with os' when dark is selected and os is in light mode leaves these items with the wrong colors - compare to 2nd screenshot where I first selected 'light' before clicking sync checkbox"

The screenshot shows the theme picker where rows retain incorrect color treatment after enabling sync under this state transition.

Slack message: https://warpdev.slack.com/archives/C08KTPNQN65/p1776125492584129

What needs to be done:

• Reproduce the state transition bug (dark selected + OS light + enable sync).
• Ensure theme preview/list item colors recompute immediately when sync is toggled.
• Verify both transition paths produce consistent colors (with and without manually selecting light first).

Linear: APP-4053