- Both now read and write one setting, so they cannot disagree
- An image background reads as blur off there; turning blur on replaces
the image, which is what FR-022 and EC-011 ask for
- The new setting defaults to whatever blur the user already had, so
nobody loses the blur they turned on before this existed
- Covers the derivation with tests: what the checkbox shows, what it
writes, and the fallback when a stored background is one we no longer
ship
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>