Changing the disk cache size (library.preferences cacheMb) re-attached a
new PreviewCache object, and the renderer treats a new cache object as a
library reset: every texture, the loupe included, was dropped and
re-rendered. Thumbnails are keyed by content, so a new budget leaves them
valid. The budget now changes in place on the attached cache (same object,
same generation); the next write trims to it, as before. A preview clear,
a generation bump and a new library still invalidate.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>