An adversarial review found that with Automatic the neighbour prefetch asked for
the full source level, whose single cache slot then evicted the open photo's
source, and that hover / Before renders and every window-resize pixel produced
full-size renders. Prefetch and stand-ins are now capped at the preview source
level and the loupe size is rounded up to a 64 px step.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>