Previous pass moved to JPEG + startTransition but the grid still froze.
Root causes that survived:
1. React.memo was broken — the parent re-created the inline
`onClick={() => onSelect(src.id)}` arrow on every render, so memo's
reference check always triggered a fresh render on every card even
though nothing visible had changed. Fixed by passing `onSelect` as a
stable prop and constructing the click handler inside the memoized
child.
2. 20 data-URL `<img>` sources getting decoded more or less at once gave
the compositor enough work to make scroll feel laggy. `decoding="async"`
punts decode to the browser's image thread; `loading="lazy"` skips it
entirely for cards outside the viewport.
3. Concurrency at 4 was still high enough for Windows GDI BitBlt /
PrintWindow to contend for the desktop compositor — the whole Tauri
window stuttered because the OS-level screen capture was saturating
the graphics pipeline. Dropped to 2 concurrent captures; total load
takes a touch longer but the picker stays interactive throughout.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
byGalax
8b9a40f059