Slide: the residual ~40ms end-of-slide hitch (down from 128ms in b124) was the layer
DEMOTE + the deferred full renderThread at transitionend. Two fixes:
- Keep .content promoted for the WHOLE time a chat is open (will-change lives on
body.chat-open, not on the animating class). The open transition now only changes the
transform VALUE 100%->0; when it ends there is nothing to tear down -> no demote raster.
- Slide-end no longer rebuilds all 40 nodes: reconcileOpen() appends only the 0-2 genuinely
new tail messages (full renderThread only if the page structure diverged).
Download: routing to Safari failed auth (no login cookie). Real fix: fetch the file in the
WebView (cookie present) and hand the bytes to the OS save/share sheet via Filesystem+Share
(added to mobile deps; ships next TestFlight build). Until then, images fall back to the iOS
long-press "Save to Photos" instead of breaking the app.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>