- Replace virtua with @tanstack/react-virtual for chat history on all
surfaces: bottom anchoring (anchorTo: end), key-stable prepend
preservation, and native iOS touch/momentum deferral live in the core
- Patch virtual-core to clamp the render range to real scroll bounds
during transient adjustments
- Rows render in normal flow inside a translated wrapper so sticky user
headers keep working; measurement snapshots cached per session
- Pre-write container height in scrollToFn so the browser cannot clamp
anchor corrections to the stale height; hold the prepend anchor for up
to 180 frames on mobile while fresh rows settle (cancelled by user
input; desktop relies on core anchoring alone)
- Adaptive row-size estimate from per-session measured averages; disable
reveal fade-in for virtualized history rows
- Mobile loads older history only through an explicit localized top
button: no scroll-position trigger and no post-mount background
prepend, so every insert happens from a resting state; a quiet-window
hold defers any stray prepend commit while a touch gesture is active
- Desktop/VS Code keep the seamless scroll-up trigger and progressive
background prepend
