Device log revealed the truth:
- Keyboard: focusing the <16px composer made iOS ZOOM the page (vvW 428->394, vvTop->74), scrambling
every viewport/keyboard calc. Set all form fields to 16px on mobile -> no zoom -> keyboard math holds.
- Latest messages: on a 500-msg chat atBottom was false because late images grow the thread after the
initial scroll. Now re-pin on a schedule + on each image load while near the bottom.
- Budge already gone (device reported ovf:false).
Build marker -> 2026-07-18-batch109.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>