- Use 100dvh with 100vh fallback to fix composer being cut off on
mobile browsers where the address bar affects viewport height
- Add comprehensive @media(max-width:640px) rules: topbar wrapping,
compact messages, full-width msg-body, smaller chips and buttons,
responsive composer, approval cards, tool cards, settings modal
- Use font-size:16px on textarea to prevent iOS/Android auto-zoom
on input focus (browsers zoom when font-size < 16px)
- Add .topbar-left class on title wrapper for responsive stacking
f6e58ef2ad