Adds a reload button to the app titlebar visible only in PWA standalone
or fullscreen mode, and a pull-to-refresh gesture on the messages container
that smooth-scrolls to the top before activating.
The reload button sits next to the message count label and provides a
one-tap refresh for users who installed the WebUI as a home-screen app
where browser navigation controls are unavailable.
The pull-to-refresh gesture detects downward drag at the top of the
message list, shows a visual indicator ('Pull to refresh' / 'Release to refresh'),
and reloads on release past the 80px threshold. When triggered mid-conversation,
it smooth-scrolls to the top first.
c7d0c6343c
