- Fix: clicking friends tab now always shows friends scene (not
  notifications). Tab click resets to root when already active.
- Friends list: sorted online-first, shows count, retry on error
- Pending requests: fetches requester profiles (name, avatar, level)
  instead of showing raw UUIDs
- Search: searches both username and display_name, debounced input
- Online tab: auto-refreshes every 15s
- Activity feed: timeAgo formatting, action icons
- API: added 'profiles' action for batch profile lookups, search
  now matches display_name too
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>