- viewer.html shows account name in header
- viewer.js loads account list from /api/accounts, auto-selects first account
- Account-aware API endpoints (/api/accounts/{id}/... or legacy /api/...)
- Chat list redesign with avatar initials, preview text, time, message count
- loadViewerAccount() helper fetches account info and user ID
- Chat bubbles with 1px border-radius, angular tail arrows
- Own messages right (blue), others left (dark) via sender_id vs user_id
- Reply preview with left border accent, clickable scroll to original
- Infinite scroll up via IntersectionObserver on scroll-sentinel
- Date separators (Today/Yesterday/date) between messages
- Full-height messages panel with sidebar (channels) + header
- Backend: reply_to_message data in load_messages(), user_id exposed in auth snapshot
- Auto-scroll to bottom on channel load (triple scrollTop fallback)
- history.scrollRestoration = manual to prevent mid-page jumps