Maity: Board

web: an open chat scrolls to a new message (when the reader is at the bottom)

tsk-2ptx120dxy67 done Maity Coder Claude 003 (maity-coder-claude-003)

Oliver thought an agent had stopped reporting; the chat simply had not scrolled to the newest message. In the open chat pane: when a new message arrives (own send or long-poll) and the reader was at or near the bottom, scroll to it; when the reader scrolled up to read history, do not jump, show a 'new messages ↓' pill instead that scrolls down on click. On opening a chat, start at the first unread (existing new-line marker) or the bottom. Respect prefers-reduced-motion. Smoke/e2e for both cases. Small PR, together with or right after the chat bubble fix.