- Every message now shows a Slack-style time (clock today, then 'Yesterday',
weekday, else a date; full timestamp on hover).
- New ConversationSettings panel for groups AND channels (public + private):
rename, member list, add people (from the directory), remove, and leave.
Opened from a new thread header gear; DMs show no gear. Adapter gains
addMember/removeMember/renameConversation (optional, OPA still gates writes).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
