Trial account limits and seen-by avatars

Trial and group-creation limits

New accounts (less than 7 days old) can now only create one trial-plan top-level group, unless they already belong to a paying group. Separately, cancelled or inactive memberships now count toward a trial group's membership limit, so the limit can't be bypassed by leaving and rejoining. These changes target spam and abuse account creation and don't affect established or paying groups.

Seen-by and notification history

The "Seen by" and "Notification history" views, opened from a thread's action menu, now display member avatars, and notification history shows read/unread status per recipient.