Contract 0.21.1

Clan notifications actually notify: member_joined, member_left, and member_role_changed now flow to the event feed for clans you've added (the only clan topic before was the WEEKLY war boundary - working as designed, but the design covered almost nothing). Also: every fresh battlelog poll is now capture-audited (was the payload's oldest battle already known?) and the 24h gap count is public on Data > Status.