CommitRule::AnyMember (WAI live-messaging §7.2) beside the room's lowest-leaf
rule (confidentiality §5.5, the default): RoomMember and Clock check commits by
the rule their model holds, and a page's E2eeMember opts in with
anyMemberCommits(). A model test holds both rules.
Co-Authored-By: Claude Opus 5.5 <[email protected]>