129b84fd69
ClusterRoleInfo resolved the leader address through Cluster.State.Members, which is published asynchronously; a miss stored null permanently, so RoleLeader(role) stayed null (flaky test timed out under load: 6/10 failing with CPU contention, 0/20 after). Only the address is ever read, so store it directly. Adds a deterministic unit test (fails without the fix) and InternalsVisibleTo for the Cluster.Tests project. Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe