Per-project Members — the hub's native people surface (P2a).
Members are core users with a project role (owner/manager/member/viewer).
Add by exact email (core account lookup), change roles inline, remove —
all through PhoenixKitProjects.Members, which owns the last-owner guard
and the target_uuid'd activity rows (so membership changes notify the
affected user through core's channels).
Gated on Authz.can?(…, :manage_members) at mount AND per event (this
page writes authorization state). Embeddable like every LV here.