Why: U2A succeeded on RDM (1d9de398) so U2B can proceed using the stable RoleAuthority interface. Evidence: U2A child card .task/feature-iam-role-permission-linked-capabilities-u2a-perms-and-perms-api.md (terminal_status=success, transport.commit=1d9de398). Impact: U2B dispatch ready; targets system_projects/projects_api/project_resource_authz/settings_duties/runtime/plugins/rdm entry points; pins/* materialized for compilation. Refs: plan revision 3 U2; PR #628.