engines

Work for the Project Rubi-Ka engines repository, including PRK.Client and supporting engine services. Completion policy: shipped work should not remain open solely because an old checklist or description says live, user, deployment, platform, or production verification is pending. Treat later user confirmation that the work was deployed/verified as sufficient to complete it. Keep tasks open only for substantive remaining implementation, unmerged dependencies, unresolved defects, or operational work.