@memberjunction/video-studio-core contains the shared TypeScript contracts (VideoGenerationSpec, VideoBeatTemplate, VideoPacing, and the render worker wire protocol) and pure stage-aware validators for MemberJunction Video Studio. Because this package is imported by both Angular browser clients (@memberjunction/ng-artifacts), server-side engines (@memberjunction/video-studio), and the isolated render worker (@memberjunction/video-studio-render-worker), it must remain strictly environment-agnostic and must never import Node built-ins (fs, path, node:*), database drivers, or server-only MemberJunction packages. See plans/video-studio.md for the full specification.