June 2026 monthly summary for coleam00/archon: Delivered foundational Archon Studio workflow builder data model with multi-variant support and robust validation, establishing a scalable baseline for future enhancements and ensuring round-trip fidelity across data layers. Implemented discriminated-union node variants (loop, approval, cancel, script) alongside existing kinds, with pure-function validation and typed fixtures, all without introducing new dependencies. Added cancel variant, expanded test coverage (40+ unit tests across builder validation and round-trip checks), and resolved key reviewer feedback to stabilize the data layer. This work enables safer, production-ready workflow authoring in Archon Studio and provides a clear pathway for future features (validation, UI wiring) while reducing risk of data drift during serialization/deserialization.