The graph schema uses a DERIVED_FROM edge from one CxU to another so that lineage between derived and source context units is preserved.

**Key edges:**

— PYRANA_PLATFORM_ARCHITECTURE_REFERENCE.md

DERIVED_FROM: CxU → CxU (lineage)

— PYRANA_PLATFORM_ARCHITECTURE_REFERENCE.md

### Graph Schema (Neo4j)

— PYRANA_PLATFORM_ARCHITECTURE_REFERENCE.md