[§9.7] Temporal KG pipeline on Twin; graph queries via retrieve.graph

[mdheller]

Agentic-Stack §9 action 7 (Emergence stratum). KG-builder pipeline: percentile_chunk→validate→entity_resolve→triplets, feeding retrieve.graph in the RAG loop. Accumulates estate institutional memory as navigable typed triples with temporal validity. Part of epic SocioProphet/socioprophet#490.