rule_canonical → ng12_canonical collection (ID-based lookup, no embeddings)
Verbatim PDF text for citation display
rule_search → ng12_guidelines collection (filtered by doc_type=rule_search)
Template-enriched text with synonym expansion for better vector retrieval
symptom_index → ng12_guidelines collection (filtered by doc_type=symptom_index)
Symptom-to-cancer mapping with cross-references back to Part A rules