Returns DuckDB DDL for the focused ClinVar schema. Public identifiers and domain relations are retained directly: VCV variants, alleles and assembly locations, genes, RCV aggregates, SCV submissions, conditions, observations, citations, attributes, and attributable discovery text. XML parser nodes are not persisted. The release catalogue enforces its small primary key; the release-scale analytical tables expose logical key columns without DuckDB ART indexes so complete imports remain memory-bounded.