Dataset-XML reference outputs

These references make the transport and terminology scenarios explicit:

• individuals.json uses the main Dataset-XML and Define-XML fixtures. It emphasizes metadata resolution and structural SDTM conversion; source-derived CDISC: identifiers are expected when no authoritative term is supplied.
• terminology/individuals.json uses in/terminology/. Its first ethnicity is resolved from Define-XML nci:ExtCodeID metadata to NCIT:C41222; its second ethnicity intentionally remains CDISC:ETHNIC.UNKNOWN.

The second file therefore demonstrates both successful identifier lookup and the safe fallback within one small reference output. Keeping the canonical individuals.json filename means both references can be passed directly to the BFF validator from their respective directories.

Run it from the repository root:

bin/convert-pheno \
  -idataset-xml t/datasetxml2bff/in/terminology/dm.xml \
  --define-xml t/datasetxml2bff/in/terminology/define.xml \
  --term-audit terminology.xlsx \
  -obff individuals.json \
  --test -O