$translate R4 endpoint uses R5 output field name (relationship vs equivalence)

[jmandel]

Summary

The R4 $translate endpoint returns relationship (an R5 field name) instead of equivalence (the R4 field name) in its match output.

Root cause

In tx/workers/translate.js line ~283, the code outputs:

matchParts.push({ name: 'relationship', valueCode: map.relationship });

But on the R4 endpoint, this should be:

matchParts.push({ name: 'equivalence', valueCode: ... });

Repro

curl -s -H 'Content-Type: application/fhir+json' -H 'Accept: application/fhir+json' \
  -X POST 'https://tx-dev.fhir.org/r4/ConceptMap/$translate' \
  -d '{"resourceType":"Parameters","parameter":[{"name":"sourceCode","valueCode":"active"},{"name":"sourceSystem","valueUri":"http://example.org/cs1"},{"name":"targetSystem","valueUri":"http://example.org/cs2"},{"name":"tx-resource","resource":{"resourceType":"ConceptMap","url":"http://example.org/cm-test","status":"active","group":[{"source":"http://example.org/cs1","target":"http://example.org/cs2","element":[{"code":"active","target":[{"code":"A","equivalence":"equivalent"}]}]}]}}]}'

Prod match part: {"name": "equivalence", "valueCode": "Equivalent"}
Dev match part: {"name": "relationship", "valueCode": "equivalent"}

Notes

This also affects the value — prod capitalizes (Equivalent, Wider) while dev uses lowercase (equivalent). The R4 spec uses lowercase values.