LOINC filter parameter ignored (returns all properties)

[jmandel]

Bug

When requesting specific properties via the property parameter for LOINC codes, the filter is ignored and all 25+ properties are returned. SNOMED property filtering works correctly.

Repro

# Request only COMPONENT — returns ALL 25+ properties
curl -s 'https://tx-dev.fhir.org/r4/CodeSystem/$lookup?system=http://loinc.org&code=1963-8&property=COMPONENT' \
  -H 'Accept: application/fhir+json' | jq '[.parameter[] | select(.name=="property")] | length'
# Returns: 25 (should be 1)

# SNOMED filter works correctly:
curl -s 'https://tx-dev.fhir.org/r4/CodeSystem/$lookup?system=http://snomed.info/sct&code=22298006&property=inactive' \
  -H 'Accept: application/fhir+json' | jq '[.parameter[] | select(.name=="property")] | length'
# Returns: 1 (correct)

Reproduces on both servers.

Spec reference

R4 section 6.4.18: property (IN, 0..*, code) — the server should return only the requested properties.