- R034 _r034_ref_g1_required: when payer opts in (require_ref_g1_for_adjustments),
emit error if frequency_code is 7/8 and no REF*G1 segment appears in raw_segments.
CO Medicaid stays lenient in v1 (gate is False by default).
- R035 _r035_bht06_allowed: BHT06 transaction type code must be in cfg.allowed_bht06.
Skipped silently when transaction_type_code is None.
- Add transaction_type_code (str|None) to Envelope and ClaimOutput.
- parse_837: read BHT06 (seg[6]) in _build_envelope; mirror onto each ClaimOutput
via the existing model_copy(update={...}) call site.
- 9 new tests in test_validator.py: 5 R034 (incl. lenient no-op) + 4 R035.
213 passed, 1 skipped (prodfile corpus present-conditional).
Tyler