Flags the SY/B disambiguation change and the field-vs-property merge
landmine (raises AttributeError at first EpcPropertyData instantiation,
not at import; git merges silently) for the feature/bill-derivation
reviewer, with the recommended reconciliation and the strict-xfail
tripwire they own.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
