J8k3
259b9740a7
Add EMV Build/Parse ARPC Data operations
- EMV Build ARPC Data: assembles ARPC preimage from named fields; Method 1 (Visa/Amex/Discover: ARQC+ARC, 10 bytes) and Method 2 (Mastercard: ARQC+CSU+optional PAD, 12-20 bytes); outputs hex (chainable into EMV Generate ARPC), JSON, or annotated
- EMV Parse ARPC Data: inverse; parses hex preimage back into named fields by method
- Shared lib EmvArpc.mjs with build/parse/format functions
- 6 new tests in Payment.mjs
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>