Parse an X12 EDI document (850, 856, 810, 855, 997 and others) into structured JSON.

Reads a raw ASC X12 interchange and returns it as JSON: delimiters taken from the ISA header, the ISA/GS/ST envelope decoded, every segment split into named elements, and a document-specific summary - purchase order lines for an 850, the HL shipment hierarchy and SSCCs for an 856, invoice totals for an 810. EDI is positional and delimiter-sensitive, and unreadable without a spec table; reading it by inspection produces confident nonsense, which is why this is a tool rather than a prompt.