v0.3.0 — Architecture refactor milestone

- Unified 837 P/I/D into single Edi837 struct with subtype enum
- HL parent-child tree: claims nested under subscriber/patient
- Shared ISA/GS/GE/IEA envelope structs across transaction types
- Consolidated main.rs routing (440 → 261 lines)
- Deduplicated 834 loop2100b-h into generic module
- Removed dead_code attrs, glob imports, review artifacts
- 257 tests, all 12 demo files round-trip verified
- Net -1,837 lines across 98 files

v0.2.0 — Production-safe hardening milestone

15 issues resolved from principal engineer code review:
- 998 panic paths eliminated (C1)
- Output corruption fixed (C2, H6)
- Envelope validation added (H5)
- 172 unnecessary clones removed (C5)
- 90 false-match segment finds fixed (H1+H2)
- Numeric field validation added (H4)
- 253 tests, all 12 transaction types round-trip verified

v0.1.0 - EDI Parser CLI

Healthcare X12 EDI parser supporting 12 transaction sets:
835, 999, 270, 271, 276, 277, 278, 837P, 837I, 837D, 820, 834

Features:
- Bidirectional EDI <-> JSON conversion
- Auto-detection of transaction set type
- Custom delimiter support (ISA segment detection)
- 238 unit tests passing
- Round-trip verified for all transaction sets