4fd8ece170
- STYLE_user renamed to STYLE_H1K0 in VOCAB (author's personal tag) - Style field now accepts any [A-Za-z][A-Za-z0-9_]* identifier in .chord files - Unknown styles fall back to STYLE_other at tokenization time with a log warning - Test fixtures updated to style: other; drop closed _VALID_STYLES frozenset - Spec bumped to v2.1: documents open style field, fallback behaviour, and §5.7 guide on registering a new style token Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>