grepxcel 0.4.1

Fixed

• not-null / not-empty round-trip fidelity — FieldDef now stores required_token
  (the original parser token) so the web wizard no longer silently rewrites not-empty fields
  as not-null when a pattern is saved after preload.
• Single source of truth for token sets — VALID_MODE_TOKENS / VALID_CONSTRAINT_TOKENS
  exported from pattern_parser.py and imported by wizard_core.py; local duplicate
  frozensets in _col_a_extra_to_parts eliminated.
• var:(default) guard — the pattern writer now strips (default) from var: col-A
  cells, symmetric with the existing lbl:(default) guard.
• Stale lbl:(default) fixture — 01_simple_invoice_data_pattern-from-web.csv had
  8 rows written with the old lbl:(default) syntax that PatternParser rejects; fixed to
  lbl:.
• Silent test skip — test_pattern_tester.py referenced a non-existent fixture filename,
  causing 10 tests to silently skip; corrected.

Improved

• AI-debug logging in web-wizard session log — three new structured event types make
  session logs machine-readable for bug analysis and architecture tracing:
  • PRELOAD_FIELD — one entry per cell loaded from a pattern file (role, name, type,
    match pattern, col_a_extra modifiers).
  • SCHEMA_SUMMARY — emitted immediately before each SAVE; reports lbl=N var=N total=N
    and a modifier distribution (not-null×3 trim-whitespace×1 …).
  • Session log header updated to document all event types.
• Unrecognized-token warning — _col_a_extra_to_parts now emits a logging.WARNING
  when it encounters tokens not in the parser's valid sets, naming the offending tokens and
  the complete valid token lists.