fix: subtype resolver + comprehensive matching program test
Fix 4 remaining defects found by adversarial testing:
1. MT03 N:1 → subtype corrected to N:1 (key suffix -M/-T heuristic)
2. MT32 混合 → subtype added (項目チェック programs with WS-PREV-KEY)
3. MT33 混合异键 → WS-ALT-KEY detection → 混合(异键)
4. MT18/MT19 → subtype M:N (correct: static cannot distinguish M:N→M vs M:N→N)
Also expand subtype resolver scope: now also processes 項目チェック
classified programs with matching-like characteristics (WS-PREV-KEY),
not just マッチング.
New test: test_matching_programs.py — 10 parametrized tests covering
all 4 dimensions (category, subtype, branches, files) for every
matching program. Known limitation documented: MT18 vs MT19
requires runtime data for M:N→M vs M:N→N distinction.
Regression: 755 passed (10 new, 0 failures).
NB-076
a5939e6722