iomgaa
271d1682c9
feat(question_gen): add lightweight 4-gate quality check
Implement 4 concurrent LLM-based quality gates for generated questions:
- key_verify: validates answer evidence in source material
- blind_answer: rejects questions answerable without video context
- multi_true: detects ambiguous multi-correct options
- leak_test: per-family shortcut detection (5 probe templates)
Includes run_gates orchestrator with verbatim_ratio short-circuit,
JSON response parsing with fallback, and 9 unit tests (all passing).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>