f932768e35
This improves detection accuracy: 1. Add name normalization for numbered design frame names (e.g., '12. Withdraw' → 'withdraw') 2. Add pages.json cross-validation to ensure no pages are missed 3. Add structure check using .pen node tree before visual comparison - detects missing blocks early 4. Add enforced checklist for correct difference counting - icon mismatch must be counted as moderate 5. Add examples for correct grading