feat(seo-review): add Technical SEO checklist with 3 new checks

- Add Technical SEO Checklist section (3 points):
  - Single H1 per page
  - URL slug contains keyword
  - No orphan pages
- Update scoring system from 27 to 30 total points
- Add Technical SEO Issues table with common fixes
- Update report template with Technical SEO analysis section
- Update CLAUDE.md with new scoring reference