v1.6.2 release: Marketing site design refinements

CHANGELOG Updates:
- Added v1.6.2 section with comprehensive design refinement details
- Updated version history table with v1.6.2 entry
- Documented all gradient updates (primary + success mix)
- Documented shadow weight reductions
- Documented automation icon simplifications
- Documented new Upcoming Features page
- Listed all 8 files changed in marketing site
- Added git commit references

Documentation Updates:
- Updated docs/INDEX.md version from 1.6.1 to 1.6.2

Version 1.6.2 Summary:
✅ Brand Color Consistency - All gradients use primary + success
✅ Shadow Refinements - Reduced from 2xl to md/lg for cleaner look
✅ Automation Icons - Simplified from colorful mix to consistent primary
✅ Upcoming Features Page - 362 lines, 3 phases, 10 features
✅ Marketing Pages - Home, Product, Pricing, Solutions, Partners, CaseStudies updated

Design Principles Applied:
- Brand consistency (matching logo colors)
- Visual hierarchy (reduced shadows)
- Clean & branded (simplified icons)
- Subtle & elegant (modern appearance)
- Content first (reduced decorative effects)

docs/INDEX.md

@@ -1,6 +1,6 @@
 # IGNY8 Technical Documentation
 
-**Version:** 1.6.1
+**Version:** 1.6.2
 **Last Updated:** January 8, 2026  
 **Purpose:** Complete technical reference for the IGNY8 AI content platform