FInalising landing page

[LuminaEnvision]

Changes

• ✅ Added /litepaper page with full Version 3.0 content
• ✅ Added /tokenomics and /docs placeholder pages
• ✅ Updated navigation to separate internal/external links (internal links use green accent, external use yellow)
• ✅ Added back buttons to all new pages
• ✅ Updated litepaper content with token details ($bDCU, $cDCU)
• ✅ Reduced spacing in roadmap and community impact sections
• ✅ Centered community impact heading and description

Design

• Consistent with existing site branding (dark background, green/yellow accents)
• Responsive design for mobile and desktop
• Uses Bebas Neue for headings, Geist Sans for body text
• Clean typography and spacing

All pages are fully styled and ready for use.