Performance & Accessibility improvements

[jamespepper81]

Review and improve key metrics related to performance and accessibility across the BitSleuth Website:

• Audit Core Web Vitals (Largest Contentful Paint, Cumulative Layout Shift, etc.)
• Address any accessibility issues (color contrast, semantic structure, ARIA roles)
• Optimize Next.js 15 build for initial page load and subsequent navigations
• Ensure best practices for TypeScript and CSS impacting performance

Deliverables:

• Report of current metrics and issues
• List of prioritized fixes and enhancements
• Implemented fixes with references to metrics improvements

Milestone: Performance & Accessibility