feat(docs): add letter badges to objectives and improve card design

[jgeluk]

Changes

This PR adds stylized letter badges to the objectives page and improves the overall card design.

Features

• ✨ Letter badges: Replaced identical refresh icons with circular letter badges (A-M) for each objective
• 🎨 Improved design: Badges use gradient backgrounds matching the primary color scheme
• 📱 Dark mode support: Badges adapt to light/dark themes
• ✨ Hover effects: Badges scale and rotate slightly on hover

Improvements

• 🧹 Cleaner titles: Removed redundant letter prefixes from card titles (badge already shows the letter)
• 🔧 YAML fixes: Fixed frontmatter parsing issues by quoting titles with colons
• 📝 Consistency: Ensured all objective summaries are italicized
• 📋 Navigation: Updated sidebar to show lettered objectives alphabetically

Files Changed

• 13 objective markdown files (added letter prefixes to titles/headings)
• (replaced icons with badges, removed letter prefixes)
• (added letter prefixes to sidebar navigation)
• (added badge styling with hover effects)

Visual Changes

• Each objective card now displays a unique circular badge with its letter
• Card titles no longer repeat the letter (e.g., "Interoperability Achieved" instead of "A: Interoperability Achieved")
• Badges have gradient backgrounds and smooth hover animations