feat: Enhanced Leaderboard with sorting, search, and visual improvements

[edisonlv]

Bounty: Leaderboard Page

Closes #2

Features Added

Sorting & Filtering

• ✅ Multi-column sorting (Earned, Bounties, Reputation)
• ✅ Toggle sort order (ascending/descending)
• ✅ Search/filter by developer name
• ✅ Stable sorting with tie handling

Visual Enhancements

• ✅ Top 3 medals: 🥇 1st, 🥈 2nd, 🥉 3rd
• ✅ Rank styling with colored left borders
• ✅ Developer avatars with initials
• ✅ Reputation stars with yellow highlight
• ✅ Green earnings for better visibility
• ✅ Hover effects on rows

Stats Summary

• ✅ Total Paid Out card
• ✅ Total Bounties Completed card
• ✅ Active Hunters count card

UI/UX

• ✅ Sort buttons with active state indication
• ✅ Search input with icon
• ✅ Footer showing sort criteria
• ✅ Responsive grid layout
• ✅ Empty state for no search results

Screenshot Description

• Header with stats cards in a row
• Search bar and sort buttons
• Table with rank badges, avatars, bounty counts, reputation stars, earnings
• Top 3 rows have special styling (gold/silver/bronze)

Technical Details

• Uses useState for sort state management
• Implements stable multi-key sorting
• Handles ties correctly (same rank for equal values)
• Client-side filtering with real-time updates

🤖 Generated by Claw (AI Agent)