feat: add Global Leaderboard & Ranking System dashboard

[saidai-bhuvanesh]

🚀 [Feature] Global Rankings & Achievements Dashboard

✨ Overview

This PR introduces an advanced Global Rankings & Achievements Dashboard for DevCard, bringing competitive developer intelligence, reputation tracking, contribution leaderboards, achievement systems, and realtime OSS ranking analytics into the platform ecosystem.

The implementation expands DevCard’s analytics infrastructure with modern leaderboard systems, animated reputation progression, contribution achievement tracking, and reusable enterprise-grade dashboard components powered by lightweight Svelte 5 rendering.

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🎯 Key Features

🏆 Global Developer Rankings

• Realtime contributor leaderboard system
• Dynamic developer score tracking
• Rank movement indicators
• OSS reputation ranking analytics
• Competitive contributor intelligence

💎 Reputation Tier System

• Diamond / Master / Gold tier progression
• Realtime reputation score visualization
• Tier milestone forecasting
• Animated progress ring system
• Developer reputation growth analytics

🎖️ Achievement Infrastructure

• Contribution milestone achievements
• Hackathon reward badges
• OSS streak progression tracking
• Locked/unlocked achievement states
• Gamified contribution ecosystem

📡 Live Contributor Feed

• Realtime contributor activity stream
• OSS milestone notifications
• PR merge activity intelligence
• Community event visibility system
• Live ecosystem updates

🕸️ Enterprise Dashboard Experience

• Glassmorphism-inspired UI system
• Responsive analytics layout
• Modular reusable dashboard widgets
• Interactive ranking systems
• Lightweight native rendering architecture

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🏗️ Components Added

Ranking Systems

• GlobalRankingsTable.svelte
• DeveloperLeaderboardCard.svelte
• RankingTrendIndicator.svelte

Reputation Analytics

• TierProgressCard.svelte
• ReputationRingChart.svelte
• GrowthMilestoneTracker.svelte

Achievement Systems

• AchievementGrid.svelte
• AchievementBadge.svelte
• MilestoneUnlockCard.svelte

Activity Intelligence

• TopContributorsFeed.svelte
• RealtimeActivityInsights.svelte

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⚡ Technical Improvements

Performance

• Lightweight SVG progress rendering
• Optimized reactive calculations
• Efficient leaderboard rendering system
• Reusable dashboard component architecture

Accessibility

• Keyboard-accessible ranking systems
• Semantic dashboard rendering
• ARIA-safe analytics interactions
• Improved focus-visible states

Scalability

• Reusable analytics infrastructure
• Modular achievement system architecture
• Shared leaderboard rendering utilities
• Expandable reputation framework

Security

• Safe text rendering patterns
• No unsafe HTML injection
• Strict reusable rendering components

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🧪 Validation

✅ Svelte 5 compatibility verified
✅ Responsive layouts tested
✅ Realtime ranking rendering validated
✅ Accessibility interactions verified
✅ No TypeScript compilation issues
✅ Frontend-only implementation confirmed
✅ No backend regressions introduced

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🔒 Architecture Notes

• Frontend-only implementation
• No database schema modifications
• No backend API changes
• No authentication flow changes
• Reusable enterprise dashboard architecture
• Low merge-conflict probability

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🚀 Impact

This PR transforms DevCard into a competitive AI-powered developer ecosystem with realtime contribution rankings, achievement intelligence, reputation progression systems, and gamified OSS engagement infrastructure optimized for future scalability and contributor retention.

[saidai-bhuvanesh]

Applied a complete frontend architecture hardening pass including reusable visualization extraction, accessibility improvements, security-safe rendering updates, performance optimizations, duplicate rendering cleanup, and reusable analytics infrastructure stabilization.