feat: standardize dashboard metric aggregation

[ash1shkumar]

📝 Description

This PR improves dashboard metric generation by introducing reusable aggregation helpers and standardizing metric derivation workflows across dashboard sections.

Previously, dashboard metrics, chart datasets, and insight summaries were derived through separate aggregation paths embedded directly within component logic. While functionally correct, this structure increased duplication and made future dashboard enhancements more difficult to maintain.

Changes Implemented

• Added reusable dashboard aggregation helpers
• Centralized chart data generation logic
• Centralized dashboard metric construction
• Standardized project insight derivation
• Reduced repeated aggregation patterns
• Improved separation between data preparation and UI rendering
• Simplified future dashboard metric expansion

Benefits

• Improved consistency across dashboard metrics
• Reduced duplication of aggregation logic
• Cleaner dashboard architecture
• Easier maintenance of analytical workflows
• Improved extensibility for future insights
• Better scalability for dashboard computations
• Stronger separation of concerns

🎯 Type of Change

• Refactoring
• Performance Improvement
• Maintainability Enhancement

✅ Testing

• Verified dashboard loads successfully
• Verified chart rendering remains unchanged
• Verified filter switching between week and month works correctly
• Verified dashboard statistics render correctly
• Verified project insight cards display expected values
• Verified chart data updates correctly when filters change
• Verified analytics section behavior remains unchanged
• Verified no UI regressions after aggregation refactoring
• Verified team member section remains functional
• Verified dashboard navigation and links continue to work correctly

Fixes #204

Expected Labels

level3 NSoC'26

[vercel]

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[github-actions]

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