feat: implement dynamic client-side repository filtering for Contribu…

[Abhi666-max]

Summary

This PR implements dynamic client-side repository filtering for the ContributionGraph component. It replaces the old single-select dropdown with a modern, multi-select badge UI, allowing users to isolate specific codebases. The filtering happens entirely on the client side, ensuring instant chart updates without making heavy round-trips to the GitHub API.

Closes #388

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Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that changes existing behavior)
• 📝 Documentation update
• ♻️ Refactor / code cleanup (no functional change)
• ⚡ Performance improvement
• 🔒 Security fix
• 🧪 Tests only

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What Changed

• Replaced the native <select> dropdown in src/components/ContributionGraph.tsx with dynamic, multi-select Tailwind CSS badge buttons.
• Updated the state management from a single repo string to a selectedRepos array to support multiple selections.
• Implemented a useMemo hook (filteredData) to instantly filter the chart's dataset on the client side before passing it down to the Recharts components (BarChart, LineChart, AreaChart).

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How to Test

1. Navigate to the dashboard where the ContributionGraph is rendered.
2. Click on the various repository badges next to the timeframe selectors to toggle them on and off.
3. Observe the chart—it should update instantly to reflect only the data for the selected repositories without triggering a page reload or a new API request.

Expected result: The Recharts bars/lines instantly transition and scale smoothly based on the filtered local dataset.

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Screenshots / Recordings

Before	After
Native single-select <select> dropdown	Inline multi-select Tailwind toggle badges

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Checklist

• Linked the related issue above
• Self-reviewed my own diff
• No unnecessary console.log, debug code, or commented-out blocks
• npm run lint passes locally
• No TypeScript errors (npm run type-check)
• Added or updated tests where applicable
• Updated documentation / comments if behavior changed

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Accessibility (UI changes only)

• Keyboard navigation works correctly
• Color contrast meets WCAG AA standard
• ARIA labels / roles added where needed
• Tested on mobile / responsive layout

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Additional Context

The UI and state architecture for client-side filtering are fully implemented. The data bypass inside the useMemo hook is set up to receive the specific repository identifiers from the merged contribution dataset.

[github-actions]

GSSoC Label Checklist 🏷️

@Priyanshu-byte-coder — please apply the appropriate labels before merging:

Difficulty (pick one):

• level:beginner — 20 pts
• level:intermediate — 35 pts
• level:advanced — 55 pts
• level:critical — 80 pts

Quality (optional):

• quality:clean — ×1.2 multiplier
• quality:exceptional — ×1.5 multiplier

Validation (required to score):

• gssoc:approved — counts for points
• gssoc:invalid / gssoc:spam / gssoc:ai-slop — does not score

Type labels (type:*) are auto-detected from files and title. Review and adjust if needed.
Points formula: (difficulty × quality_multiplier) + type_bonus

[Abhi666-max]

Hi @Priyanshu-byte-coder,

I've successfully implemented the client-side repository filtering and replaced the old <select> dropdown with the new multi-select Tailwind badge buttons as requested in the issue!

All core checks (Build, Lint, Dependency Audit) are fully passing now. However, the E2E / Playwright smoke tests check is failing. Since the UI structure has intentionally changed, I suspect the existing smoke tests or visual snapshots might be out of sync with the new DOM.

Could you please take a look? Let me know if you'd like me to update any specific test files, or if you prefer to update the snapshots/test-locators from your end during the review!