Add Bloch sphere tab with qubit selection dropdown

[kanishka1804]

🔗 Related Issue

• Closes #

🎯 Rationale

Explain the reasoning behind this change:

This PR adds an interactive Bloch sphere tab that lets users select qubits from a dropdown.
This feature visually enhances the quantum state representation and fills a missing functionality.

📝 Summary of Changes

Provide a clear overview of what this PR includes:

• Added BlochSphere.jsx component
• Updated Navbar.jsx to include tab navigation
• Added dropdown to select qubits
• Modified App.jsx to integrate the new tab

🔧 Technical Details

✅ Testing

Describe how these changes have been tested:

• Manually tested UI interactions locally with React dev server
• Verified no console errors and expected visual results
• Existing unit tests still pass

Test Coverage

• [✅] Unit tests added/updated
• [✅] Integration tests added/updated
• [✅] Manual testing completed
• [✅] All existing tests pass

Test Details

📚 Documentation

Documentation changes and updates:

• [✅] Code comments added/updated
• [✅] README updated (if needed)
• API documentation updated (if needed)
• Migration guide provided (for breaking changes)

🔄 Breaking Changes

• This PR contains breaking changes
• Migration guide provided
• Version updated appropriately

🎨 User-Facing Changes

Frontend Changes

• [✅] UI components modified
• [✅] New user interactions added
• Styling/theme changes

Backend/API Changes

• New endpoints added
• Existing endpoints modified
• Response format changes

📋 Checklist

Code Quality

• [✅] Code follows project style guidelines
• [✅] Self-review completed
• [✅] No console.log or debug statements left
• [✅] Error handling implemented appropriately

Review Readiness

• [✅] PR title is descriptive and follows conventions
• [✅] PR description is complete and accurate
• [✅] Commits are atomic and well-documented
• [✅] Branch is up to date with target branch

Security & Performance

• [✅] No sensitive information exposed
• [✅] Performance impact considered
• [✅] Security implications reviewed

🚀 Deployment Notes

Open in Integrated Terminal from visualizer

• npm install
• npm install three
• npm run dev

📸 Screenshots/Demo

🙏 Reviewer Notes

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