feat(http): http server for collaboration distance, erdos number and existence check

[liamjdavis]

Description

Full e2e http server supporting collaboration distance, erdos number calculation and existence check.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Changes Made

• HTTP Server
• Wrapper over HelixDB for HTTP calls
• Rate limiter for high traffic

Testing

• All existing tests pass
• Added new tests for the changes
• Coverage remains ≥80%
• Manual testing performed

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings or errors
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Related Issues

N/A

Screenshots (if applicable)

N/A

Additional Notes

N/A

[liamjdavis]

LGTM!