Add test coverage reporting and achieve 80%+ coverage

[sivchari]

📋 Description

Add comprehensive test coverage reporting and achieve the 80%+ coverage requirement for awesome-go submission.

🎯 Goals

• Set up automated test coverage reporting
• Add coverage badge to README
• Achieve minimum 80% test coverage (90% for data-related packages)
• Integrate with CI/CD pipeline

📝 Tasks

1. Coverage Setup

   • Add coverage profile generation to test commands
   • Set up codecov.io or coveralls.io integration
   • Add coverage badge to README

2. Improve Test Coverage

   • Analyze current coverage with go test -cover ./...
   • Identify untested code paths
   • Add missing unit tests for validators
   • Add missing tests for analyzer code
   • Add integration tests where needed

3. CI Integration

   • Update GitHub Actions to generate coverage reports
   • Upload coverage reports automatically
   • Fail CI if coverage drops below 80%

📊 Current Status

Need to measure current coverage baseline and identify gaps.

🔗 References

• awesome-go requirements: Test coverage ≥ 80% (≥ 90% for data packages)
• codecov.io: https://codecov.io/
• coveralls.io: https://coveralls.io/

✅ Acceptance Criteria

• Coverage badge visible in README
• Overall test coverage ≥ 80%
• Data-related packages coverage ≥ 90%
• Coverage reports generated on every PR
• Historical coverage tracking enabled