Validate package integration and final testing

[github-actions]

Package Integration and Final Testing

Description

Ensure the complete arithmetic package works correctly as an integrated whole and meets all specification requirements.

Acceptance Criteria

• Verify add function can be imported correctly: from arithmetic import add
• Confirm all unit tests pass
• Test package installation in clean environment
• Validate that README examples work correctly
• Ensure package structure follows Python best practices
• Run integration tests to verify end-to-end functionality

Dependencies

Depends on #2, #3, #4

Integration Tests Required

• Test importing the package and using the add function
• Verify examples from README work correctly
• Test package installation from source
• Run full test suite and confirm 100% pass rate
• Test with different Python versions (if specified)