Refactor error field synchronization with helper methods

[trevorchaney]

This PR consolidates error field synchronization by adding error setting methods that ensures i.Err and i.werr are always kept in sync.

Changes

• Added 'initErrors' and 'seterrors' method to Info struct that takes an error pointer and updates both error fields
• Added nil pointer assertion with panic for fail-fast behavior on programming errors
• Replaced manual error field assignments throughout the codebase with calls to initErrors and setErrors

Benefits

• Eliminates manual error synchronization patterns that could lead to inconsistencies
• Provides fail-fast behavior for programming errors (nil pointer detection)
• Improves code maintainability and reduces duplication
• All existing functionality preserved with comprehensive test coverage

Testing

• All unit tests pass
• Race detection tests pass (verified with WSL)
• Performance benchmarks show no regressions
• Comprehensive test suite validates no breaking changes

[lainio]

Thank you! I like this. I added a comment about the name of the function. Let's start the discussion 😃

[lainio]

Works for me, and the test matrix is green. I also ran make inline_hander for checks.