Package errors provides a modern, lightweight alternative to pkg/errors, capturing a single stack trace at error creation time and preserving it through all wraps. It avoids redundant stack traces while maintaining compatibility with Go 1.13+ errors.Is / errors.As / errors.Unwrap. The API includes `New`, `Wrap`, `Errorf`, `WithStack`, and `Join`, offering familiar ergonomics without the noise of `WithMessage` or similar. The *Error type also implements slog.LogValuer for structured logging. Example_slogStructuredLogging demonstrates how to use slog for structured logging