- Define Logger interface with Debug and Error methods
- Add NopLogger as default (no-op implementation)
- Add SetDefaultLogger/DefaultLogger for package-level config
- Add WithLogger method for per-command logger injection
- Log commands at DEBUG level before execution
- Log failures at ERROR level with error details
- Add comprehensive tests for logger functionality
Compatible with pkg/log.Logger and other structured loggers.
Closes#90
Co-Authored-By: Claude <noreply@anthropic.com>
