Add comprehensive test coverage for internal packages: - internal/config: 66.2% → 98.5% - internal/dns: 67.8% → 84.3% - internal/output: 48.8% → 89.1% - internal/traverse: 56.3% → 86.9% Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Co-authored-by: multica-agent <github@multica.ai>