feat(output): add result display method to Output class

[ChristopherJHart]

The Output class needs a result() method for displaying structured program output (e.g., test results summaries, formatted tables).

Requirements

• Add Output.result(data: Any) -> None method
• Support rendering Rich tables, formatted summaries, and structured data
• Integrate with the existing reporting pipeline for console-friendly output

Use cases

• Displaying a pass/fail summary table after a test run
• Showing phase-level aggregate results
• Rendering validation output

References

docs/08-output-logging-design.md — "Output Class Interface" section.