Added CHANGELOG entry for CLI extension test suite. Added Brent Edwards
to CONTRIBUTORS.md. Replaced broad except Exception with specific
ValidationError catch in benchmark. Moved import json to module
top-level in robot helper script.
ISSUES CLOSED: #326
Added comprehensive test coverage for CLI extension features from #325:
- Behave scenarios for automation_profile resolution, invariant ordering,
and actor override error cases
- Output snapshot assertions for JSON/YAML/table formats
- Robot integration test for action show with optional actors/invariants
- ASV benchmark for extended CLI scenario runtime baseline
- Updated testing.md with CLI extension test fixture documentation
ISSUES CLOSED: #326
brent.edwards
freemo