The test now accepts both exit code 0 (no errors) and 1 (has errors)
since CI environments may have low disk space or missing tools that
trigger error-level diagnostic checks.
Add structured data builders and Rich renderers for version, info, and
diagnostics commands. Support --format rich/plain/json/yaml output parity
and --check flag for diagnostics (exits non-zero on errors).
Includes Behave scenarios, Robot smoke tests, ASV benchmarks, and updates
existing tests to match the new Rich panel output format.