WIP: add pytest params.env validation test

Rewrite of ci/check-params-env.sh as pytest with structured output.
Uses skopeo to validate image labels, commit IDs, repo names, and sizes.
Expected metadata extracted from shell script case statement to YAML.

Known issues:
- Some ODH entries missing from expected-image-metadata.yaml
- Repo name URL parsing needs fix for @sha256: refs
- Commit ID lookup logic needs correction

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jiridanek