chore: reduce catalog contribution friction

[DevOpsAIguru123]

Summary

• Add a source-type dropdown so contributors can disclose official, community, documentation, or unknown provenance
• Replace the official-vendor-only required checkbox with a broader provenance disclosure
• Add a trust and maintenance signals field for security/privacy docs, release activity, maintainers, adoption, and tracing/eval evidence
• Add an explicit no-secrets checklist item

Validation

• python3 scripts/validate_repos_yaml.py
• /Users/tuximac/projects/awesome-agentic-devops/.venv/bin/python -m pytest -q