fix(package-index): align validation with package manager config

[gbrogers]

Summary

• Updates the Runneth package-index validator to match the current package-manager contract: package-root package.json manifests, installPolicy, backend-github package sources, and non-semver version strings.
• Updates managed-sync fleet approval detection to account for installPolicy and updatePolicy changes.
• Refreshes the validation workflow comment so it describes the current catalog, package-index, and site jobs.

Validation

• node --test scripts/validate-runneth-package-index.mjs
• Temporary non-empty package-index fixture with backend-github source, package.json manifest, installPolicy, package_instruction, and non-semver version string

Notes

• node --test scripts/validate-catalog.mjs still fails on existing catalog data: runneth-classic is built but missing from catalog/excluded, and add-roles-permissions/install-config.json is missing changelog data.

[thedumsieffect]

what a great piece of code