Applies the same shared-field sync logic to the two marketplace.json
files that we already applied to plugin.json: name, owner.name,
description, version, and the full plugin catalog (name, source,
description per entry) must match across .claude-plugin/ and
.github/plugin/ manifests.
Fixes .github/plugin/marketplace.json to use the canonical Copilot
schema (description and version nested under metadata) rather than
a copy of Claude's top-level format. Adds owner field to both files.
Validate.sh handles the structural divergence by extracting values
from either location before comparing.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>