Remove plugins/, workspace-configs-templates/, org-templates/ dirs (now
in standalone repos). Add manifest.json listing all 33 repos and
scripts/clone-manifest.sh to clone them. Both Dockerfiles now use the
manifest script instead of 33 hardcoded git-clone lines.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
