Check Plugin Version

Verify the installed compound-engineering plugin version matches the upstream plugin.json on main, and recommend the update command if it doesn't. Claude Code only.

The upstream version comes from plugins/compound-engineering/.claude-plugin/plugin.json on main rather than the latest GitHub release tag, because the marketplace installs plugin contents from main HEAD. Comparing against release tags false-positives whenever main is ahead of the last tag (the normal state between releases).

Step 1: Probe versions

Run these three scripts in parallel via the Bash tool. Each prints a single line of output; capture the values for the decision logic below. Use ${CLAUDE_SKILL_DIR} so the path resolves correctly in both claude --plugin-dir local-development sessions and standard marketplace-cached installs.