update_version rewrote plugins/ecc/.codex-plugin/plugin.json on disk, but
CODEX_MARKETPLACE_PLUGIN_JSON was missing from the git add list, so the bump
was never committed. The tag then carried a 2.0.0 manifest and
plugin-manifest.test.js failed the release in CI.
Also commits the 2.1.0 value the previous run left uncommitted.
Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0149VwNuynam6rvEfcMmiHHa