Claude Code <-> Codex CLI plugin parity

Port a Claude Code plugin to the OpenAI Codex CLI (or vice versa), and understand where the two plugin systems are identical vs where they diverge. Use when: (1) you have a Claude Code plugin (.claude-plugin/plugin.json + marketplace.json + hooks/hooks.json) and want it to also work under Codex CLI, (2) you are writing a .codex-plugin/plugin.json and wonder if you can reuse the existing hooks.json, (3) a ported plugin installs under Codex but its hooks misbehave or do nothing, (4) you need to confirm which plugin-root env vars a hook sees under Codex, (5) you need to know whether "submit to the official marketplace" has a Codex equivalent. Covers the manifest/marketplace …