* feat: add Codex plugin packaging (single-plugin, metadata-only)
Adds .codex-plugin/plugin.json with a skills array listing all public
skills, plus .agents/plugins/marketplace.json for one-command install:
codex plugin marketplace add magnus919/agent-skills
codex plugin install magnus919
Same pattern as mattpocock/skills — one plugin, explicit skill paths,
no dist/, no curation, no duplication. Bundle-internal helpers excluded
by the shared glob. CI check mode fails if the manifest drifts.
Closes#79
AI-assisted: yes (Jasper/Hermes Agent)
* chore: trigger CI
* chore: regenerate Codex plugin manifest to include neckbeard bundle
