Add codex-adapter.sh, replace inline transport detection

Document codex exec stdin hang workaround in troubleshooting

Prefer Codex plugin transport, add /codex:review verification step

Add host check and Codex UI metadata

Fix codex exec invocation and add safety patterns

Rename repo from claude-skill-codex-implement to skill-codex-implement

Restructure for plugin convention and add README

Improve skill based on best practices review

Initial commit: codex-implement skill