de-gpt-ify

MEDIUM W012: Unverifiable external dependency detected (runtime URL that controls agent).

• Potentially malicious external URL detected (high risk: 0.90). The install instruction uses npx to fetch and install remote code from https://github.com/nangongwentian-fe/jay-skills, and that fetched repository (via the provided install.sh) writes rules into ~/.codex/AGENTS.md which directly control agent prompts/behavior, so this is a runtime external dependency that controls prompts.