GHSA-8gmq-j984-vp4r: 9router: Unauthenticated LLM proxy access via /codex rewrite authorization bypass

## Summary 9router is a software that provides an LLM proxy (a middleman service that connects to AI providers like OpenAI). It's supposed to require an API key (a secret credential) for access, but there's a bypass vulnerability: requests sent to `/codex/*` are secretly rewritten to `/api/v1/responses` by the server configuration, and since the authorization check (middleware, a security layer that runs before the main code) only protects specific paths and doesn't include `/codex`, unauthenti