Out of scope, learn cybersecurity. A simple concept such as users and permissions solves this problem.

Regardless of what technique you use, you need a deputy, you wouldn't ask an employee not to go into the vault, right? You would lock the vault. Well you can ask the employee not to go into the vault, and you can also ask codex not to use certain files, but if you need more certainty, you need to it outside.

The issue seems to be that people want to ask their agent to do everything, they want the agent to lock themselves out of some system, they want the agent to install itself, they want the agent to write their prompts so they don't have to write them. At some point there's some things YOU have to do, and you have to DO them.