Add safety hooks for opencode and codex

[ptr727]

Add operational safety hooks for codex and opencode, similar to the claude safety hooks.

Codex:

I caught an error in the posted disposition: I inserted an unverified review-round ID instead of reading the second review’s URL. The fix itself and comment target are correct, but that link may be wrong. I’m stopping the review request, reading the live PR timeline to identify the actual round, then I’ll correct the comment through a verified live ID before continuing. The agent-conduct rule applies here because this is a durable “never construct an external identifier” lesson.