Add experimental Codex PR review guidance docs

[anth-volk]

Fixes #796

Summary

• add repo-native Codex review instruction files
• define a standardized priority and confidence rubric
• add focused review segments for general review, staged PRs, and testing

Notes

• This setup is experimental and may require bolstering, modification, and/or removal depending on token usage and effectiveness.
• This setup only guides review and recommendations. It does not modify production code, tests, runtime behavior, or CI behavior.

[anth-volk]

@codex review

[anth-volk]

@codex[agent] review

[Codex]

@anth-volk Unfortunately I hit an unexpected error while processing your comment. I've automatically reported this to GitHub.

You can ask me to try again later by mentioning me in a new comment.

If you want to contact GitHub about this error, please mention the following identifier so they can better serve you: 91bd2cea-f301-4cca-a389-c54cbebe850c

Sorry for the inconvenience!

[Codex]

@anth-volk Unfortunately I hit an unexpected error while processing your comment. I've automatically reported this to GitHub.

You can ask me to try again later by mentioning me in a new comment.

If you want to contact GitHub about this error, please mention the following identifier so they can better serve you: 91bd2cea-f301-4cca-a389-c54cbebe850c

Sorry for the inconvenience!

[Codex]

@anth-volk Unfortunately I hit an unexpected error while processing your comment. I've automatically reported this to GitHub.

You can ask me to try again later by mentioning me in a new comment.

If you want to contact GitHub about this error, please mention the following identifier so they can better serve you: 91bd2cea-f301-4cca-a389-c54cbebe850c

Sorry for the inconvenience!

[Codex]

@anth-volk Unfortunately I hit an unexpected error while processing your comment. I've automatically reported this to GitHub.

You can ask me to try again later by mentioning me in a new comment.

If you want to contact GitHub about this error, please mention the following identifier so they can better serve you: 91bd2cea-f301-4cca-a389-c54cbebe850c

Sorry for the inconvenience!

[Codex]

@anth-volk Unfortunately I hit an unexpected error while processing your comment. I've automatically reported this to GitHub.

You can ask me to try again later by mentioning me in a new comment.

If you want to contact GitHub about this error, please mention the following identifier so they can better serve you: 91bd2cea-f301-4cca-a389-c54cbebe850c

Sorry for the inconvenience!

[Codex]

@anth-volk Unfortunately I hit an unexpected error while processing your comment. I've automatically reported this to GitHub.

You can ask me to try again later by mentioning me in a new comment.

If you want to contact GitHub about this error, please mention the following identifier so they can better serve you: 91bd2cea-f301-4cca-a389-c54cbebe850c

Sorry for the inconvenience!

[anth-volk]

Putting in draft. Will retry when back. May just be spurious codex bug.