GitHub review connector quota failure leaves required exact-head review blocked without retry guidance

Problem

The GitHub-hosted Codex reviewer can reject a requested security review with only:

You have reached your Codex usage limits for security reviews. Please try again later.

Example: https://github.com/autumngarage/touchstone/pull/827#issuecomment-5283708031 (2026-08-13). The PR is public and the review was requested against exact head e9780c11116c17b4ba5aa7c8767082fdf22394a4.

Impact

This repository requires PR-visible exact-head review before merge. A quota rejection therefore blocks delivery, but the response provides no retry-after time, quota window, observable quota state, or durable queued retry. Re-requesting blindly risks duplicate work and further quota consumption. The immediately preceding PR needed multiple review/fix rounds, which appears to have exhausted the quota during normal feedback handling.

Requested behavior

Please provide at least one actionable recovery signal:

• a concrete retry-after timestamp/duration,
• a machine-readable quota status, or
• automatic queuing/retry of the existing exact-head request when quota becomes available.

The review result should remain bound to the requested head so recovery does not require moving the commit or weakening the merge gate.

No repository file or test is named. Start by locating the GitHub review connector's quota-rejection handling and the exact-head request path, using the linked PR example for context. Done means an actionable retry signal or queued retry exists while preserving the requested commit head.