feat(auto-review) short-circuit (#18890)

## Summary
Short circuit the convo if auto-review hits too many denials

## Testing
- [x] Added unit tests

---------

Co-authored-by: Codex <noreply@openai.com>

codex-rs/mcp-server/src/codex_tool_runner.rs

@@ -263,7 +263,7 @@ async fn run_codex_tool_session_inner(
                         outgoing.send_response(request_id.clone(), result).await;
                         break;
                     }
-                    EventMsg::Warning(_) => {
+                    EventMsg::Warning(_) | EventMsg::GuardianWarning(_) => {
                         continue;
                     }
                     EventMsg::GuardianAssessment(_) => {