Persist Guardian V2 risk scores without restoring them (#40884)

## What changed

- Append accepted Guardian V2 classification results to rollout history for non-ephemeral threads.
- Keep resumed and forked threads from restoring a persisted score into active Guardian state.

## Testing

- Verify that asynchronous scoring records the resulting `SecurityRiskScore` rollout item.
- Seed resume and fork tests with a persisted score and verify that approvals ignore it.

GitOrigin-RevId: 40d63a2ea7e7cf6398402c6aed7d5e5727dc9d68

codex-rs/ext/guardian-v2/src/async_scorer/extension.rs

@@ -29,6 +29,7 @@ use codex_extension_api::ToolName;
 use codex_extension_api::ToolPayload;
 use codex_extension_api::ToolStartInput;
 use codex_features::Feature;
+use codex_history::RolloutItem;
 use codex_login::AgentIdentityAuthPolicy;
 use codex_login::AuthManager;
 use codex_model_provider::create_model_provider;
@@ -796,6 +797,19 @@ impl GuardianV2Extension {
                     .latest_scored_tool_call
                     .fetch_max(tool_call_index, Ordering::Release);
                 classification_finished_at = Some(Instant::now());
+                if !config.ephemeral
+                    && let Err(error) = thread
+                        .append_rollout_items(&[RolloutItem::SecurityRiskScore(score)])
+                        .await
+                {
+                    tracing::warn!(
+                        %thread_id,
+                        %turn_id,
+                        %call_id,
+                        %error,
+                        "failed to persist Guardian V2 classification result"
+                    );
+                }
                 Ok("success")
             }
             .await;

codex-rs/ext/guardian-v2/src/async_scorer/extension_tests.rs

@@ -22,6 +22,7 @@ use codex_extension_api::ToolName;
 use codex_extension_api::ToolPayload;
 use codex_extension_api::ToolStartInput;
 use codex_features::Feature;
+use codex_history::RolloutItem;
 use codex_login::AuthManager;
 use codex_login::CodexAuth;
 use codex_login::ExternalAuth;
@@ -1726,6 +1727,27 @@ async fn contributor_samples_tool_calls_with_the_existing_luna_pool() -> Result<
         }
     );
     assert!(score.sampled_at.is_some());
+    test.codex.ensure_rollout_materialized().await;
+    let persisted_score = tokio::time::timeout(Duration::from_secs(5), async {
+        loop {
+            if let Some(persisted_score) = test
+                .codex
+                .load_history(/*include_archived*/ false)
+                .await?
+                .items
+                .into_iter()
+                .find_map(|item| match item {
+                    RolloutItem::SecurityRiskScore(score) => Some(score),
+                    _ => None,
+                })
+            {
+                return Ok::<_, anyhow::Error>(persisted_score);
+            }
+            tokio::task::yield_now().await;
+        }
+    })
+    .await??;
+    assert_eq!(&persisted_score, score.as_ref());
     assert_eq!(
         registry
             .fast_approval_decision(