Rename approvals reviewer variant to auto-review (#19056)

## Why

`approvals_reviewer` now uses `auto_review` as the canonical config/API
value after #18504, but the Rust enum variant and nearby helper/test
names still used `GuardianSubagent` / guardian approval wording. That
made follow-up code and reviews confusing even though the external value
had already moved to Auto-review.

## What changed

- Renamed `ApprovalsReviewer::GuardianSubagent` to
`ApprovalsReviewer::AutoReview`.
- Updated protocol, app-server, config, core, TUI, exec, and analytics
test callsites.
- Renamed nearby helper/test names from guardian approval wording to
Auto-review wording where they refer to the approvals reviewer mode.
- Preserved wire compatibility:
  - `auto_review` remains the canonical serialized value.
  - `guardian_subagent` remains accepted as a legacy alias.

This intentionally does not rename the `[features].guardian_approval`
key, `Feature::GuardianApproval`, `core/src/guardian`, analytics event
names, or app-server Guardian review event types.

## Verification

- `cargo test -p codex-protocol
approvals_reviewer_serializes_auto_review_and_accepts_legacy_guardian_subagent`
- `cargo test -p codex-app-server-protocol
approvals_reviewer_serializes_auto_review_and_accepts_legacy_guardian_subagent`
- `cargo test -p codex-config approvals_reviewer`
- `cargo test -p codex-tui update_feature_flags`
- `cargo test -p codex-core permissions_instructions`
- `cargo test -p codex-tui permissions_selection`

codex-rs/core/src/codex_delegate_tests.rs

@@ -251,7 +251,7 @@ async fn handle_exec_approval_uses_call_id_for_guardian_review_and_approval_id_f
         crate::session::tests::make_session_and_context_with_rx().await;
     let mut parent_ctx = Arc::try_unwrap(parent_ctx).expect("single turn context ref");
     let mut config = (*parent_ctx.config).clone();
-    config.approvals_reviewer = ApprovalsReviewer::GuardianSubagent;
+    config.approvals_reviewer = ApprovalsReviewer::AutoReview;
     parent_ctx.config = Arc::new(config);
     parent_ctx
         .approval_policy
@@ -363,7 +363,7 @@ async fn delegated_mcp_guardian_abort_returns_synthetic_decline_answer() {
         crate::session::tests::make_session_and_context_with_rx().await;
     let mut parent_ctx = Arc::try_unwrap(parent_ctx).expect("single turn context ref");
     let mut config = (*parent_ctx.config).clone();
-    config.approvals_reviewer = ApprovalsReviewer::GuardianSubagent;
+    config.approvals_reviewer = ApprovalsReviewer::AutoReview;
     parent_ctx.config = Arc::new(config);
     parent_ctx
         .approval_policy

codex-rs/core/src/config/config_tests.rs

@@ -6741,10 +6741,7 @@ approvals_reviewer = "guardian_subagent"
         .build()
         .await?;
 
-    assert_eq!(
-        config.approvals_reviewer,
-        ApprovalsReviewer::GuardianSubagent
-    );
+    assert_eq!(config.approvals_reviewer, ApprovalsReviewer::AutoReview);
     Ok(())
 }
 
@@ -6757,17 +6754,14 @@ async fn requirements_disallowing_default_approvals_reviewer_falls_back_to_requi
         .codex_home(codex_home.path().to_path_buf())
         .cloud_requirements(CloudRequirementsLoader::new(async {
             Ok(Some(crate::config_loader::ConfigRequirementsToml {
-                allowed_approvals_reviewers: Some(vec![ApprovalsReviewer::GuardianSubagent]),
+                allowed_approvals_reviewers: Some(vec![ApprovalsReviewer::AutoReview]),
                 ..Default::default()
             }))
         }))
         .build()
         .await?;
 
-    assert_eq!(
-        config.approvals_reviewer,
-        ApprovalsReviewer::GuardianSubagent
-    );
+    assert_eq!(config.approvals_reviewer, ApprovalsReviewer::AutoReview);
     Ok(())
 }
 
@@ -6786,17 +6780,14 @@ async fn root_approvals_reviewer_falls_back_when_disallowed_by_requirements() ->
         .fallback_cwd(Some(codex_home.path().to_path_buf()))
         .cloud_requirements(CloudRequirementsLoader::new(async {
             Ok(Some(crate::config_loader::ConfigRequirementsToml {
-                allowed_approvals_reviewers: Some(vec![ApprovalsReviewer::GuardianSubagent]),
+                allowed_approvals_reviewers: Some(vec![ApprovalsReviewer::AutoReview]),
                 ..Default::default()
             }))
         }))
         .build()
         .await?;
 
-    assert_eq!(
-        config.approvals_reviewer,
-        ApprovalsReviewer::GuardianSubagent
-    );
+    assert_eq!(config.approvals_reviewer, ApprovalsReviewer::AutoReview);
     assert!(
         config.startup_warnings.iter().any(|warning| {
             warning
@@ -6826,17 +6817,14 @@ approvals_reviewer = "user"
         .fallback_cwd(Some(codex_home.path().to_path_buf()))
         .cloud_requirements(CloudRequirementsLoader::new(async {
             Ok(Some(crate::config_loader::ConfigRequirementsToml {
-                allowed_approvals_reviewers: Some(vec![ApprovalsReviewer::GuardianSubagent]),
+                allowed_approvals_reviewers: Some(vec![ApprovalsReviewer::AutoReview]),
                 ..Default::default()
             }))
         }))
         .build()
         .await?;
 
-    assert_eq!(
-        config.approvals_reviewer,
-        ApprovalsReviewer::GuardianSubagent
-    );
+    assert_eq!(config.approvals_reviewer, ApprovalsReviewer::AutoReview);
     Ok(())
 }
 
@@ -6857,7 +6845,7 @@ async fn approvals_reviewer_preserves_valid_user_choice_when_allowed_by_requirem
             Ok(Some(crate::config_loader::ConfigRequirementsToml {
                 allowed_approvals_reviewers: Some(vec![
                     ApprovalsReviewer::User,
-                    ApprovalsReviewer::GuardianSubagent,
+                    ApprovalsReviewer::AutoReview,
                 ]),
                 ..Default::default()
             }))
@@ -6865,10 +6853,7 @@ async fn approvals_reviewer_preserves_valid_user_choice_when_allowed_by_requirem
         .build()
         .await?;
 
-    assert_eq!(
-        config.approvals_reviewer,
-        ApprovalsReviewer::GuardianSubagent
-    );
+    assert_eq!(config.approvals_reviewer, ApprovalsReviewer::AutoReview);
     assert!(
         config
             .startup_warnings

codex-rs/core/src/config_loader/mod.rs

@@ -1048,7 +1048,7 @@ impl From<LegacyManagedConfigToml> for ConfigRequirementsToml {
         }
         if let Some(approvals_reviewer) = approvals_reviewer {
             let mut allowed_reviewers = vec![approvals_reviewer];
-            if approvals_reviewer == ApprovalsReviewer::GuardianSubagent {
+            if approvals_reviewer == ApprovalsReviewer::AutoReview {
                 allowed_reviewers.push(ApprovalsReviewer::User);
             }
             config_requirements_toml.allowed_approvals_reviewers = Some(allowed_reviewers);
@@ -1135,7 +1135,7 @@ foo = "xyzzy"
     fn legacy_managed_config_backfill_allows_user_when_guardian_is_required() {
         let legacy = LegacyManagedConfigToml {
             approval_policy: None,
-            approvals_reviewer: Some(ApprovalsReviewer::GuardianSubagent),
+            approvals_reviewer: Some(ApprovalsReviewer::AutoReview),
             sandbox_mode: None,
         };
 
@@ -1143,10 +1143,7 @@ foo = "xyzzy"
 
         assert_eq!(
             requirements.allowed_approvals_reviewers,
-            Some(vec![
-                ApprovalsReviewer::GuardianSubagent,
-                ApprovalsReviewer::User,
-            ])
+            Some(vec![ApprovalsReviewer::AutoReview, ApprovalsReviewer::User,])
         );
     }
 

codex-rs/core/src/context/permissions_instructions.rs

@@ -188,7 +188,7 @@ fn approval_text(
         ),
     };
 
-    if approvals_reviewer == ApprovalsReviewer::GuardianSubagent
+    if approvals_reviewer == ApprovalsReviewer::AutoReview
         && approval_policy != AskForApproval::Never
     {
         format!("{text}\n\n{AUTO_REVIEW_APPROVAL_SUFFIX}")

codex-rs/core/src/context/permissions_instructions_tests.rs

@@ -197,10 +197,10 @@ fn on_request_includes_tool_guidance_alongside_inline_permission_guidance_when_b
 }
 
 #[test]
-fn guardian_subagent_approvals_append_guardian_specific_guidance() {
+fn auto_review_approvals_append_auto_review_specific_guidance() {
     let text = approval_text(
         AskForApproval::OnRequest,
-        ApprovalsReviewer::GuardianSubagent,
+        ApprovalsReviewer::AutoReview,
         &Policy::empty(),
         /*exec_permission_approvals_enabled*/ false,
         /*request_permissions_tool_enabled*/ false,
@@ -212,10 +212,10 @@ fn guardian_subagent_approvals_append_guardian_specific_guidance() {
 }
 
 #[test]
-fn guardian_subagent_approvals_omit_guardian_specific_guidance_when_approval_is_never() {
+fn auto_review_approvals_omit_auto_review_specific_guidance_when_approval_is_never() {
     let text = approval_text(
         AskForApproval::Never,
-        ApprovalsReviewer::GuardianSubagent,
+        ApprovalsReviewer::AutoReview,
         &Policy::empty(),
         /*exec_permission_approvals_enabled*/ false,
         /*request_permissions_tool_enabled*/ false,

codex-rs/core/src/guardian/review.rs

@@ -146,7 +146,7 @@ pub(crate) fn routes_approval_to_guardian(turn: &TurnContext) -> bool {
     matches!(
         turn.approval_policy.value(),
         AskForApproval::OnRequest | AskForApproval::Granular(_)
-    ) && turn.config.approvals_reviewer == ApprovalsReviewer::GuardianSubagent
+    ) && turn.config.approvals_reviewer == ApprovalsReviewer::AutoReview
 }
 
 pub(crate) fn is_guardian_reviewer_source(

codex-rs/core/src/guardian/tests.rs

@@ -909,7 +909,7 @@ async fn routes_approval_to_guardian_requires_guardian_reviewer() {
 
     assert!(!routes_approval_to_guardian(&turn));
 
-    config.approvals_reviewer = ApprovalsReviewer::GuardianSubagent;
+    config.approvals_reviewer = ApprovalsReviewer::AutoReview;
     turn.config = Arc::new(config);
 
     assert!(routes_approval_to_guardian(&turn));
@@ -919,7 +919,7 @@ async fn routes_approval_to_guardian_requires_guardian_reviewer() {
 async fn routes_approval_to_guardian_allows_granular_review_policy() {
     let (_session, mut turn) = crate::session::tests::make_session_and_context().await;
     let mut config = (*turn.config).clone();
-    config.approvals_reviewer = ApprovalsReviewer::GuardianSubagent;
+    config.approvals_reviewer = ApprovalsReviewer::AutoReview;
     turn.config = Arc::new(config);
     turn.approval_policy
         .set(AskForApproval::Granular(GranularApprovalConfig {

codex-rs/core/src/mcp_tool_call_tests.rs

@@ -1411,7 +1411,7 @@ async fn guardian_mode_skips_auto_when_annotations_do_not_require_approval() {
         .expect("test setup should allow updating approval policy");
     let mut config = (*turn_context.config).clone();
     config.model_provider.base_url = Some(format!("{}/v1", server.uri()));
-    config.approvals_reviewer = ApprovalsReviewer::GuardianSubagent;
+    config.approvals_reviewer = ApprovalsReviewer::AutoReview;
     let config = Arc::new(config);
     let models_manager = Arc::new(crate::test_support::models_manager_with_provider(
         config.codex_home.to_path_buf(),
@@ -1490,7 +1490,7 @@ async fn guardian_mode_mcp_denial_returns_rationale_message() {
         .expect("test setup should allow updating approval policy");
     let mut config = (*turn_context.config).clone();
     config.model_provider.base_url = Some(format!("{}/v1", server.uri()));
-    config.approvals_reviewer = ApprovalsReviewer::GuardianSubagent;
+    config.approvals_reviewer = ApprovalsReviewer::AutoReview;
     let config = Arc::new(config);
     let models_manager = Arc::new(crate::test_support::models_manager_with_provider(
         config.codex_home.to_path_buf(),
@@ -1947,7 +1947,7 @@ async fn approve_mode_routes_arc_ask_user_to_guardian_when_guardian_reviewer_is_
     let mut config = (*turn_context.config).clone();
     config.chatgpt_base_url = server.uri();
     config.model_provider.base_url = Some(format!("{}/v1", server.uri()));
-    config.approvals_reviewer = ApprovalsReviewer::GuardianSubagent;
+    config.approvals_reviewer = ApprovalsReviewer::AutoReview;
     let config = Arc::new(config);
     let models_manager = Arc::new(crate::test_support::models_manager_with_provider(
         config.codex_home.to_path_buf(),

codex-rs/core/src/session/tests.rs

@@ -3827,7 +3827,7 @@ async fn user_turn_updates_approvals_reviewer() {
             }],
             cwd: config.cwd.to_path_buf(),
             approval_policy: config.permissions.approval_policy.value(),
-            approvals_reviewer: Some(codex_config::types::ApprovalsReviewer::GuardianSubagent),
+            approvals_reviewer: Some(codex_config::types::ApprovalsReviewer::AutoReview),
             sandbox_policy: config.permissions.sandbox_policy.get().clone(),
             model: turn_context.model_info.slug.clone(),
             effort: config.model_reasoning_effort,
@@ -3843,7 +3843,7 @@ async fn user_turn_updates_approvals_reviewer() {
     let state = session.state.lock().await;
     assert_eq!(
         state.session_configuration.approvals_reviewer,
-        codex_config::types::ApprovalsReviewer::GuardianSubagent
+        codex_config::types::ApprovalsReviewer::AutoReview
     );
 }
 

codex-rs/core/src/session/tests/guardian_tests.rs

@@ -88,7 +88,7 @@ async fn request_permissions_routes_to_guardian_when_reviewer_is_enabled() {
         .enable(Feature::GuardianApproval)
         .expect("test setup should allow enabling guardian approvals");
     let mut config = (*turn_context_raw.config).clone();
-    config.approvals_reviewer = ApprovalsReviewer::GuardianSubagent;
+    config.approvals_reviewer = ApprovalsReviewer::AutoReview;
     config.model_provider.base_url = Some(format!("{}/v1", server.uri()));
     let config = Arc::new(config);
     let models_manager = Arc::new(crate::test_support::models_manager_with_provider(
@@ -166,7 +166,7 @@ async fn request_permissions_guardian_review_stops_when_cancelled() {
         .enable(Feature::GuardianApproval)
         .expect("test setup should allow enabling guardian approvals");
     let mut config = (*turn_context_raw.config).clone();
-    config.approvals_reviewer = ApprovalsReviewer::GuardianSubagent;
+    config.approvals_reviewer = ApprovalsReviewer::AutoReview;
     config.model_provider.base_url = Some(format!("{}/v1", server.uri()));
     let config = Arc::new(config);
     let models_manager = Arc::new(crate::test_support::models_manager_with_provider(