Mark enhanced execpolicy suggestions as experimental

In codex-rs/core/src/features.rs, move enhanced_exec_policy_suggestions from UnderDevelopment to Experimental with menu metadata so it appears in experimental feature surfaces.

In codex-rs/core/src/features_tests.rs, add explicit coverage for the new experimental stage, display name, description, and default-off behavior.

codex-rs/core/src/features.rs

@@ -682,7 +682,11 @@ pub const FEATURES: &[FeatureSpec] = &[
     FeatureSpec {
         id: Feature::EnhancedExecPolicySuggestions,
         key: "enhanced_exec_policy_suggestions",
-        stage: Stage::UnderDevelopment,
+        stage: Stage::Experimental {
+            name: "Enhanced exec policy suggestions",
+            menu_description: "When Codex proposes a reusable exec policy prefix, stop before the first flag-like argument and use the first segment of a compound shell command.",
+            announcement: "",
+        },
         default_enabled: false,
     },
     FeatureSpec {

codex-rs/core/src/features_tests.rs

@@ -85,6 +85,29 @@ fn guardian_approval_is_experimental_and_user_toggleable() {
     assert_eq!(Feature::GuardianApproval.default_enabled(), false);
 }
 
+#[test]
+fn enhanced_exec_policy_suggestions_is_experimental_and_user_toggleable() {
+    let spec = Feature::EnhancedExecPolicySuggestions.info();
+    let stage = spec.stage;
+
+    assert!(matches!(stage, Stage::Experimental { .. }));
+    assert_eq!(
+        stage.experimental_menu_name(),
+        Some("Enhanced exec policy suggestions")
+    );
+    assert_eq!(
+        stage.experimental_menu_description(),
+        Some(
+            "When Codex proposes a reusable exec policy prefix, stop before the first flag-like argument and use the first segment of a compound shell command."
+        )
+    );
+    assert_eq!(stage.experimental_announcement(), None);
+    assert_eq!(
+        Feature::EnhancedExecPolicySuggestions.default_enabled(),
+        false
+    );
+}
+
 #[test]
 fn request_permissions_is_under_development() {
     assert_eq!(