Add safety check notification and error handling (#19055)

Adds a new app-server notification that fires when a user account has
been flagged for potential safety reasons.

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

@@ -331,6 +331,8 @@ use codex_protocol::protocol::InitialHistory;
 use codex_protocol::protocol::McpServerRefreshConfig;
 use codex_protocol::protocol::ModelRerouteEvent;
 use codex_protocol::protocol::ModelRerouteReason;
+use codex_protocol::protocol::ModelVerification;
+use codex_protocol::protocol::ModelVerificationEvent;
 use codex_protocol::protocol::NetworkApprovalContext;
 use codex_protocol::protocol::NonSteerableTurnKind;
 use codex_protocol::protocol::Op;
@@ -2385,6 +2387,18 @@ impl Session {
         true
     }
 
+    pub(crate) async fn emit_model_verification(
+        self: &Arc<Self>,
+        turn_context: &Arc<TurnContext>,
+        verifications: Vec<ModelVerification>,
+    ) {
+        self.send_event(
+            turn_context,
+            EventMsg::ModelVerification(ModelVerificationEvent { verifications }),
+        )
+        .await;
+    }
+
     pub(crate) async fn replace_history(
         &self,
         items: Vec<ResponseItem>,