show "Viewed Image" when the model views an image (#4475)

<img width="1022" height="339" alt="Screenshot 2025-09-29 at 4 22 00 PM"
src="https://github.com/user-attachments/assets/12da7358-19be-4010-a71b-496ede6dfbbf"
/>

codex-rs/core/src/rollout/policy.rs

@@ -70,6 +70,7 @@ pub(crate) fn should_persist_event_msg(ev: &EventMsg) -> bool {
         | EventMsg::ListCustomPromptsResponse(_)
         | EventMsg::PlanUpdate(_)
         | EventMsg::ShutdownComplete
+        | EventMsg::ViewImageToolCall(_)
         | EventMsg::ConversationPath(_) => false,
     }
 }