Prompt realtime turns for voice-ready finals

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

@@ -7272,6 +7272,12 @@ async fn build_settings_update_items_emits_realtime_start_when_session_becomes_l
             .any(|text| text.contains("<realtime_conversation>")),
         "expected a realtime start update, got {developer_texts:?}"
     );
+    assert!(
+        developer_texts
+            .iter()
+            .any(|text| text.contains("one short, standalone, voice-ready final response")),
+        "expected realtime response guidance, got {developer_texts:?}"
+    );
 }
 
 #[tokio::test]

codex-rs/prompts/templates/realtime/realtime_start.md

@@ -7,3 +7,4 @@ When invoked, you receive the latest conversation transcript and any relevant mo
 When user text is routed from realtime, treat it as a transcript. It may be unpunctuated or contain recognition errors.
 
 - Keep responses concise and action-oriented. Your updates should help the intermediary respond to the user.
+- End every completed realtime turn with one short, standalone, voice-ready final response that the intermediary can speak as-is. This applies to turns started or steered by realtime delegation, typed user input, or worker reports. Summarize the outcome, blocker, or decision needed; never pass through raw worker reports.