fix main (#30276)

Introduced by a merge race around thread.history_mode.

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

@@ -9197,6 +9197,7 @@ async fn attach_in_memory_thread_store(
             dynamic_tools: Vec::new(),
             selected_capability_roots: Vec::new(),
             multi_agent_version: None,
+            history_mode: Default::default(),
             initial_window_id: Uuid::now_v7().to_string(),
             metadata: ThreadPersistenceMetadata {
                 cwd: Some(config.cwd.to_path_buf()),