Add context to sampling retry logs (#33963)

## What changed

- Add structured `turn_id`, `retries`, `max_retries`, and `sampling_error` fields to sampling-stream retry warnings.
- Add a focused test that captures the warning and verifies its retry and error context.

GitOrigin-RevId: dea868875d162b3f97b3c8a256359278f7267c1c

codex-rs/core/src/responses_retry.rs

@@ -89,6 +89,10 @@ fn log_retry(
     match request {
         ResponsesStreamRequest::Sampling => {
             warn!(
+                turn_id = %turn_context.sub_id,
+                retries,
+                max_retries,
+                sampling_error = %err,
                 "stream disconnected - retrying sampling request ({retries}/{max_retries} in {delay:?})...",
             );
         }
@@ -103,3 +107,7 @@ fn log_retry(
         }
     }
 }
+
+#[cfg(test)]
+#[path = "responses_retry_tests.rs"]
+mod tests;

codex-rs/core/src/responses_retry_tests.rs

@@ -0,0 +1,46 @@
+use super::ResponsesStreamRequest;
+use super::log_retry;
+use crate::session::tests::make_session_and_context;
+use codex_protocol::error::CodexErr;
+use std::time::Duration;
+use tracing_test::internal::MockWriter;
+
+#[tokio::test]
+async fn sampling_retry_logs_stream_error_context() {
+    let (_session, turn_context) = make_session_and_context().await;
+    let buffer: &'static std::sync::Mutex<Vec<u8>> =
+        Box::leak(Box::new(std::sync::Mutex::new(Vec::new())));
+    let subscriber = tracing_subscriber::fmt()
+        .with_ansi(false)
+        .with_max_level(tracing::Level::WARN)
+        .with_writer(MockWriter::new(buffer))
+        .finish();
+    let _subscriber_guard = tracing::subscriber::set_default(subscriber);
+
+    log_retry(
+        ResponsesStreamRequest::Sampling,
+        &turn_context,
+        &CodexErr::Stream(
+            "websocket closed by server before response.completed".to_string(),
+            None,
+        ),
+        /*retries*/ 2,
+        /*max_retries*/ 5,
+        Duration::from_secs(1),
+    );
+
+    let logs = String::from_utf8(
+        buffer
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner)
+            .clone(),
+    )
+    .expect("retry log should be valid utf-8");
+    assert!(logs.contains("stream disconnected - retrying sampling request"));
+    assert!(logs.contains(&format!("turn_id={}", turn_context.sub_id)));
+    assert!(logs.contains("retries=2"));
+    assert!(logs.contains("max_retries=5"));
+    assert!(logs.contains(
+        "sampling_error=stream disconnected before completion: websocket closed by server before response.completed"
+    ));
+}