Add websocket telemetry metrics and labels (#10316)

Summary
- expose websocket telemetry hooks through the responses client so
request durations and event processing can be reported
- record websocket request/event metrics and emit runtime telemetry
events that the history UI now surfaces
- improve tests to cover websocket telemetry reporting and guard runtime
summary updates


<img width="824" height="79" alt="Screenshot 2026-01-31 at 5 28 12 PM"
src="https://github.com/user-attachments/assets/ea9a7965-d8b4-4e3c-a984-ef4fdc44c81d"
/>

codex-rs/core/src/client.rs

@@ -21,6 +21,7 @@ use codex_api::ResponsesWebsocketClient as ApiWebSocketResponsesClient;
 use codex_api::ResponsesWebsocketConnection as ApiWebSocketConnection;
 use codex_api::SseTelemetry;
 use codex_api::TransportError;
+use codex_api::WebsocketTelemetry;
 use codex_api::build_conversation_headers;
 use codex_api::common::Reasoning;
 use codex_api::common::ResponsesWsRequest;
@@ -46,6 +47,8 @@ use reqwest::StatusCode;
 use serde_json::Value;
 use std::time::Duration;
 use tokio::sync::mpsc;
+use tokio_tungstenite::tungstenite::Error;
+use tokio_tungstenite::tungstenite::Message;
 use tracing::warn;
 
 use crate::AuthManager;
@@ -451,9 +454,14 @@ impl ModelClientSession {
         if needs_new {
             let mut headers = options.extra_headers.clone();
             headers.extend(build_conversation_headers(options.conversation_id.clone()));
+            let websocket_telemetry = self.build_websocket_telemetry();
             let new_conn: ApiWebSocketConnection =
                 ApiWebSocketResponsesClient::new(api_provider, api_auth)
-                    .connect(headers, options.turn_state.clone())
+                    .connect(
+                        headers,
+                        options.turn_state.clone(),
+                        Some(websocket_telemetry),
+                    )
                     .await?;
             self.connection = Some(new_conn);
         }
@@ -650,6 +658,13 @@ impl ModelClientSession {
         let sse_telemetry: Arc<dyn SseTelemetry> = telemetry;
         (request_telemetry, sse_telemetry)
     }
+
+    /// Builds telemetry for the Responses API WebSocket transport.
+    fn build_websocket_telemetry(&self) -> Arc<dyn WebsocketTelemetry> {
+        let telemetry = Arc::new(ApiTelemetry::new(self.state.otel_manager.clone()));
+        let websocket_telemetry: Arc<dyn WebsocketTelemetry> = telemetry;
+        websocket_telemetry
+    }
 }
 
 impl ModelClient {
@@ -849,3 +864,19 @@ impl SseTelemetry for ApiTelemetry {
         self.otel_manager.log_sse_event(result, duration);
     }
 }
+
+impl WebsocketTelemetry for ApiTelemetry {
+    fn on_ws_request(&self, duration: Duration, error: Option<&ApiError>) {
+        let error_message = error.map(std::string::ToString::to_string);
+        self.otel_manager
+            .record_websocket_request(duration, error_message.as_deref());
+    }
+
+    fn on_ws_event(
+        &self,
+        result: &std::result::Result<Option<std::result::Result<Message, Error>>, ApiError>,
+        duration: Duration,
+    ) {
+        self.otel_manager.record_websocket_event(result, duration);
+    }
+}