session tweak, update docs

media/server/src/session.rs

@@ -112,6 +112,7 @@ impl Session {
         // Scene relay: Unix socket for Python scene detection.
         let socket_path = stream_dir.join(SCENE_SOCKET_NAME);
         let (scene_tx, scene_rx) = tokio::sync::mpsc::channel(32);
+        info!("Scene relay: spawning for {}", socket_path.display());
         tokio::spawn(scene_relay_task(socket_path, scene_rx));
 
         // Tell Python which session dir to watch.
@@ -217,9 +218,22 @@ async fn scene_relay_task(
                         last_keyframe = Some(pkt.data.clone());
                     }
                     let stream = client.as_mut().unwrap();
-                    if stream.write_all(&pkt.data).await.is_err() {
-                        info!("Scene relay: client disconnected");
-                        client = None;
+                    // Use a short timeout so a slow reader doesn't stall us.
+                    // A stalled relay would queue old frames — better to drop.
+                    let write_result = tokio::time::timeout(
+                        std::time::Duration::from_millis(100),
+                        stream.write_all(&pkt.data),
+                    ).await;
+                    match write_result {
+                        Ok(Ok(())) => {}
+                        Ok(Err(_)) => {
+                            info!("Scene relay: client disconnected");
+                            client = None;
+                        }
+                        Err(_) => {
+                            // Timeout — reader too slow, drop this packet.
+                            debug!("Scene relay: slow reader, dropping packet");
+                        }
                     }
                 }
                 None => break, // Channel closed, session ending.