fix(tunnel): prevent tunnel backpressure buffering from exhausting memory and cancel stream handlers before TLS shutdown

rust/crates/remoteingress-core/src/hub.rs

@@ -844,17 +844,19 @@ async fn handle_edge_connection(
         }
     }
 
-    // Graceful TLS shutdown: send close_notify so the edge sees a clean disconnect
-    // instead of "peer closed connection without sending TLS close_notify".
+    // Cancel stream tokens FIRST so stream handlers exit immediately.
+    // If we TLS-shutdown first, stream handlers are stuck sending to dead channels
+    // for up to 2 seconds while the shutdown times out on a dead connection.
+    edge_token.cancel();
+    config_handle.abort();
+
+    // Graceful TLS shutdown: send close_notify so the edge sees a clean disconnect.
+    // Stream handlers are already cancelled, so no new data is being produced.
     let mut tls_stream = tunnel_io.into_inner();
     let _ = tokio::time::timeout(
         Duration::from_secs(2),
         tls_stream.shutdown(),
     ).await;
-
-    // Cleanup: cancel edge token to propagate to all child tasks
-    edge_token.cancel();
-    config_handle.abort();
     {
         let mut edges = connected.lock().await;
         edges.remove(&edge_id);