test(daemon): make socket/pty integration tests robust under parallel load

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/spaceshd/src/surface.rs

@@ -74,7 +74,7 @@ mod tests {
         }
     }
 
-    #[tokio::test]
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn attach_receives_output() {
         let pty = PtyHandle::spawn(spec("printf HELLO; sleep 0.3")).unwrap();
         let (exit_tx, _exit_rx) = mpsc::unbounded_channel();
@@ -97,7 +97,7 @@ mod tests {
         assert!(String::from_utf8_lossy(&collected).contains("HELLO"));
     }
 
-    #[tokio::test]
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn exit_is_reported() {
         let pty = PtyHandle::spawn(spec("exit 7")).unwrap();
         let (exit_tx, mut exit_rx) = mpsc::unbounded_channel();