fix(multiplayer): repair allocated compose verification

server/supervisor/supervisor.go

@@ -226,6 +226,12 @@ func (s *Supervisor) Start(ctx context.Context) error {
 		s.cmd = exec.CommandContext(ctx, s.config.Command[0], s.config.Command[1:]...)
 	}
 	s.cmd.Env = env
+	// A server's structured stdout/stderr is its operational interface. The
+	// zero value for exec.Cmd streams is /dev/null, which would make a child
+	// startup failure invisible to Docker, Kubernetes, and the Compose
+	// readiness harness while the supervisor can report only "exit status 1".
+	s.cmd.Stdout = os.Stdout
+	s.cmd.Stderr = os.Stderr
 	if err := s.cmd.Start(); err != nil {
 		return err
 	}