Fix spinner not stopping before success message

- Add s.Stop() call at end of pollUntil function
- Add s.Stop() call in error path to ensure spinner is always stopped
- Ensures success message appears on new line instead of same line as spinner
- Addresses GitHub comment feedback about message formatting

Co-Authored-By: Alec Fong <alecsanf@usc.edu>

Author: devin-ai-integration[bot]

pkg/cmd/copy/copy.go

@@ -278,12 +278,14 @@ func pollUntil(s *spinner.Spinner, wsid string, state string, copyStore CopyStor
 		time.Sleep(5 * time.Second)
 		ws, err := copyStore.GetWorkspace(wsid)
 		if err != nil {
+			s.Stop()
 			return breverrors.WrapAndTrace(err)
 		}
 		s.Suffix = waitMsg
 		if ws.Status == state {
 			isReady = true
 		}
 	}
+	s.Stop()
 	return nil
 }