feat: align task pipe protocol and hmac

src/pipe/browser_tool.rs

@@ -97,6 +97,11 @@ impl<T: Transport> BrowserPipeTool<T> {
                         "received duplicate init after handshake".to_string(),
                     ));
                 }
+                BrowserMessage::SubmitTask { .. } => {
+                    return Err(PipeError::UnexpectedMessage(
+                        "received submit_task while waiting for response".to_string(),
+                    ));
+                }
             }
         }
     }