feat: persist sgclaw browser conversations

tests/runtime_task_flow_test.rs

@@ -68,6 +68,10 @@ fn submit_task_sends_three_commands_and_finishes_with_task_complete() {
         &tool,
         BrowserMessage::SubmitTask {
             instruction: "打开百度搜索天气".to_string(),
+            conversation_id: String::new(),
+            messages: vec![],
+            page_url: String::new(),
+            page_title: String::new(),
         },
     )
     .unwrap();