chore: add default value for backoff

cmd/bitsrun/main.go

@@ -18,7 +18,7 @@ func main() {
 			if err = controllers.Login(nil, false); err != nil {
 				logger.Errorln("登录出错: ", err)
 				if !config.Settings.Log.DebugLevel {
-					logger.Infoln("开启调试日志（debug_level）获取详细信息")
+					logger.Infoln("开启调试日志 (debug_level) 获取详细信息")
 				}
 				return
 			}

internal/config/default.go

@@ -41,5 +41,10 @@ var defaultConfig = ConfFromFile{
 		CustomHeader: map[string]interface{}{
 			"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36",
 		},
+		Backoff: BackoffConf{
+			InitialDuration: 2,
+			MaxDuration:     300,
+			ExponentFactor:  1,
+		},
 	},
 }