feat: Add delete policy in recon page and system operation log.

src/log/SystemOperationLog.h

@@ -13,6 +13,7 @@ public:
     SystemOperationLog();
     ~SystemOperationLog(); 
     void reloadFile();
+    static void cleanHistoryLog();
 
 public slots:
     void log(const QString& aOperationText, const QDateTime& aOperationDate);