refactor(mikrotikBackupRoutes, mikrotikBackupScheduler): update backup export command to use /rest/execute with compact terse script for improved reliability

backend/routes/mikrotikBackupRoutes.js

@@ -261,8 +261,8 @@ async function runBackupNow(req, res) {
       throw e;
     }
 
-    // /rest/export с compact, как в планировщике
-    const resp = await client.command('export', { compact: '' });
+    // /rest/execute с командой "/export compact terse", как в планировщике
+    const resp = await client.command('execute', { script: '/export compact terse' });
     const data = resp && resp.data;
     let config = '';
     if (typeof data === 'string') config = data;