fix: 主机监控重复主机名 - 移除select旁冗余hostname显示

frontend/src/pages/HostMonitor.tsx

@@ -294,8 +294,7 @@ export function HostMonitor() {
           </Select>
           {serverInfo && (
             <span className="text-xs text-[var(--dg-text-muted)] ml-2">
-              <span className="text-sm font-semibold text-[var(--dg-text-primary)] mr-2">{selectedHost}</span>
-              {serverInfo.os || ''} | {serverInfo.cpu_cores || '?'} 核 | {serverInfo.mem_total ? `${serverInfo.mem_total.toFixed(0)}GB` : '?'}
+              {serverInfo.os || ''}{serverInfo.cpu_cores ? ` | ${serverInfo.cpu_cores} 核` : ''}{serverInfo.mem_total ? ` | ${serverInfo.mem_total.toFixed(0)}GB` : ''}
             </span>
           )}
         </div>