fix(host): 防止主节点重复并修复 setMaster 权限

Clear all is_master flags before electing new master to prevent multiple master records. Fix setMaster annotation from @auth true to proper @NodeAnotation format so permission node is generated correctly.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

app/admin/controller/system/Host.php

@@ -10,4 +10,13 @@ use base\admin\controller\system\HostBase;
  */
 class Host extends HostBase
 {
+    /**
+     * 设置主节点.
+     *
+     * @\app\admin\service\annotation\NodeAnotation(title="设置主节点")
+     */
+    public function setMaster()
+    {
+        return parent::setMaster();
+    }
 }