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>

extend/base/common/service/HostServiceBase.php

@@ -79,6 +79,8 @@ class HostServiceBase
             // 主节点自动选举：若无在线主节点，当前节点自动成为主节点
             $master = SystemHost::where('is_master', 1)->where('status', 1)->find();
             if (empty($master)) {
+                // 先清除所有旧的主节点标记（含已离线的），避免出现多个 is_master=1
+                SystemHost::where('is_master', 1)->update(['is_master' => 0]);
                 $host->is_master = 1;
                 $host->save();
                 Log::info("节点 [{$nodeId}] 自动当选为主节点。");