fix: 修复权限级联同步缺口

修复 Manticore 搜索索引在特定场景下 allowed_users 权限未能正确同步的问题：

  Observer.updated 补充：
  - ProjectUserObserver: 处理项目成员移交时的权限级联
  - ProjectTaskUserObserver: 处理任务成员移交时的权限更新

  批量操作绕过 Observer 修复（delete → remove）：
  - FileUser: deleteFileAll/deleteFileUser 方法
  - ProjectTask: 可见性设置时的批量删除
  - ProjectController: 子任务升级和任务复制时的批量删除

  文件批量更新封装：
  - File 新增 updateChildFilesUserid() 方法，统一处理子文件 userid
    更新及 Manticore 同步

app/Models/ProjectTask.php

@@ -800,7 +800,7 @@ class ProjectTask extends AbstractModel
                     $this->visibility = $data["visibility"];
                     ProjectTask::whereParentId($data['task_id'])->change(['visibility' => $data["visibility"]]);
                 }
-                ProjectTaskVisibilityUser::whereTaskId($data['task_id'])->delete();
+                ProjectTaskVisibilityUser::whereTaskId($data['task_id'])->remove();
                 if (Arr::exists($data, 'visibility_appointor')) {
                     foreach ($data['visibility_appointor'] as $uid) {
                         if ($uid) {