feat: add permission hierarchy tree

src/Api/TakeoutSaaS.AdminApi/Controllers/PermissionsController.cs

@@ -37,6 +37,27 @@ public sealed class PermissionsController(IMediator mediator) : BaseApiControlle
         return ApiResponse<PagedResult<PermissionDto>>.Ok(result);
     }
 
+    /// <summary>
+    /// 获取权限树。
+    /// </summary>
+    /// <param name="keyword">关键字（可选）。</param>
+    /// <param name="cancellationToken">取消标记。</param>
+    /// <returns>权限树列表。</returns>
+    [HttpGet("tree")]
+    [PermissionAuthorize("identity:permission:read")]
+    [ProducesResponseType(typeof(ApiResponse<IReadOnlyList<PermissionTreeDto>>), StatusCodes.Status200OK)]
+    public async Task<ApiResponse<IReadOnlyList<PermissionTreeDto>>> Tree([FromQuery] string? keyword, CancellationToken cancellationToken)
+    {
+        // 1. 构造查询对象
+        var query = new PermissionTreeQuery { Keyword = keyword };
+
+        // 2. 查询权限树
+        var result = await mediator.Send(query, cancellationToken);
+
+        // 3. 返回结果
+        return ApiResponse<IReadOnlyList<PermissionTreeDto>>.Ok(result);
+    }
+
     /// <summary>
     /// 创建权限。
     /// </summary>