docs: 完善身份模块文档注释与字段说明

src/Application/TakeoutSaaS.Application/Identity/Handlers/BindRolePermissionsCommandHandler.cs

@@ -13,6 +13,12 @@ public sealed class BindRolePermissionsCommandHandler(
     ITenantProvider tenantProvider)
     : IRequestHandler<BindRolePermissionsCommand, bool>
 {
+    /// <summary>
+    /// 处理角色权限绑定请求。
+    /// </summary>
+    /// <param name="request">绑定命令。</param>
+    /// <param name="cancellationToken">取消标记。</param>
+    /// <returns>执行结果。</returns>
     public async Task<bool> Handle(BindRolePermissionsCommand request, CancellationToken cancellationToken)
     {
         // 1. 获取租户上下文