feat: add admin menu management crud

src/Application/TakeoutSaaS.Application/Identity/Commands/DeleteMenuCommand.cs

@@ -0,0 +1,11 @@
+using MediatR;
+
+namespace TakeoutSaaS.Application.Identity.Commands;
+
+/// <summary>
+/// 删除菜单命令。
+/// </summary>
+public sealed record DeleteMenuCommand : IRequest<bool>
+{
+    public long Id { get; init; }
+}