fix: 菜单固定为全局

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

@@ -1,8 +1,11 @@
 using MediatR;
 using TakeoutSaaS.Application.Identity.Commands;
 using TakeoutSaaS.Application.Identity.Contracts;
+using TakeoutSaaS.Application.Identity;
 using TakeoutSaaS.Domain.Identity.Entities;
 using TakeoutSaaS.Domain.Identity.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Constants;
+using TakeoutSaaS.Shared.Abstractions.Exceptions;
 using TakeoutSaaS.Shared.Abstractions.Tenancy;
 
 namespace TakeoutSaaS.Application.Identity.Handlers;
@@ -18,7 +21,13 @@ public sealed class CreateMenuCommandHandler(
     /// <inheritdoc />
     public async Task<MenuDefinitionDto> Handle(CreateMenuCommand request, CancellationToken cancellationToken)
     {
-        // 1. 构造实体
+        // 1. 菜单固定时禁止新增
+        if (!MenuPolicy.CanMaintainMenus)
+        {
+            throw new BusinessException(ErrorCodes.Forbidden, "菜单已固定，禁止新增");
+        }
+
+        // 2. 构造实体
         var tenantId = tenantProvider.GetCurrentTenantId();
         var entity = new MenuDefinition
         {
@@ -41,11 +50,11 @@ public sealed class CreateMenuCommandHandler(
                 : System.Text.Json.JsonSerializer.Serialize(request.AuthList)
         };
 
-        // 2. 持久化
+        // 3. 持久化
         await menuRepository.AddAsync(entity, cancellationToken);
         await menuRepository.SaveChangesAsync(cancellationToken);
 
-        // 3. 返回 DTO
+        // 4. 返回 DTO
         return MenuMapper.ToDto(entity);
     }
 }

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

@@ -1,6 +1,9 @@
 using MediatR;
+using TakeoutSaaS.Application.Identity;
 using TakeoutSaaS.Application.Identity.Commands;
 using TakeoutSaaS.Domain.Identity.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Constants;
+using TakeoutSaaS.Shared.Abstractions.Exceptions;
 using TakeoutSaaS.Shared.Abstractions.Tenancy;
 
 namespace TakeoutSaaS.Application.Identity.Handlers;
@@ -16,14 +19,20 @@ public sealed class DeleteMenuCommandHandler(
     /// <inheritdoc />
     public async Task<bool> Handle(DeleteMenuCommand request, CancellationToken cancellationToken)
     {
-        // 1. 删除目标及可能的孤儿由外层保证
+        // 1. 菜单固定时禁止删除
+        if (!MenuPolicy.CanMaintainMenus)
+        {
+            throw new BusinessException(ErrorCodes.Forbidden, "菜单已固定，禁止删除");
+        }
+
+        // 2. 删除目标及可能的孤儿由外层保证
         var tenantId = tenantProvider.GetCurrentTenantId();
         await menuRepository.DeleteAsync(request.Id, tenantId, cancellationToken);
 
-        // 2. 持久化
+        // 3. 持久化
         await menuRepository.SaveChangesAsync(cancellationToken);
 
-        // 3. 返回执行结果
+        // 4. 返回执行结果
         return true;
     }
 }

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

@@ -1,4 +1,5 @@
 using MediatR;
+using TakeoutSaaS.Application.Identity;
 using TakeoutSaaS.Application.Identity.Commands;
 using TakeoutSaaS.Application.Identity.Contracts;
 using TakeoutSaaS.Domain.Identity.Repositories;
@@ -19,12 +20,18 @@ public sealed class UpdateMenuCommandHandler(
     /// <inheritdoc />
     public async Task<MenuDefinitionDto?> Handle(UpdateMenuCommand request, CancellationToken cancellationToken)
     {
-        // 1. 校验存在
+        // 1. 菜单固定时禁止修改
+        if (!MenuPolicy.CanMaintainMenus)
+        {
+            throw new BusinessException(ErrorCodes.Forbidden, "菜单已固定，禁止修改");
+        }
+
+        // 2. 校验存在
         var tenantId = tenantProvider.GetCurrentTenantId();
         var entity = await menuRepository.FindByIdAsync(request.Id, tenantId, cancellationToken)
             ?? throw new BusinessException(ErrorCodes.NotFound, "菜单不存在");
 
-        // 2. 更新字段
+        // 3. 更新字段
         entity.ParentId = request.ParentId;
         entity.Name = request.Name.Trim();
         entity.Path = request.Path.Trim();
@@ -42,11 +49,11 @@ public sealed class UpdateMenuCommandHandler(
             ? null
             : System.Text.Json.JsonSerializer.Serialize(request.AuthList);
 
-        // 3. 持久化
+        // 4. 持久化
         await menuRepository.UpdateAsync(entity, cancellationToken);
         await menuRepository.SaveChangesAsync(cancellationToken);
 
-        // 4. 返回 DTO
+        // 5. 返回 DTO
         return MenuMapper.ToDto(entity);
     }
 }

src/Application/TakeoutSaaS.Application/Identity/MenuPolicy.cs

@@ -0,0 +1,12 @@
+namespace TakeoutSaaS.Application.Identity;
+
+/// <summary>
+/// 菜单维护策略（固定菜单时禁用增删改）。
+/// </summary>
+public static class MenuPolicy
+{
+    /// <summary>
+    /// 是否允许维护菜单（创建/更新/删除）。
+    /// </summary>
+    public const bool CanMaintainMenus = false;
+}