feat: 管理端核心实体CRUD补齐

src/Application/TakeoutSaaS.Application/App/Merchants/Commands/DeleteMerchantCommand.cs

@@ -0,0 +1,14 @@
+using MediatR;
+
+namespace TakeoutSaaS.Application.App.Merchants.Commands;
+
+/// <summary>
+/// 删除商户命令。
+/// </summary>
+public sealed class DeleteMerchantCommand : IRequest<bool>
+{
+    /// <summary>
+    /// 商户 ID。
+    /// </summary>
+    public long MerchantId { get; init; }
+}

src/Application/TakeoutSaaS.Application/App/Merchants/Commands/UpdateMerchantCommand.cs

@@ -0,0 +1,51 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Merchants.Dto;
+using TakeoutSaaS.Domain.Merchants.Enums;
+
+namespace TakeoutSaaS.Application.App.Merchants.Commands;
+
+/// <summary>
+/// 更新商户命令。
+/// </summary>
+public sealed class UpdateMerchantCommand : IRequest<MerchantDto?>
+{
+    /// <summary>
+    /// 商户 ID。
+    /// </summary>
+    public long MerchantId { get; set; }
+
+    /// <summary>
+    /// 品牌名称。
+    /// </summary>
+    public string BrandName { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 品牌简称。
+    /// </summary>
+    public string? BrandAlias { get; set; }
+
+    /// <summary>
+    /// Logo 地址。
+    /// </summary>
+    public string? LogoUrl { get; set; }
+
+    /// <summary>
+    /// 品类。
+    /// </summary>
+    public string? Category { get; set; }
+
+    /// <summary>
+    /// 联系电话。
+    /// </summary>
+    public string ContactPhone { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 联系邮箱。
+    /// </summary>
+    public string? ContactEmail { get; set; }
+
+    /// <summary>
+    /// 入驻状态。
+    /// </summary>
+    public MerchantStatus Status { get; set; }
+}

src/Application/TakeoutSaaS.Application/App/Merchants/Handlers/DeleteMerchantCommandHandler.cs

@@ -0,0 +1,40 @@
+using MediatR;
+using Microsoft.Extensions.Logging;
+using TakeoutSaaS.Application.App.Merchants.Commands;
+using TakeoutSaaS.Domain.Merchants.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Application.App.Merchants.Handlers;
+
+/// <summary>
+/// 删除商户命令处理器。
+/// </summary>
+public sealed class DeleteMerchantCommandHandler(
+    IMerchantRepository merchantRepository,
+    ITenantProvider tenantProvider,
+    ILogger<DeleteMerchantCommandHandler> logger)
+    : IRequestHandler<DeleteMerchantCommand, bool>
+{
+    private readonly IMerchantRepository _merchantRepository = merchantRepository;
+    private readonly ITenantProvider _tenantProvider = tenantProvider;
+    private readonly ILogger<DeleteMerchantCommandHandler> _logger = logger;
+
+    /// <inheritdoc />
+    public async Task<bool> Handle(DeleteMerchantCommand request, CancellationToken cancellationToken)
+    {
+        // 1. 校验存在性
+        var tenantId = _tenantProvider.GetCurrentTenantId();
+        var existing = await _merchantRepository.FindByIdAsync(request.MerchantId, tenantId, cancellationToken);
+        if (existing == null)
+        {
+            return false;
+        }
+
+        // 2. 删除
+        await _merchantRepository.DeleteMerchantAsync(request.MerchantId, tenantId, cancellationToken);
+        await _merchantRepository.SaveChangesAsync(cancellationToken);
+        _logger.LogInformation("删除商户 {MerchantId}", request.MerchantId);
+
+        return true;
+    }
+}

src/Application/TakeoutSaaS.Application/App/Merchants/Handlers/UpdateMerchantCommandHandler.cs

@@ -0,0 +1,65 @@
+using MediatR;
+using Microsoft.Extensions.Logging;
+using TakeoutSaaS.Application.App.Merchants.Commands;
+using TakeoutSaaS.Application.App.Merchants.Dto;
+using TakeoutSaaS.Domain.Merchants.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Application.App.Merchants.Handlers;
+
+/// <summary>
+/// 更新商户命令处理器。
+/// </summary>
+public sealed class UpdateMerchantCommandHandler(
+    IMerchantRepository merchantRepository,
+    ITenantProvider tenantProvider,
+    ILogger<UpdateMerchantCommandHandler> logger)
+    : IRequestHandler<UpdateMerchantCommand, MerchantDto?>
+{
+    private readonly IMerchantRepository _merchantRepository = merchantRepository;
+    private readonly ITenantProvider _tenantProvider = tenantProvider;
+    private readonly ILogger<UpdateMerchantCommandHandler> _logger = logger;
+
+    /// <inheritdoc />
+    public async Task<MerchantDto?> Handle(UpdateMerchantCommand request, CancellationToken cancellationToken)
+    {
+        // 1. 读取现有商户
+        var tenantId = _tenantProvider.GetCurrentTenantId();
+        var existing = await _merchantRepository.FindByIdAsync(request.MerchantId, tenantId, cancellationToken);
+        if (existing == null)
+        {
+            return null;
+        }
+
+        // 2. 更新字段
+        existing.BrandName = request.BrandName.Trim();
+        existing.BrandAlias = request.BrandAlias?.Trim();
+        existing.LogoUrl = request.LogoUrl?.Trim();
+        existing.Category = request.Category?.Trim();
+        existing.ContactPhone = request.ContactPhone.Trim();
+        existing.ContactEmail = request.ContactEmail?.Trim();
+        existing.Status = request.Status;
+
+        // 3. 持久化
+        await _merchantRepository.UpdateMerchantAsync(existing, cancellationToken);
+        await _merchantRepository.SaveChangesAsync(cancellationToken);
+        _logger.LogInformation("更新商户 {MerchantId} - {BrandName}", existing.Id, existing.BrandName);
+
+        // 4. 返回 DTO
+        return MapToDto(existing);
+    }
+
+    private static MerchantDto MapToDto(Domain.Merchants.Entities.Merchant merchant) => new()
+    {
+        Id = merchant.Id,
+        TenantId = merchant.TenantId,
+        BrandName = merchant.BrandName,
+        BrandAlias = merchant.BrandAlias,
+        LogoUrl = merchant.LogoUrl,
+        Category = merchant.Category,
+        ContactPhone = merchant.ContactPhone,
+        ContactEmail = merchant.ContactEmail,
+        Status = merchant.Status,
+        JoinedAt = merchant.JoinedAt
+    };
+}