feat: 系统参数独立表与迁移

src/Domain/TakeoutSaaS.Domain/SystemParameters/Entities/SystemParameter.cs

@@ -0,0 +1,34 @@
+using TakeoutSaaS.Shared.Abstractions.Entities;
+
+namespace TakeoutSaaS.Domain.SystemParameters.Entities;
+
+/// <summary>
+/// 系统参数实体：支持按租户维护的键值型配置。
+/// </summary>
+public sealed class SystemParameter : MultiTenantEntityBase
+{
+    /// <summary>
+    /// 参数键，租户内唯一。
+    /// </summary>
+    public string Key { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 参数值，支持文本或 JSON。
+    /// </summary>
+    public string Value { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 描述信息。
+    /// </summary>
+    public string? Description { get; set; }
+
+    /// <summary>
+    /// 排序值，越小越靠前。
+    /// </summary>
+    public int SortOrder { get; set; } = 100;
+
+    /// <summary>
+    /// 是否启用。
+    /// </summary>
+    public bool IsEnabled { get; set; } = true;
+}

src/Infrastructure/TakeoutSaaS.Infrastructure/App/Persistence/AppDataSeeder.cs

@@ -6,6 +6,7 @@ using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using TakeoutSaaS.Domain.Dictionary.Entities;
 using TakeoutSaaS.Domain.Dictionary.Enums;
+using TakeoutSaaS.Domain.SystemParameters.Entities;
 using TakeoutSaaS.Domain.Tenants.Entities;
 using TakeoutSaaS.Domain.Tenants.Enums;
 using TakeoutSaaS.Infrastructure.App.Options;
@@ -219,8 +220,9 @@ public sealed class AppDataSeeder(
         await dbContext.SaveChangesAsync(cancellationToken);
     }
 
+
     /// <summary>
-    /// 确保系统参数以字典形式幂等种子。
+    /// 确保系统参数以独立表形式可重复种子。
     /// </summary>
     private async Task EnsureSystemParametersAsync(DictionaryDbContext dbContext, long? defaultTenantId, CancellationToken cancellationToken)
     {
@@ -245,37 +247,64 @@ public sealed class AppDataSeeder(
         foreach (var group in grouped)
         {
             var tenantId = group.Key;
-            var dictionaryGroup = await dbContext.DictionaryGroups
+            var existingParameters = await dbContext.SystemParameters
                 .IgnoreQueryFilters()
-                .FirstOrDefaultAsync(x => x.TenantId == tenantId && x.Code == "system_parameters", cancellationToken);
+                .Where(x => x.TenantId == tenantId)
+                .ToListAsync(cancellationToken);
 
-            if (dictionaryGroup == null)
+            foreach (var seed in group)
             {
-                dictionaryGroup = new DictionaryGroup
+                var key = seed.Key.Trim();
+                var existing = existingParameters.FirstOrDefault(x => x.Key.Equals(key, StringComparison.OrdinalIgnoreCase));
+
+                if (existing == null)
                 {
-                    Id = 0,
+                    var parameter = new SystemParameter
-                    TenantId = tenantId,
+                    {
-                    Code = "system_parameters",
+                        Id = 0,
-                    Name = "系统参数",
+                        TenantId = tenantId,
-                    Scope = tenantId == 0 ? DictionaryScope.System : DictionaryScope.Business,
+                        Key = key,
-                    Description = "系统参数配置",
+                        Value = seed.Value.Trim(),
-                    IsEnabled = true
+                        Description = seed.Description?.Trim(),
-                };
+                        SortOrder = seed.SortOrder,
+                        IsEnabled = seed.IsEnabled
+                    };
 
-                await dbContext.DictionaryGroups.AddAsync(dictionaryGroup, cancellationToken);
+                    await dbContext.SystemParameters.AddAsync(parameter, cancellationToken);
-                logger.LogInformation("AppSeed 创建系统参数分组 (Tenant: {TenantId})", tenantId);
+                    continue;
+                }
+
+                var updated = false;
+
+                if (!string.Equals(existing.Value, seed.Value, StringComparison.Ordinal))
+                {
+                    existing.Value = seed.Value.Trim();
+                    updated = true;
+                }
+
+                if (!string.Equals(existing.Description, seed.Description, StringComparison.Ordinal))
+                {
+                    existing.Description = seed.Description?.Trim();
+                    updated = true;
+                }
+
+                if (existing.SortOrder != seed.SortOrder)
+                {
+                    existing.SortOrder = seed.SortOrder;
+                    updated = true;
+                }
+
+                if (existing.IsEnabled != seed.IsEnabled)
+                {
+                    existing.IsEnabled = seed.IsEnabled;
+                    updated = true;
+                }
+
+                if (updated)
+                {
+                    dbContext.SystemParameters.Update(existing);
+                }
             }
-
-            var seedItems = group.Select(x => new DictionarySeedItemOptions
-            {
-                Key = x.Key.Trim(),
-                Value = x.Value.Trim(),
-                Description = x.Description?.Trim(),
-                SortOrder = x.SortOrder,
-                IsEnabled = x.IsEnabled
-            });
-
-            await UpsertDictionaryItemsAsync(dbContext, dictionaryGroup, seedItems, tenantId, cancellationToken);
         }
     }
 

src/Infrastructure/TakeoutSaaS.Infrastructure/Dictionary/Persistence/DictionaryDbContext.cs

@@ -1,6 +1,7 @@
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Metadata.Builders;
 using TakeoutSaaS.Domain.Dictionary.Entities;
+using TakeoutSaaS.Domain.SystemParameters.Entities;
 using TakeoutSaaS.Infrastructure.Common.Persistence;
 using TakeoutSaaS.Shared.Abstractions.Ids;
 using TakeoutSaaS.Shared.Abstractions.Security;
@@ -9,7 +10,7 @@ using TakeoutSaaS.Shared.Abstractions.Tenancy;
 namespace TakeoutSaaS.Infrastructure.Dictionary.Persistence;
 
 /// <summary>
-/// 参数字典 DbContext。
+/// 参数字典 DbContext：承载字典与系统参数。
 /// </summary>
 public sealed class DictionaryDbContext(
     DbContextOptions<DictionaryDbContext> options,
@@ -19,15 +20,20 @@ public sealed class DictionaryDbContext(
     : TenantAwareDbContext(options, tenantProvider, currentUserAccessor, idGenerator)
 {
     /// <summary>
-    /// 字典分组集。
+    /// 字典分组集合。
     /// </summary>
     public DbSet<DictionaryGroup> DictionaryGroups => Set<DictionaryGroup>();
 
     /// <summary>
-    /// 字典项集。
+    /// 字典项集合。
     /// </summary>
     public DbSet<DictionaryItem> DictionaryItems => Set<DictionaryItem>();
 
+    /// <summary>
+    /// 系统参数集合。
+    /// </summary>
+    public DbSet<SystemParameter> SystemParameters => Set<SystemParameter>();
+
     /// <summary>
     /// 配置实体模型。
     /// </summary>
@@ -37,6 +43,7 @@ public sealed class DictionaryDbContext(
         base.OnModelCreating(modelBuilder);
         ConfigureGroup(modelBuilder.Entity<DictionaryGroup>());
         ConfigureItem(modelBuilder.Entity<DictionaryItem>());
+        ConfigureSystemParameter(modelBuilder.Entity<SystemParameter>());
         ApplyTenantQueryFilters(modelBuilder);
     }
 
@@ -87,4 +94,25 @@ public sealed class DictionaryDbContext(
         builder.HasIndex(x => x.TenantId);
         builder.HasIndex(x => new { x.GroupId, x.Key }).IsUnique();
     }
+
+    /// <summary>
+    /// 配置系统参数。
+    /// </summary>
+    /// <param name="builder">实体构建器。</param>
+    private static void ConfigureSystemParameter(EntityTypeBuilder<SystemParameter> builder)
+    {
+        builder.ToTable("system_parameters");
+        builder.HasKey(x => x.Id);
+        builder.Property(x => x.TenantId).IsRequired();
+        builder.Property(x => x.Key).HasMaxLength(128).IsRequired();
+        builder.Property(x => x.Value).HasColumnType("text").IsRequired();
+        builder.Property(x => x.Description).HasMaxLength(512);
+        builder.Property(x => x.SortOrder).HasDefaultValue(100);
+        builder.Property(x => x.IsEnabled).HasDefaultValue(true);
+        ConfigureAuditableEntity(builder);
+        ConfigureSoftDeleteEntity(builder);
+
+        builder.HasIndex(x => x.TenantId);
+        builder.HasIndex(x => new { x.TenantId, x.Key }).IsUnique();
+    }
 }

src/Infrastructure/TakeoutSaaS.Infrastructure/Migrations/DictionaryDb/20251202043204_AddSystemParametersTable.Designer.cs

@@ -0,0 +1,288 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+using TakeoutSaaS.Infrastructure.Dictionary.Persistence;
+
+#nullable disable
+
+namespace TakeoutSaaS.Infrastructure.Migrations.DictionaryDb
+{
+    [DbContext(typeof(DictionaryDbContext))]
+    [Migration("20251202043204_AddSystemParametersTable")]
+    partial class AddSystemParametersTable
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "10.0.0")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("TakeoutSaaS.Domain.Dictionary.Entities.DictionaryGroup", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasComment("实体唯一标识。");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<string>("Code")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)")
+                        .HasComment("分组编码（唯一）。");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasComment("创建时间（UTC）。");
+
+                    b.Property<long?>("CreatedBy")
+                        .HasColumnType("bigint")
+                        .HasComment("创建人用户标识，匿名或系统操作时为 null。");
+
+                    b.Property<DateTime?>("DeletedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasComment("软删除时间（UTC），未删除时为 null。");
+
+                    b.Property<long?>("DeletedBy")
+                        .HasColumnType("bigint")
+                        .HasComment("删除人用户标识（软删除），未删除时为 null。");
+
+                    b.Property<string>("Description")
+                        .HasMaxLength(512)
+                        .HasColumnType("character varying(512)")
+                        .HasComment("描述信息。");
+
+                    b.Property<bool>("IsEnabled")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("boolean")
+                        .HasDefaultValue(true)
+                        .HasComment("是否启用。");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)")
+                        .HasComment("分组名称。");
+
+                    b.Property<int>("Scope")
+                        .HasColumnType("integer")
+                        .HasComment("分组作用域：系统/业务。");
+
+                    b.Property<long>("TenantId")
+                        .HasColumnType("bigint")
+                        .HasComment("所属租户 ID。");
+
+                    b.Property<DateTime?>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasComment("最近一次更新时间（UTC），从未更新时为 null。");
+
+                    b.Property<long?>("UpdatedBy")
+                        .HasColumnType("bigint")
+                        .HasComment("最后更新人用户标识，匿名或系统操作时为 null。");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("TenantId");
+
+                    b.HasIndex("TenantId", "Code")
+                        .IsUnique();
+
+                    b.ToTable("dictionary_groups", null, t =>
+                        {
+                            t.HasComment("参数字典分组（系统参数、业务参数）。");
+                        });
+                });
+
+            modelBuilder.Entity("TakeoutSaaS.Domain.Dictionary.Entities.DictionaryItem", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasComment("实体唯一标识。");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasComment("创建时间（UTC）。");
+
+                    b.Property<long?>("CreatedBy")
+                        .HasColumnType("bigint")
+                        .HasComment("创建人用户标识，匿名或系统操作时为 null。");
+
+                    b.Property<DateTime?>("DeletedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasComment("软删除时间（UTC），未删除时为 null。");
+
+                    b.Property<long?>("DeletedBy")
+                        .HasColumnType("bigint")
+                        .HasComment("删除人用户标识（软删除），未删除时为 null。");
+
+                    b.Property<string>("Description")
+                        .HasMaxLength(512)
+                        .HasColumnType("character varying(512)")
+                        .HasComment("描述信息。");
+
+                    b.Property<long>("GroupId")
+                        .HasColumnType("bigint")
+                        .HasComment("关联分组 ID。");
+
+                    b.Property<bool>("IsDefault")
+                        .HasColumnType("boolean")
+                        .HasComment("是否默认项。");
+
+                    b.Property<bool>("IsEnabled")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("boolean")
+                        .HasDefaultValue(true)
+                        .HasComment("是否启用。");
+
+                    b.Property<string>("Key")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)")
+                        .HasComment("字典项键。");
+
+                    b.Property<int>("SortOrder")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer")
+                        .HasDefaultValue(100)
+                        .HasComment("排序值，越小越靠前。");
+
+                    b.Property<long>("TenantId")
+                        .HasColumnType("bigint")
+                        .HasComment("所属租户 ID。");
+
+                    b.Property<DateTime?>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasComment("最近一次更新时间（UTC），从未更新时为 null。");
+
+                    b.Property<long?>("UpdatedBy")
+                        .HasColumnType("bigint")
+                        .HasComment("最后更新人用户标识，匿名或系统操作时为 null。");
+
+                    b.Property<string>("Value")
+                        .IsRequired()
+                        .HasMaxLength(256)
+                        .HasColumnType("character varying(256)")
+                        .HasComment("字典项值。");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("TenantId");
+
+                    b.HasIndex("GroupId", "Key")
+                        .IsUnique();
+
+                    b.ToTable("dictionary_items", null, t =>
+                        {
+                            t.HasComment("参数字典项。");
+                        });
+                });
+
+            modelBuilder.Entity("TakeoutSaaS.Domain.SystemParameters.Entities.SystemParameter", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasComment("实体唯一标识。");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasComment("创建时间（UTC）。");
+
+                    b.Property<long?>("CreatedBy")
+                        .HasColumnType("bigint")
+                        .HasComment("创建人用户标识，匿名或系统操作时为 null。");
+
+                    b.Property<DateTime?>("DeletedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasComment("软删除时间（UTC），未删除时为 null。");
+
+                    b.Property<long?>("DeletedBy")
+                        .HasColumnType("bigint")
+                        .HasComment("删除人用户标识（软删除），未删除时为 null。");
+
+                    b.Property<string>("Description")
+                        .HasMaxLength(512)
+                        .HasColumnType("character varying(512)")
+                        .HasComment("描述信息。");
+
+                    b.Property<bool>("IsEnabled")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("boolean")
+                        .HasDefaultValue(true)
+                        .HasComment("是否启用。");
+
+                    b.Property<string>("Key")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)")
+                        .HasComment("参数键，租户内唯一。");
+
+                    b.Property<int>("SortOrder")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer")
+                        .HasDefaultValue(100)
+                        .HasComment("排序值，越小越靠前。");
+
+                    b.Property<long>("TenantId")
+                        .HasColumnType("bigint")
+                        .HasComment("所属租户 ID。");
+
+                    b.Property<DateTime?>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasComment("最近一次更新时间（UTC），从未更新时为 null。");
+
+                    b.Property<long?>("UpdatedBy")
+                        .HasColumnType("bigint")
+                        .HasComment("最后更新人用户标识，匿名或系统操作时为 null。");
+
+                    b.Property<string>("Value")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasComment("参数值，支持文本或 JSON。");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("TenantId");
+
+                    b.HasIndex("TenantId", "Key")
+                        .IsUnique();
+
+                    b.ToTable("system_parameters", null, t =>
+                        {
+                            t.HasComment("系统参数实体：支持按租户维护的键值型配置。");
+                        });
+                });
+
+            modelBuilder.Entity("TakeoutSaaS.Domain.Dictionary.Entities.DictionaryItem", b =>
+                {
+                    b.HasOne("TakeoutSaaS.Domain.Dictionary.Entities.DictionaryGroup", "Group")
+                        .WithMany("Items")
+                        .HasForeignKey("GroupId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Group");
+                });
+
+            modelBuilder.Entity("TakeoutSaaS.Domain.Dictionary.Entities.DictionaryGroup", b =>
+                {
+                    b.Navigation("Items");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

src/Infrastructure/TakeoutSaaS.Infrastructure/Migrations/DictionaryDb/20251202043204_AddSystemParametersTable.cs

@@ -0,0 +1,59 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace TakeoutSaaS.Infrastructure.Migrations.DictionaryDb
+{
+    /// <inheritdoc />
+    public partial class AddSystemParametersTable : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "system_parameters",
+                columns: table => new
+                {
+                    Id = table.Column<long>(type: "bigint", nullable: false, comment: "实体唯一标识。")
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    Key = table.Column<string>(type: "character varying(128)", maxLength: 128, nullable: false, comment: "参数键，租户内唯一。"),
+                    Value = table.Column<string>(type: "text", nullable: false, comment: "参数值，支持文本或 JSON。"),
+                    Description = table.Column<string>(type: "character varying(512)", maxLength: 512, nullable: true, comment: "描述信息。"),
+                    SortOrder = table.Column<int>(type: "integer", nullable: false, defaultValue: 100, comment: "排序值，越小越靠前。"),
+                    IsEnabled = table.Column<bool>(type: "boolean", nullable: false, defaultValue: true, comment: "是否启用。"),
+                    CreatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false, comment: "创建时间（UTC）。"),
+                    UpdatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: true, comment: "最近一次更新时间（UTC），从未更新时为 null。"),
+                    DeletedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: true, comment: "软删除时间（UTC），未删除时为 null。"),
+                    CreatedBy = table.Column<long>(type: "bigint", nullable: true, comment: "创建人用户标识，匿名或系统操作时为 null。"),
+                    UpdatedBy = table.Column<long>(type: "bigint", nullable: true, comment: "最后更新人用户标识，匿名或系统操作时为 null。"),
+                    DeletedBy = table.Column<long>(type: "bigint", nullable: true, comment: "删除人用户标识（软删除），未删除时为 null。"),
+                    TenantId = table.Column<long>(type: "bigint", nullable: false, comment: "所属租户 ID。")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_system_parameters", x => x.Id);
+                },
+                comment: "系统参数实体：支持按租户维护的键值型配置。");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_system_parameters_TenantId",
+                table: "system_parameters",
+                column: "TenantId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_system_parameters_TenantId_Key",
+                table: "system_parameters",
+                columns: new[] { "TenantId", "Key" },
+                unique: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "system_parameters");
+        }
+    }
+}

src/Infrastructure/TakeoutSaaS.Infrastructure/Migrations/DictionaryDb/DictionaryDbContextModelSnapshot.cs

@@ -186,6 +186,84 @@ namespace TakeoutSaaS.Infrastructure.Migrations.DictionaryDb
                         });
                 });
 
+            modelBuilder.Entity("TakeoutSaaS.Domain.SystemParameters.Entities.SystemParameter", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasComment("实体唯一标识。");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasComment("创建时间（UTC）。");
+
+                    b.Property<long?>("CreatedBy")
+                        .HasColumnType("bigint")
+                        .HasComment("创建人用户标识，匿名或系统操作时为 null。");
+
+                    b.Property<DateTime?>("DeletedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasComment("软删除时间（UTC），未删除时为 null。");
+
+                    b.Property<long?>("DeletedBy")
+                        .HasColumnType("bigint")
+                        .HasComment("删除人用户标识（软删除），未删除时为 null。");
+
+                    b.Property<string>("Description")
+                        .HasMaxLength(512)
+                        .HasColumnType("character varying(512)")
+                        .HasComment("描述信息。");
+
+                    b.Property<bool>("IsEnabled")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("boolean")
+                        .HasDefaultValue(true)
+                        .HasComment("是否启用。");
+
+                    b.Property<string>("Key")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("character varying(128)")
+                        .HasComment("参数键，租户内唯一。");
+
+                    b.Property<int>("SortOrder")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer")
+                        .HasDefaultValue(100)
+                        .HasComment("排序值，越小越靠前。");
+
+                    b.Property<long>("TenantId")
+                        .HasColumnType("bigint")
+                        .HasComment("所属租户 ID。");
+
+                    b.Property<DateTime?>("UpdatedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasComment("最近一次更新时间（UTC），从未更新时为 null。");
+
+                    b.Property<long?>("UpdatedBy")
+                        .HasColumnType("bigint")
+                        .HasComment("最后更新人用户标识，匿名或系统操作时为 null。");
+
+                    b.Property<string>("Value")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasComment("参数值，支持文本或 JSON。");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("TenantId");
+
+                    b.HasIndex("TenantId", "Key")
+                        .IsUnique();
+
+                    b.ToTable("system_parameters", null, t =>
+                        {
+                            t.HasComment("系统参数实体：支持按租户维护的键值型配置。");
+                        });
+                });
+
             modelBuilder.Entity("TakeoutSaaS.Domain.Dictionary.Entities.DictionaryItem", b =>
                 {
                     b.HasOne("TakeoutSaaS.Domain.Dictionary.Entities.DictionaryGroup", "Group")