[CLAUDE] Domain+App+Api: Module Ngan sach (Budget) - 4 bang + workflow simple

User request: 'Them cho tao 4 bang luu ve ngan sach: Header / Chi tiet
/ Quy trinh duyet / Lich su thay doi'.

Domain (5 file + 1 enum):
 - Budget (header) — Aggregate root, AuditableEntity. Field: MaNganSach,
   TenNganSach, Description, NamNganSach, ProjectId FK, DepartmentId?,
   DrafterUserId, Phase (BudgetPhase 5-state), TongNganSach (sum auto
   tu Details), SlaDeadline, SlaWarningSent.
 - BudgetDetail — flat row pattern (GroupCode/GroupName + Item +
   KhoiLuong/DonGia/ThanhTien). 18,4 precision KhoiLuong, 18,2 money.
 - BudgetApproval — workflow history (FromPhase/ToPhase/Decision/Comment)
 - BudgetChangelog — audit log unified (EntityType: Header/Detail/Workflow)
 - BudgetPhase enum 5 state: DangSoanThao(1) → ChoCCM(2) → ChoCEO(3) →
   DaDuyet(4) | TuChoi(99)
 - BudgetPolicy hardcoded (no versioned WF, simple default per user
   confirm 'tam thoi don gian'): Drafter/DeptManager → CCM → CEO/
   AuthorizedSigner. Reject path back to DangSoanThao.

Migration 14 AddBudgets:
 - 4 bang moi: Budgets + BudgetDetails + BudgetApprovals + BudgetChangelogs
 - Index: Phase+IsDeleted, ProjectId, NamNganSach, SlaDeadline,
   MaNganSach unique filtered. Cascade delete child.
 - +2 cot FK ngoai bang (per user 'lien ket ca 3'):
   * Contracts.BudgetId Guid? + index
   * PurchaseEvaluations.BudgetId Guid? + index
   Cho phep doi chieu chi phi HD/PE vs ngan sach goi thau.

Application CQRS (BudgetFeatures.cs ~340 line):
 - CreateBudget + UpdateBudgetDraft + TransitionBudget + ListBudgets
   (filter Phase/Project/Year + search + paging) + GetBudget bundle
   (Header + Details + Approvals + Workflow summary)
 - DeleteBudget (only DangSoanThao/TuChoi)
 - AddBudgetDetail + UpdateBudgetDetail + DeleteBudgetDetail (auto
   recompute TongNganSach = sum Details.ThanhTien)
 - ListBudgetChangelogs

Api: BudgetsController 11 endpoint REST /api/budgets:
 - GET /  /{id}  /{id}/changelogs
 - POST /  /{id}/transitions  /{id}/details
 - PUT /{id}  /{id}/details/{detailId}
 - DELETE /{id}  /{id}/details/{detailId}

DbContext + IApplicationDbContext: 4 DbSet new (Budgets/Details/
Approvals/Changelogs).

MenuKeys + DbInitializer: 4 menu key (Budgets root + Bg_List/Create/
Pending leaves) seed dau order=27 'Ngan sach' icon Wallet. Auto-grant
admin permission via SeedAdminPermissionsAsync (MenuKeys.All).

MaNganSach format don gian 'NS-YYYYMM-NNNN' Random.Shared (chua atomic
sequence - user said 'tam thoi chua co').

Workflow chua versioned, hardcode BudgetPolicy.Default. Tuong lai admin
config qua UI: them BudgetWorkflowDefinition tables tuong tu PE.

src/Backend/SolutionErp.Infrastructure/Persistence/ApplicationDbContext.cs

@@ -1,6 +1,7 @@
 using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore;
 using SolutionErp.Application.Common.Interfaces;
+using SolutionErp.Domain.Budgets;
 using SolutionErp.Domain.Contracts;
 using SolutionErp.Domain.Contracts.Details;
 using SolutionErp.Domain.Forms;
@@ -59,6 +60,12 @@ public class ApplicationDbContext
     public DbSet<PurchaseEvaluationWorkflowStepApprover> PurchaseEvaluationWorkflowStepApprovers => Set<PurchaseEvaluationWorkflowStepApprover>();
     public DbSet<PurchaseEvaluationCodeSequence> PurchaseEvaluationCodeSequences => Set<PurchaseEvaluationCodeSequence>();
 
+    // Module Ngân sách (Phase 7) — 4 bảng: Budget header + Details + Approvals + Changelogs.
+    public DbSet<Budget> Budgets => Set<Budget>();
+    public DbSet<BudgetDetail> BudgetDetails => Set<BudgetDetail>();
+    public DbSet<BudgetApproval> BudgetApprovals => Set<BudgetApproval>();
+    public DbSet<BudgetChangelog> BudgetChangelogs => Set<BudgetChangelog>();
+
     protected override void OnModelCreating(ModelBuilder builder)
     {
         base.OnModelCreating(builder);

src/Backend/SolutionErp.Infrastructure/Persistence/Configurations/BudgetConfiguration.cs

@@ -0,0 +1,89 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+using SolutionErp.Domain.Budgets;
+
+namespace SolutionErp.Infrastructure.Persistence.Configurations;
+
+public class BudgetConfiguration : IEntityTypeConfiguration<Budget>
+{
+    public void Configure(EntityTypeBuilder<Budget> b)
+    {
+        b.ToTable("Budgets");
+        b.HasKey(x => x.Id);
+
+        b.Property(x => x.MaNganSach).HasMaxLength(100);
+        b.Property(x => x.TenNganSach).HasMaxLength(500).IsRequired();
+        b.Property(x => x.Description).HasMaxLength(2000);
+        b.Property(x => x.Phase).HasConversion<int>();
+        b.Property(x => x.TongNganSach).HasPrecision(18, 2);
+
+        b.HasIndex(x => x.MaNganSach).IsUnique().HasFilter("[MaNganSach] IS NOT NULL");
+        b.HasIndex(x => new { x.Phase, x.IsDeleted });
+        b.HasIndex(x => x.ProjectId);
+        b.HasIndex(x => x.NamNganSach);
+        b.HasIndex(x => x.SlaDeadline);
+
+        b.HasMany(x => x.Details).WithOne(d => d.Budget).HasForeignKey(d => d.BudgetId).OnDelete(DeleteBehavior.Cascade);
+        b.HasMany(x => x.Approvals).WithOne(a => a.Budget).HasForeignKey(a => a.BudgetId).OnDelete(DeleteBehavior.Cascade);
+        b.HasMany(x => x.Changelogs).WithOne(c => c.Budget).HasForeignKey(c => c.BudgetId).OnDelete(DeleteBehavior.Cascade);
+
+        b.HasQueryFilter(x => !x.IsDeleted);
+    }
+}
+
+public class BudgetDetailConfiguration : IEntityTypeConfiguration<BudgetDetail>
+{
+    public void Configure(EntityTypeBuilder<BudgetDetail> b)
+    {
+        b.ToTable("BudgetDetails");
+        b.HasKey(x => x.Id);
+
+        b.Property(x => x.GroupCode).HasMaxLength(50).IsRequired();
+        b.Property(x => x.GroupName).HasMaxLength(200).IsRequired();
+        b.Property(x => x.ItemCode).HasMaxLength(100);
+        b.Property(x => x.NoiDung).HasMaxLength(500).IsRequired();
+        b.Property(x => x.DonViTinh).HasMaxLength(50);
+        b.Property(x => x.GhiChu).HasMaxLength(1000);
+        b.Property(x => x.KhoiLuong).HasPrecision(18, 4);
+        b.Property(x => x.DonGia).HasPrecision(18, 2);
+        b.Property(x => x.ThanhTien).HasPrecision(18, 2);
+
+        b.HasIndex(x => new { x.BudgetId, x.Order });
+    }
+}
+
+public class BudgetApprovalConfiguration : IEntityTypeConfiguration<BudgetApproval>
+{
+    public void Configure(EntityTypeBuilder<BudgetApproval> b)
+    {
+        b.ToTable("BudgetApprovals");
+        b.HasKey(x => x.Id);
+
+        b.Property(x => x.FromPhase).HasConversion<int>();
+        b.Property(x => x.ToPhase).HasConversion<int>();
+        b.Property(x => x.Decision).HasConversion<int>();
+        b.Property(x => x.Comment).HasMaxLength(1000);
+
+        b.HasIndex(x => new { x.BudgetId, x.ApprovedAt });
+    }
+}
+
+public class BudgetChangelogConfiguration : IEntityTypeConfiguration<BudgetChangelog>
+{
+    public void Configure(EntityTypeBuilder<BudgetChangelog> b)
+    {
+        b.ToTable("BudgetChangelogs");
+        b.HasKey(x => x.Id);
+
+        b.Property(x => x.EntityType).HasConversion<int>();
+        b.Property(x => x.Action).HasConversion<int>();
+        b.Property(x => x.PhaseAtChange).HasConversion<int>();
+        b.Property(x => x.UserName).HasMaxLength(200);
+        b.Property(x => x.Summary).HasMaxLength(500);
+        b.Property(x => x.ContextNote).HasMaxLength(2000);
+        b.Property(x => x.FieldChangesJson).HasColumnType("nvarchar(max)");
+
+        b.HasIndex(x => new { x.BudgetId, x.CreatedAt });
+        b.HasIndex(x => new { x.BudgetId, x.EntityType });
+    }
+}

src/Backend/SolutionErp.Infrastructure/Persistence/Configurations/ContractConfiguration.cs

@@ -24,6 +24,7 @@ public class ContractConfiguration : IEntityTypeConfiguration<Contract>
         b.HasIndex(x => x.SupplierId);
         b.HasIndex(x => x.ProjectId);
         b.HasIndex(x => x.SlaDeadline);
+        b.HasIndex(x => x.BudgetId);
 
         b.HasMany(x => x.Approvals).WithOne(a => a.Contract).HasForeignKey(a => a.ContractId).OnDelete(DeleteBehavior.Cascade);
         b.HasMany(x => x.Comments).WithOne(c => c.Contract).HasForeignKey(c => c.ContractId).OnDelete(DeleteBehavior.Cascade);

src/Backend/SolutionErp.Infrastructure/Persistence/Configurations/PurchaseEvaluationConfiguration.cs

@@ -25,6 +25,7 @@ public class PurchaseEvaluationConfiguration : IEntityTypeConfiguration<Purchase
         b.HasIndex(x => x.SlaDeadline);
         b.HasIndex(x => x.WorkflowDefinitionId);
         b.HasIndex(x => x.ContractId);
+        b.HasIndex(x => x.BudgetId);
 
         b.HasMany(x => x.Suppliers).WithOne(s => s.PurchaseEvaluation).HasForeignKey(s => s.PurchaseEvaluationId).OnDelete(DeleteBehavior.Cascade);
         b.HasMany(x => x.Details).WithOne(d => d.PurchaseEvaluation).HasForeignKey(d => d.PurchaseEvaluationId).OnDelete(DeleteBehavior.Cascade);

src/Backend/SolutionErp.Infrastructure/Persistence/DbInitializer.cs

@@ -1308,6 +1308,11 @@ public static class DbInitializer
             // Module Duyệt NCC (tiền-HĐ)
             (MenuKeys.PurchaseEvaluations, "Quy trình chọn Thầu phụ - NCC", null, 25, "ClipboardCheck"),
             (MenuKeys.PeWorkflows,         "Quy trình Duyệt NCC",           MenuKeys.System,  95, "GitCompareArrows"),
+            // Module Ngân sách (Phase 7)
+            (MenuKeys.Budgets,       "Ngân sách",           null,            27, "Wallet"),
+            (MenuKeys.BudgetList,    "Danh sách",           MenuKeys.Budgets, 1, "List"),
+            (MenuKeys.BudgetCreate,  "Thao tác",            MenuKeys.Budgets, 2, "Plus"),
+            (MenuKeys.BudgetPending, "Duyệt",               MenuKeys.Budgets, 3, "CheckCircle2"),
         };
 
         // Per-type sub-menu under Contracts: 1 group + 3 leaves each

src/Backend/SolutionErp.Infrastructure/Persistence/Migrations/20260428043508_AddBudgets.cs

@@ -0,0 +1,236 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace SolutionErp.Infrastructure.Persistence.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddBudgets : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<Guid>(
+                name: "BudgetId",
+                table: "PurchaseEvaluations",
+                type: "uniqueidentifier",
+                nullable: true);
+
+            migrationBuilder.AddColumn<Guid>(
+                name: "BudgetId",
+                table: "Contracts",
+                type: "uniqueidentifier",
+                nullable: true);
+
+            migrationBuilder.CreateTable(
+                name: "Budgets",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "uniqueidentifier", nullable: false),
+                    MaNganSach = table.Column<string>(type: "nvarchar(100)", maxLength: 100, nullable: true),
+                    TenNganSach = table.Column<string>(type: "nvarchar(500)", maxLength: 500, nullable: false),
+                    Description = table.Column<string>(type: "nvarchar(2000)", maxLength: 2000, nullable: true),
+                    NamNganSach = table.Column<int>(type: "int", nullable: false),
+                    ProjectId = table.Column<Guid>(type: "uniqueidentifier", nullable: false),
+                    DepartmentId = table.Column<Guid>(type: "uniqueidentifier", nullable: true),
+                    DrafterUserId = table.Column<Guid>(type: "uniqueidentifier", nullable: true),
+                    Phase = table.Column<int>(type: "int", nullable: false),
+                    TongNganSach = table.Column<decimal>(type: "decimal(18,2)", precision: 18, scale: 2, nullable: false),
+                    SlaDeadline = table.Column<DateTime>(type: "datetime2", nullable: true),
+                    SlaWarningSent = table.Column<bool>(type: "bit", nullable: false),
+                    CreatedAt = table.Column<DateTime>(type: "datetime2", nullable: false),
+                    UpdatedAt = table.Column<DateTime>(type: "datetime2", nullable: true),
+                    CreatedBy = table.Column<Guid>(type: "uniqueidentifier", nullable: true),
+                    UpdatedBy = table.Column<Guid>(type: "uniqueidentifier", nullable: true),
+                    IsDeleted = table.Column<bool>(type: "bit", nullable: false),
+                    DeletedAt = table.Column<DateTime>(type: "datetime2", nullable: true),
+                    DeletedBy = table.Column<Guid>(type: "uniqueidentifier", nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Budgets", x => x.Id);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "BudgetApprovals",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "uniqueidentifier", nullable: false),
+                    BudgetId = table.Column<Guid>(type: "uniqueidentifier", nullable: false),
+                    FromPhase = table.Column<int>(type: "int", nullable: false),
+                    ToPhase = table.Column<int>(type: "int", nullable: false),
+                    ApproverUserId = table.Column<Guid>(type: "uniqueidentifier", nullable: true),
+                    Decision = table.Column<int>(type: "int", nullable: false),
+                    Comment = table.Column<string>(type: "nvarchar(1000)", maxLength: 1000, nullable: true),
+                    ApprovedAt = table.Column<DateTime>(type: "datetime2", nullable: false),
+                    CreatedAt = table.Column<DateTime>(type: "datetime2", nullable: false),
+                    UpdatedAt = table.Column<DateTime>(type: "datetime2", nullable: true),
+                    CreatedBy = table.Column<Guid>(type: "uniqueidentifier", nullable: true),
+                    UpdatedBy = table.Column<Guid>(type: "uniqueidentifier", nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_BudgetApprovals", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_BudgetApprovals_Budgets_BudgetId",
+                        column: x => x.BudgetId,
+                        principalTable: "Budgets",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "BudgetChangelogs",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "uniqueidentifier", nullable: false),
+                    BudgetId = table.Column<Guid>(type: "uniqueidentifier", nullable: false),
+                    EntityType = table.Column<int>(type: "int", nullable: false),
+                    EntityId = table.Column<Guid>(type: "uniqueidentifier", nullable: true),
+                    Action = table.Column<int>(type: "int", nullable: false),
+                    PhaseAtChange = table.Column<int>(type: "int", nullable: true),
+                    UserId = table.Column<Guid>(type: "uniqueidentifier", nullable: true),
+                    UserName = table.Column<string>(type: "nvarchar(200)", maxLength: 200, nullable: true),
+                    Summary = table.Column<string>(type: "nvarchar(500)", maxLength: 500, nullable: true),
+                    FieldChangesJson = table.Column<string>(type: "nvarchar(max)", nullable: true),
+                    ContextNote = table.Column<string>(type: "nvarchar(2000)", maxLength: 2000, nullable: true),
+                    CreatedAt = table.Column<DateTime>(type: "datetime2", nullable: false),
+                    UpdatedAt = table.Column<DateTime>(type: "datetime2", nullable: true),
+                    CreatedBy = table.Column<Guid>(type: "uniqueidentifier", nullable: true),
+                    UpdatedBy = table.Column<Guid>(type: "uniqueidentifier", nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_BudgetChangelogs", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_BudgetChangelogs_Budgets_BudgetId",
+                        column: x => x.BudgetId,
+                        principalTable: "Budgets",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "BudgetDetails",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "uniqueidentifier", nullable: false),
+                    BudgetId = table.Column<Guid>(type: "uniqueidentifier", nullable: false),
+                    GroupCode = table.Column<string>(type: "nvarchar(50)", maxLength: 50, nullable: false),
+                    GroupName = table.Column<string>(type: "nvarchar(200)", maxLength: 200, nullable: false),
+                    ItemCode = table.Column<string>(type: "nvarchar(100)", maxLength: 100, nullable: true),
+                    NoiDung = table.Column<string>(type: "nvarchar(500)", maxLength: 500, nullable: false),
+                    DonViTinh = table.Column<string>(type: "nvarchar(50)", maxLength: 50, nullable: true),
+                    KhoiLuong = table.Column<decimal>(type: "decimal(18,4)", precision: 18, scale: 4, nullable: false),
+                    DonGia = table.Column<decimal>(type: "decimal(18,2)", precision: 18, scale: 2, nullable: false),
+                    ThanhTien = table.Column<decimal>(type: "decimal(18,2)", precision: 18, scale: 2, nullable: false),
+                    Order = table.Column<int>(type: "int", nullable: false),
+                    GhiChu = table.Column<string>(type: "nvarchar(1000)", maxLength: 1000, nullable: true),
+                    CreatedAt = table.Column<DateTime>(type: "datetime2", nullable: false),
+                    UpdatedAt = table.Column<DateTime>(type: "datetime2", nullable: true),
+                    CreatedBy = table.Column<Guid>(type: "uniqueidentifier", nullable: true),
+                    UpdatedBy = table.Column<Guid>(type: "uniqueidentifier", nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_BudgetDetails", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_BudgetDetails_Budgets_BudgetId",
+                        column: x => x.BudgetId,
+                        principalTable: "Budgets",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_PurchaseEvaluations_BudgetId",
+                table: "PurchaseEvaluations",
+                column: "BudgetId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Contracts_BudgetId",
+                table: "Contracts",
+                column: "BudgetId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_BudgetApprovals_BudgetId_ApprovedAt",
+                table: "BudgetApprovals",
+                columns: new[] { "BudgetId", "ApprovedAt" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_BudgetChangelogs_BudgetId_CreatedAt",
+                table: "BudgetChangelogs",
+                columns: new[] { "BudgetId", "CreatedAt" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_BudgetChangelogs_BudgetId_EntityType",
+                table: "BudgetChangelogs",
+                columns: new[] { "BudgetId", "EntityType" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_BudgetDetails_BudgetId_Order",
+                table: "BudgetDetails",
+                columns: new[] { "BudgetId", "Order" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Budgets_MaNganSach",
+                table: "Budgets",
+                column: "MaNganSach",
+                unique: true,
+                filter: "[MaNganSach] IS NOT NULL");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Budgets_NamNganSach",
+                table: "Budgets",
+                column: "NamNganSach");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Budgets_Phase_IsDeleted",
+                table: "Budgets",
+                columns: new[] { "Phase", "IsDeleted" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Budgets_ProjectId",
+                table: "Budgets",
+                column: "ProjectId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Budgets_SlaDeadline",
+                table: "Budgets",
+                column: "SlaDeadline");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "BudgetApprovals");
+
+            migrationBuilder.DropTable(
+                name: "BudgetChangelogs");
+
+            migrationBuilder.DropTable(
+                name: "BudgetDetails");
+
+            migrationBuilder.DropTable(
+                name: "Budgets");
+
+            migrationBuilder.DropIndex(
+                name: "IX_PurchaseEvaluations_BudgetId",
+                table: "PurchaseEvaluations");
+
+            migrationBuilder.DropIndex(
+                name: "IX_Contracts_BudgetId",
+                table: "Contracts");
+
+            migrationBuilder.DropColumn(
+                name: "BudgetId",
+                table: "PurchaseEvaluations");
+
+            migrationBuilder.DropColumn(
+                name: "BudgetId",
+                table: "Contracts");
+        }
+    }
+}

src/Backend/SolutionErp.Infrastructure/Persistence/Migrations/ApplicationDbContextModelSnapshot.cs

@@ -125,12 +125,274 @@ namespace SolutionErp.Infrastructure.Persistence.Migrations
                     b.ToTable("UserTokens", (string)null);
                 });
 
+            modelBuilder.Entity("SolutionErp.Domain.Budgets.Budget", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<Guid?>("CreatedBy")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<DateTime?>("DeletedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<Guid?>("DeletedBy")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<Guid?>("DepartmentId")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<string>("Description")
+                        .HasMaxLength(2000)
+                        .HasColumnType("nvarchar(2000)");
+
+                    b.Property<Guid?>("DrafterUserId")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<bool>("IsDeleted")
+                        .HasColumnType("bit");
+
+                    b.Property<string>("MaNganSach")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<int>("NamNganSach")
+                        .HasColumnType("int");
+
+                    b.Property<int>("Phase")
+                        .HasColumnType("int");
+
+                    b.Property<Guid>("ProjectId")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<DateTime?>("SlaDeadline")
+                        .HasColumnType("datetime2");
+
+                    b.Property<bool>("SlaWarningSent")
+                        .HasColumnType("bit");
+
+                    b.Property<string>("TenNganSach")
+                        .IsRequired()
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<decimal>("TongNganSach")
+                        .HasPrecision(18, 2)
+                        .HasColumnType("decimal(18,2)");
+
+                    b.Property<DateTime?>("UpdatedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<Guid?>("UpdatedBy")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("MaNganSach")
+                        .IsUnique()
+                        .HasFilter("[MaNganSach] IS NOT NULL");
+
+                    b.HasIndex("NamNganSach");
+
+                    b.HasIndex("ProjectId");
+
+                    b.HasIndex("SlaDeadline");
+
+                    b.HasIndex("Phase", "IsDeleted");
+
+                    b.ToTable("Budgets", (string)null);
+                });
+
+            modelBuilder.Entity("SolutionErp.Domain.Budgets.BudgetApproval", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<DateTime>("ApprovedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<Guid?>("ApproverUserId")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<Guid>("BudgetId")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<string>("Comment")
+                        .HasMaxLength(1000)
+                        .HasColumnType("nvarchar(1000)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<Guid?>("CreatedBy")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<int>("Decision")
+                        .HasColumnType("int");
+
+                    b.Property<int>("FromPhase")
+                        .HasColumnType("int");
+
+                    b.Property<int>("ToPhase")
+                        .HasColumnType("int");
+
+                    b.Property<DateTime?>("UpdatedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<Guid?>("UpdatedBy")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("BudgetId", "ApprovedAt");
+
+                    b.ToTable("BudgetApprovals", (string)null);
+                });
+
+            modelBuilder.Entity("SolutionErp.Domain.Budgets.BudgetChangelog", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<int>("Action")
+                        .HasColumnType("int");
+
+                    b.Property<Guid>("BudgetId")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<string>("ContextNote")
+                        .HasMaxLength(2000)
+                        .HasColumnType("nvarchar(2000)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<Guid?>("CreatedBy")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<Guid?>("EntityId")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<int>("EntityType")
+                        .HasColumnType("int");
+
+                    b.Property<string>("FieldChangesJson")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<int?>("PhaseAtChange")
+                        .HasColumnType("int");
+
+                    b.Property<string>("Summary")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<DateTime?>("UpdatedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<Guid?>("UpdatedBy")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<Guid?>("UserId")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<string>("UserName")
+                        .HasMaxLength(200)
+                        .HasColumnType("nvarchar(200)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("BudgetId", "CreatedAt");
+
+                    b.HasIndex("BudgetId", "EntityType");
+
+                    b.ToTable("BudgetChangelogs", (string)null);
+                });
+
+            modelBuilder.Entity("SolutionErp.Domain.Budgets.BudgetDetail", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<Guid>("BudgetId")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<Guid?>("CreatedBy")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.Property<decimal>("DonGia")
+                        .HasPrecision(18, 2)
+                        .HasColumnType("decimal(18,2)");
+
+                    b.Property<string>("DonViTinh")
+                        .HasMaxLength(50)
+                        .HasColumnType("nvarchar(50)");
+
+                    b.Property<string>("GhiChu")
+                        .HasMaxLength(1000)
+                        .HasColumnType("nvarchar(1000)");
+
+                    b.Property<string>("GroupCode")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("nvarchar(50)");
+
+                    b.Property<string>("GroupName")
+                        .IsRequired()
+                        .HasMaxLength(200)
+                        .HasColumnType("nvarchar(200)");
+
+                    b.Property<string>("ItemCode")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<decimal>("KhoiLuong")
+                        .HasPrecision(18, 4)
+                        .HasColumnType("decimal(18,4)");
+
+                    b.Property<string>("NoiDung")
+                        .IsRequired()
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<int>("Order")
+                        .HasColumnType("int");
+
+                    b.Property<decimal>("ThanhTien")
+                        .HasPrecision(18, 2)
+                        .HasColumnType("decimal(18,2)");
+
+                    b.Property<DateTime?>("UpdatedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<Guid?>("UpdatedBy")
+                        .HasColumnType("uniqueidentifier");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("BudgetId", "Order");
+
+                    b.ToTable("BudgetDetails", (string)null);
+                });
+
             modelBuilder.Entity("SolutionErp.Domain.Contracts.Contract", b =>
                 {
                     b.Property<Guid>("Id")
                         .ValueGeneratedOnAdd()
                         .HasColumnType("uniqueidentifier");
 
+                    b.Property<Guid?>("BudgetId")
+                        .HasColumnType("uniqueidentifier");
+
                     b.Property<bool>("BypassProcurementAndCCM")
                         .HasColumnType("bit");
 
@@ -206,6 +468,8 @@ namespace SolutionErp.Infrastructure.Persistence.Migrations
 
                     b.HasKey("Id");
 
+                    b.HasIndex("BudgetId");
+
                     b.HasIndex("MaHopDong")
                         .IsUnique()
                         .HasFilter("[MaHopDong] IS NOT NULL");
@@ -1910,6 +2174,9 @@ namespace SolutionErp.Infrastructure.Persistence.Migrations
                         .ValueGeneratedOnAdd()
                         .HasColumnType("uniqueidentifier");
 
+                    b.Property<Guid?>("BudgetId")
+                        .HasColumnType("uniqueidentifier");
+
                     b.Property<Guid?>("ContractId")
                         .HasColumnType("uniqueidentifier");
 
@@ -1983,6 +2250,8 @@ namespace SolutionErp.Infrastructure.Persistence.Migrations
 
                     b.HasKey("Id");
 
+                    b.HasIndex("BudgetId");
+
                     b.HasIndex("ContractId");
 
                     b.HasIndex("MaPhieu")
@@ -2558,6 +2827,39 @@ namespace SolutionErp.Infrastructure.Persistence.Migrations
                         .IsRequired();
                 });
 
+            modelBuilder.Entity("SolutionErp.Domain.Budgets.BudgetApproval", b =>
+                {
+                    b.HasOne("SolutionErp.Domain.Budgets.Budget", "Budget")
+                        .WithMany("Approvals")
+                        .HasForeignKey("BudgetId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Budget");
+                });
+
+            modelBuilder.Entity("SolutionErp.Domain.Budgets.BudgetChangelog", b =>
+                {
+                    b.HasOne("SolutionErp.Domain.Budgets.Budget", "Budget")
+                        .WithMany("Changelogs")
+                        .HasForeignKey("BudgetId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Budget");
+                });
+
+            modelBuilder.Entity("SolutionErp.Domain.Budgets.BudgetDetail", b =>
+                {
+                    b.HasOne("SolutionErp.Domain.Budgets.Budget", "Budget")
+                        .WithMany("Details")
+                        .HasForeignKey("BudgetId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Budget");
+                });
+
             modelBuilder.Entity("SolutionErp.Domain.Contracts.ContractApproval", b =>
                 {
                     b.HasOne("SolutionErp.Domain.Contracts.Contract", "Contract")
@@ -2838,6 +3140,15 @@ namespace SolutionErp.Infrastructure.Persistence.Migrations
                     b.Navigation("Step");
                 });
 
+            modelBuilder.Entity("SolutionErp.Domain.Budgets.Budget", b =>
+                {
+                    b.Navigation("Approvals");
+
+                    b.Navigation("Changelogs");
+
+                    b.Navigation("Details");
+                });
+
             modelBuilder.Entity("SolutionErp.Domain.Contracts.Contract", b =>
                 {
                     b.Navigation("Approvals");