[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.Application/Budgets/BudgetFeatures.cs

@@ -0,0 +1,388 @@
+using FluentValidation;
+using MediatR;
+using Microsoft.AspNetCore.Identity;
+using Microsoft.EntityFrameworkCore;
+using SolutionErp.Application.Budgets.Dtos;
+using SolutionErp.Application.Common.Exceptions;
+using SolutionErp.Application.Common.Interfaces;
+using SolutionErp.Application.Common.Models;
+using SolutionErp.Domain.Budgets;
+using SolutionErp.Domain.Contracts;   // ApprovalDecision + ChangelogAction
+using SolutionErp.Domain.Identity;
+
+namespace SolutionErp.Application.Budgets;
+
+// Compact CQRS feature file cho module Ngân sách. Pattern simplified vs PE
+// (no versioned WF, hardcoded BudgetPolicy.Default). Workflow 5 phase:
+// DangSoanThao → ChoCCM → ChoCEO → DaDuyet/TuChoi.
+
+// ========== CREATE ==========
+
+public record CreateBudgetCommand(
+    string TenNganSach,
+    string? Description,
+    int NamNganSach,
+    Guid ProjectId,
+    Guid? DepartmentId) : IRequest<Guid>;
+
+public class CreateBudgetCommandValidator : AbstractValidator<CreateBudgetCommand>
+{
+    public CreateBudgetCommandValidator()
+    {
+        RuleFor(x => x.TenNganSach).NotEmpty().MaximumLength(500);
+        RuleFor(x => x.Description).MaximumLength(2000);
+        RuleFor(x => x.ProjectId).NotEmpty();
+        RuleFor(x => x.NamNganSach).InclusiveBetween(2020, 2100);
+    }
+}
+
+public class CreateBudgetCommandHandler(
+    IApplicationDbContext db,
+    ICurrentUser currentUser) : IRequestHandler<CreateBudgetCommand, Guid>
+{
+    public async Task<Guid> Handle(CreateBudgetCommand request, CancellationToken ct)
+    {
+        _ = await db.Projects.FirstOrDefaultAsync(p => p.Id == request.ProjectId, ct)
+            ?? throw new NotFoundException("Project", request.ProjectId);
+
+        var sla = BudgetPolicies.Default.PhaseSla.GetValueOrDefault(BudgetPhase.DangSoanThao);
+        var entity = new Budget
+        {
+            TenNganSach = request.TenNganSach,
+            Description = request.Description,
+            NamNganSach = request.NamNganSach,
+            ProjectId = request.ProjectId,
+            DepartmentId = request.DepartmentId,
+            DrafterUserId = currentUser.UserId,
+            Phase = BudgetPhase.DangSoanThao,
+            TongNganSach = 0,
+            SlaDeadline = sla is null ? null : DateTime.UtcNow.Add(sla.Value),
+            // Auto-gen MaNganSach đơn giản — atomic sequence sau (Phase 8)
+            MaNganSach = $"NS-{DateTime.UtcNow:yyyyMM}-{Random.Shared.Next(1000, 9999)}",
+        };
+        db.Budgets.Add(entity);
+
+        db.BudgetChangelogs.Add(new BudgetChangelog
+        {
+            BudgetId = entity.Id,
+            EntityType = BudgetEntityType.Header,
+            Action = ChangelogAction.Insert,
+            PhaseAtChange = entity.Phase,
+            UserId = currentUser.UserId,
+            Summary = $"Tạo ngân sách {entity.MaNganSach} — {entity.TenNganSach}",
+        });
+
+        await db.SaveChangesAsync(ct);
+        return entity.Id;
+    }
+}
+
+// ========== UPDATE draft ==========
+
+public record UpdateBudgetDraftCommand(
+    Guid Id,
+    string TenNganSach,
+    string? Description,
+    int NamNganSach) : IRequest;
+
+public class UpdateBudgetDraftCommandHandler(
+    IApplicationDbContext db,
+    ICurrentUser currentUser) : IRequestHandler<UpdateBudgetDraftCommand>
+{
+    public async Task Handle(UpdateBudgetDraftCommand request, CancellationToken ct)
+    {
+        var entity = await db.Budgets.FirstOrDefaultAsync(x => x.Id == request.Id, ct)
+            ?? throw new NotFoundException("Budget", request.Id);
+        if (entity.Phase != BudgetPhase.DangSoanThao)
+            throw new ConflictException("Chỉ sửa được ngân sách khi Đang soạn thảo.");
+
+        entity.TenNganSach = request.TenNganSach;
+        entity.Description = request.Description;
+        entity.NamNganSach = request.NamNganSach;
+
+        db.BudgetChangelogs.Add(new BudgetChangelog
+        {
+            BudgetId = entity.Id,
+            EntityType = BudgetEntityType.Header,
+            Action = ChangelogAction.Update,
+            PhaseAtChange = entity.Phase,
+            UserId = currentUser.UserId,
+            Summary = "Cập nhật ngân sách",
+        });
+        await db.SaveChangesAsync(ct);
+    }
+}
+
+// ========== TRANSITION ==========
+
+public record TransitionBudgetCommand(
+    Guid Id, BudgetPhase TargetPhase, ApprovalDecision Decision, string? Comment) : IRequest;
+
+public class TransitionBudgetCommandHandler(
+    IApplicationDbContext db,
+    ICurrentUser currentUser,
+    UserManager<User> userManager) : IRequestHandler<TransitionBudgetCommand>
+{
+    public async Task Handle(TransitionBudgetCommand request, CancellationToken ct)
+    {
+        if (!currentUser.IsAuthenticated || currentUser.UserId is null)
+            throw new UnauthorizedException();
+
+        var entity = await db.Budgets.FirstOrDefaultAsync(x => x.Id == request.Id, ct)
+            ?? throw new NotFoundException("Budget", request.Id);
+
+        var policy = BudgetPolicies.Default;
+        var isAdmin = currentUser.Roles.Contains(AppRoles.Admin);
+
+        if (!isAdmin && !policy.IsTransitionAllowed(entity.Phase, request.TargetPhase, currentUser.Roles))
+            throw new ForbiddenException(
+                $"Role không đủ quyền chuyển {entity.Phase} → {request.TargetPhase}.");
+
+        var fromPhase = entity.Phase;
+        entity.SlaWarningSent = false;
+        entity.Phase = request.TargetPhase;
+        var sla = policy.PhaseSla.GetValueOrDefault(request.TargetPhase);
+        entity.SlaDeadline = sla is null ? null : DateTime.UtcNow.Add(sla.Value);
+
+        db.BudgetApprovals.Add(new BudgetApproval
+        {
+            BudgetId = entity.Id,
+            FromPhase = fromPhase,
+            ToPhase = request.TargetPhase,
+            ApproverUserId = currentUser.UserId,
+            Decision = request.Decision,
+            Comment = request.Comment,
+            ApprovedAt = DateTime.UtcNow,
+        });
+
+        string? actorName = null;
+        if (currentUser.UserId is Guid uid)
+        {
+            var u = await userManager.FindByIdAsync(uid.ToString());
+            actorName = u?.FullName ?? u?.Email;
+        }
+        db.BudgetChangelogs.Add(new BudgetChangelog
+        {
+            BudgetId = entity.Id,
+            EntityType = BudgetEntityType.Workflow,
+            Action = ChangelogAction.Transition,
+            PhaseAtChange = request.TargetPhase,
+            UserId = currentUser.UserId,
+            UserName = actorName ?? "Hệ thống",
+            Summary = $"Chuyển phase {fromPhase} → {request.TargetPhase}",
+            ContextNote = request.Comment,
+        });
+        await db.SaveChangesAsync(ct);
+    }
+}
+
+// ========== LIST ==========
+
+public record ListBudgetsQuery(
+    BudgetPhase? Phase = null,
+    Guid? ProjectId = null,
+    int? NamNganSach = null) : PagedRequest, IRequest<PagedResult<BudgetListItemDto>>;
+
+public class ListBudgetsQueryHandler(
+    IApplicationDbContext db) : IRequestHandler<ListBudgetsQuery, PagedResult<BudgetListItemDto>>
+{
+    public async Task<PagedResult<BudgetListItemDto>> Handle(ListBudgetsQuery request, CancellationToken ct)
+    {
+        var q = from e in db.Budgets.AsNoTracking()
+                join p in db.Projects.AsNoTracking() on e.ProjectId equals p.Id
+                select new { e, p };
+
+        if (request.Phase is not null) q = q.Where(x => x.e.Phase == request.Phase);
+        if (request.ProjectId is not null) q = q.Where(x => x.e.ProjectId == request.ProjectId);
+        if (request.NamNganSach is not null) q = q.Where(x => x.e.NamNganSach == request.NamNganSach);
+        if (!string.IsNullOrWhiteSpace(request.Search))
+        {
+            var s = request.Search.Trim();
+            q = q.Where(x => (x.e.MaNganSach != null && x.e.MaNganSach.Contains(s))
+                || x.e.TenNganSach.Contains(s) || x.p.Name.Contains(s));
+        }
+        q = request.SortDesc ? q.OrderByDescending(x => x.e.CreatedAt) : q.OrderBy(x => x.e.CreatedAt);
+
+        var total = await q.CountAsync(ct);
+        var items = await q.Skip((request.Page - 1) * request.PageSize).Take(request.PageSize)
+            .Select(x => new BudgetListItemDto(
+                x.e.Id, x.e.MaNganSach, x.e.TenNganSach, x.e.NamNganSach, x.e.Phase,
+                x.e.ProjectId, x.p.Name, x.e.TongNganSach, x.e.SlaDeadline, x.e.CreatedAt))
+            .ToListAsync(ct);
+        return new PagedResult<BudgetListItemDto>(items, total, request.Page, request.PageSize);
+    }
+}
+
+// ========== GET detail bundle ==========
+
+public record GetBudgetQuery(Guid Id) : IRequest<BudgetDetailBundleDto>;
+
+public class GetBudgetQueryHandler(
+    IApplicationDbContext db,
+    UserManager<User> userManager) : IRequestHandler<GetBudgetQuery, BudgetDetailBundleDto>
+{
+    public async Task<BudgetDetailBundleDto> Handle(GetBudgetQuery request, CancellationToken ct)
+    {
+        var e = await db.Budgets.AsNoTracking()
+            .Include(x => x.Details)
+            .Include(x => x.Approvals)
+            .FirstOrDefaultAsync(x => x.Id == request.Id, ct)
+            ?? throw new NotFoundException("Budget", request.Id);
+
+        var project = await db.Projects.AsNoTracking().FirstOrDefaultAsync(p => p.Id == e.ProjectId, ct);
+        var department = e.DepartmentId is null ? null : await db.Departments.AsNoTracking()
+            .FirstOrDefaultAsync(d => d.Id == e.DepartmentId, ct);
+
+        var userIds = new HashSet<Guid>();
+        if (e.DrafterUserId is Guid did) userIds.Add(did);
+        foreach (var a in e.Approvals) if (a.ApproverUserId is Guid aid) userIds.Add(aid);
+        var users = await userManager.Users.AsNoTracking()
+            .Where(u => userIds.Contains(u.Id))
+            .ToDictionaryAsync(u => u.Id, u => u.FullName, ct);
+
+        var policy = BudgetPolicies.Default;
+
+        return new BudgetDetailBundleDto(
+            e.Id, e.MaNganSach, e.TenNganSach, e.Description, e.NamNganSach, e.Phase,
+            e.ProjectId, project?.Name ?? "",
+            e.DepartmentId, department?.Name,
+            e.DrafterUserId, e.DrafterUserId is Guid d && users.TryGetValue(d, out var dn) ? dn : null,
+            e.TongNganSach, e.SlaDeadline, e.CreatedAt, e.UpdatedAt,
+            e.Details.OrderBy(d => d.Order).Select(d => new BudgetDetailDto(
+                d.Id, d.GroupCode, d.GroupName, d.ItemCode, d.NoiDung, d.DonViTinh,
+                d.KhoiLuong, d.DonGia, d.ThanhTien, d.Order, d.GhiChu)).ToList(),
+            e.Approvals.OrderBy(a => a.ApprovedAt).Select(a => new BudgetApprovalDto(
+                a.Id, a.FromPhase, a.ToPhase, a.ApproverUserId,
+                a.ApproverUserId is Guid uid && users.TryGetValue(uid, out var an) ? an : null,
+                a.Decision, a.Comment, a.ApprovedAt)).ToList(),
+            new BudgetWorkflowSummaryDto(
+                policy.Name, policy.Description,
+                policy.ActivePhases.ToList(),
+                policy.NextPhasesFrom(e.Phase).ToList()));
+    }
+}
+
+// ========== DELETE ==========
+
+public record DeleteBudgetCommand(Guid Id) : IRequest;
+
+public class DeleteBudgetCommandHandler(
+    IApplicationDbContext db) : IRequestHandler<DeleteBudgetCommand>
+{
+    public async Task Handle(DeleteBudgetCommand request, CancellationToken ct)
+    {
+        var entity = await db.Budgets.FirstOrDefaultAsync(x => x.Id == request.Id, ct)
+            ?? throw new NotFoundException("Budget", request.Id);
+        if (entity.Phase != BudgetPhase.DangSoanThao && entity.Phase != BudgetPhase.TuChoi)
+            throw new ConflictException("Chỉ xóa được ngân sách phase Soạn thảo / Từ chối.");
+        db.Budgets.Remove(entity);
+        await db.SaveChangesAsync(ct);
+    }
+}
+
+// ========== Detail CRUD ==========
+
+public record AddBudgetDetailCommand(
+    Guid BudgetId, string GroupCode, string GroupName, string? ItemCode, string NoiDung,
+    string? DonViTinh, decimal KhoiLuong, decimal DonGia, decimal ThanhTien, string? GhiChu) : IRequest<Guid>;
+
+public class AddBudgetDetailCommandHandler(
+    IApplicationDbContext db,
+    ICurrentUser currentUser) : IRequestHandler<AddBudgetDetailCommand, Guid>
+{
+    public async Task<Guid> Handle(AddBudgetDetailCommand request, CancellationToken ct)
+    {
+        var bg = await db.Budgets.FirstOrDefaultAsync(x => x.Id == request.BudgetId, ct)
+            ?? throw new NotFoundException("Budget", request.BudgetId);
+        var maxOrder = await db.BudgetDetails.Where(d => d.BudgetId == bg.Id)
+            .Select(d => (int?)d.Order).MaxAsync(ct);
+        var entity = new BudgetDetail
+        {
+            BudgetId = bg.Id,
+            GroupCode = request.GroupCode, GroupName = request.GroupName,
+            ItemCode = request.ItemCode, NoiDung = request.NoiDung, DonViTinh = request.DonViTinh,
+            KhoiLuong = request.KhoiLuong, DonGia = request.DonGia, ThanhTien = request.ThanhTien,
+            GhiChu = request.GhiChu, Order = (maxOrder ?? 0) + 1,
+        };
+        db.BudgetDetails.Add(entity);
+
+        // Recompute TongNganSach
+        bg.TongNganSach = await db.BudgetDetails.Where(d => d.BudgetId == bg.Id)
+            .SumAsync(d => d.ThanhTien, ct) + entity.ThanhTien;
+
+        db.BudgetChangelogs.Add(new BudgetChangelog
+        {
+            BudgetId = bg.Id, EntityType = BudgetEntityType.Detail, EntityId = entity.Id,
+            Action = ChangelogAction.Insert, PhaseAtChange = bg.Phase,
+            UserId = currentUser.UserId,
+            Summary = $"Thêm hạng mục {request.GroupCode} — {request.NoiDung}",
+        });
+        await db.SaveChangesAsync(ct);
+        return entity.Id;
+    }
+}
+
+public record UpdateBudgetDetailCommand(
+    Guid BudgetId, Guid DetailId, string GroupCode, string GroupName, string? ItemCode, string NoiDung,
+    string? DonViTinh, decimal KhoiLuong, decimal DonGia, decimal ThanhTien, string? GhiChu) : IRequest;
+
+public class UpdateBudgetDetailCommandHandler(
+    IApplicationDbContext db) : IRequestHandler<UpdateBudgetDetailCommand>
+{
+    public async Task Handle(UpdateBudgetDetailCommand request, CancellationToken ct)
+    {
+        var entity = await db.BudgetDetails
+            .FirstOrDefaultAsync(d => d.Id == request.DetailId && d.BudgetId == request.BudgetId, ct)
+            ?? throw new NotFoundException("BudgetDetail", request.DetailId);
+        entity.GroupCode = request.GroupCode; entity.GroupName = request.GroupName;
+        entity.ItemCode = request.ItemCode; entity.NoiDung = request.NoiDung; entity.DonViTinh = request.DonViTinh;
+        entity.KhoiLuong = request.KhoiLuong; entity.DonGia = request.DonGia; entity.ThanhTien = request.ThanhTien;
+        entity.GhiChu = request.GhiChu;
+
+        var bg = await db.Budgets.FirstOrDefaultAsync(b => b.Id == request.BudgetId, ct);
+        if (bg != null)
+            bg.TongNganSach = await db.BudgetDetails.Where(d => d.BudgetId == bg.Id)
+                .SumAsync(d => d.ThanhTien, ct);
+
+        await db.SaveChangesAsync(ct);
+    }
+}
+
+public record DeleteBudgetDetailCommand(Guid BudgetId, Guid DetailId) : IRequest;
+
+public class DeleteBudgetDetailCommandHandler(
+    IApplicationDbContext db) : IRequestHandler<DeleteBudgetDetailCommand>
+{
+    public async Task Handle(DeleteBudgetDetailCommand request, CancellationToken ct)
+    {
+        var entity = await db.BudgetDetails
+            .FirstOrDefaultAsync(d => d.Id == request.DetailId && d.BudgetId == request.BudgetId, ct)
+            ?? throw new NotFoundException("BudgetDetail", request.DetailId);
+        db.BudgetDetails.Remove(entity);
+
+        var bg = await db.Budgets.FirstOrDefaultAsync(b => b.Id == request.BudgetId, ct);
+        if (bg != null)
+            bg.TongNganSach = await db.BudgetDetails.Where(d => d.BudgetId == bg.Id && d.Id != entity.Id)
+                .SumAsync(d => d.ThanhTien, ct);
+
+        await db.SaveChangesAsync(ct);
+    }
+}
+
+// ========== CHANGELOG list ==========
+
+public record ListBudgetChangelogsQuery(Guid BudgetId, int Take = 200) : IRequest<List<BudgetChangelogDto>>;
+
+public class ListBudgetChangelogsQueryHandler(IApplicationDbContext db)
+    : IRequestHandler<ListBudgetChangelogsQuery, List<BudgetChangelogDto>>
+{
+    public async Task<List<BudgetChangelogDto>> Handle(ListBudgetChangelogsQuery request, CancellationToken ct) =>
+        await db.BudgetChangelogs.AsNoTracking()
+            .Where(c => c.BudgetId == request.BudgetId)
+            .OrderByDescending(c => c.CreatedAt)
+            .Take(request.Take)
+            .Select(c => new BudgetChangelogDto(
+                c.Id, c.EntityType, c.EntityId, c.Action, c.PhaseAtChange,
+                c.UserId, c.UserName, c.Summary, c.FieldChangesJson, c.ContextNote, c.CreatedAt))
+            .ToListAsync(ct);
+}

src/Backend/SolutionErp.Application/Budgets/Dtos/BudgetDtos.cs

@@ -0,0 +1,79 @@
+using SolutionErp.Domain.Budgets;
+using SolutionErp.Domain.Contracts;
+
+namespace SolutionErp.Application.Budgets.Dtos;
+
+public record BudgetListItemDto(
+    Guid Id,
+    string? MaNganSach,
+    string TenNganSach,
+    int NamNganSach,
+    BudgetPhase Phase,
+    Guid ProjectId,
+    string ProjectName,
+    decimal TongNganSach,
+    DateTime? SlaDeadline,
+    DateTime CreatedAt);
+
+public record BudgetDetailDto(
+    Guid Id,
+    string GroupCode,
+    string GroupName,
+    string? ItemCode,
+    string NoiDung,
+    string? DonViTinh,
+    decimal KhoiLuong,
+    decimal DonGia,
+    decimal ThanhTien,
+    int Order,
+    string? GhiChu);
+
+public record BudgetApprovalDto(
+    Guid Id,
+    BudgetPhase FromPhase,
+    BudgetPhase ToPhase,
+    Guid? ApproverUserId,
+    string? ApproverName,
+    ApprovalDecision Decision,
+    string? Comment,
+    DateTime ApprovedAt);
+
+public record BudgetChangelogDto(
+    Guid Id,
+    BudgetEntityType EntityType,
+    Guid? EntityId,
+    ChangelogAction Action,
+    BudgetPhase? PhaseAtChange,
+    Guid? UserId,
+    string? UserName,
+    string? Summary,
+    string? FieldChangesJson,
+    string? ContextNote,
+    DateTime CreatedAt);
+
+public record BudgetWorkflowSummaryDto(
+    string PolicyName,
+    string PolicyDescription,
+    List<BudgetPhase> ActivePhases,
+    List<BudgetPhase> NextPhases);
+
+public record BudgetDetailBundleDto(
+    Guid Id,
+    string? MaNganSach,
+    string TenNganSach,
+    string? Description,
+    int NamNganSach,
+    BudgetPhase Phase,
+    Guid ProjectId,
+    string ProjectName,
+    Guid? DepartmentId,
+    string? DepartmentName,
+    Guid? DrafterUserId,
+    string? DrafterName,
+    decimal TongNganSach,
+    DateTime? SlaDeadline,
+    DateTime CreatedAt,
+    DateTime? UpdatedAt,
+    List<BudgetDetailDto> Details,
+    List<BudgetApprovalDto> Approvals,
+    BudgetWorkflowSummaryDto Workflow);

src/Backend/SolutionErp.Application/Common/Interfaces/IApplicationDbContext.cs

@@ -1,4 +1,5 @@
 using Microsoft.EntityFrameworkCore;
+using SolutionErp.Domain.Budgets;
 using SolutionErp.Domain.Contracts;
 using SolutionErp.Domain.Contracts.Details;
 using SolutionErp.Domain.Forms;
@@ -58,5 +59,11 @@ public interface IApplicationDbContext
     DbSet<PurchaseEvaluationWorkflowStepApprover> PurchaseEvaluationWorkflowStepApprovers { get; }
     DbSet<PurchaseEvaluationCodeSequence> PurchaseEvaluationCodeSequences { get; }
 
+    // Module Ngân sách (Phase 7)
+    DbSet<Budget> Budgets { get; }
+    DbSet<BudgetDetail> BudgetDetails { get; }
+    DbSet<BudgetApproval> BudgetApprovals { get; }
+    DbSet<BudgetChangelog> BudgetChangelogs { get; }
+
     Task<int> SaveChangesAsync(CancellationToken cancellationToken = default);
 }