[CLAUDE] Phase1: foundation - BE Clean Arch + Identity + JWT + 2 FE React + login E2E

Backend (.NET 10):
- Domain: BaseEntity/AuditableEntity, ContractType/Phase/ApprovalDecision enums, User/Role (Identity<Guid>), AppRoles (12 const)
- Application: IApplicationDbContext/ICurrentUser/IDateTime/IJwtTokenService, custom exceptions, ValidationBehavior (MediatR pipeline), Auth CQRS (Login/Refresh/Me), DependencyInjection
- Infrastructure: ApplicationDbContext (IdentityDbContext), AuditingInterceptor (auto audit + soft delete), DbInitializer (seed 12 role + admin), DesignTimeDbContextFactory, JwtTokenService, DateTimeService, DI
- Api: CurrentUserService, GlobalExceptionMiddleware (ProblemDetails), AuthController, Program.cs rewrite (Serilog + JWT + CORS + Swagger), appsettings + launchSettings (port 5443)
- Migration Init applied to SolutionErp_Dev LocalDB

Frontend (React 19 + Vite 8 + Tailwind 4):
- fe-admin (:8082 blue) + fe-user (:8080 emerald) - shared structure, khac menu + brand color
- Tailwind 4 via @tailwindcss/vite plugin, theme brand colors
- AuthContext (localStorage token), ProtectedRoute, Layout (sidebar + header)
- UI kit: Button/Input/Label (CVA + Tailwind)
- LoginPage voi toast error, DashboardPage/InboxPage placeholder
- Axios interceptor: auto Bearer + 401 redirect
- TanStack Query client, React Router 7, Sonner toast

Package downgrades (do .NET 10 / TS 6 compat):
- MediatR 14 -> 12.4.1 (v14 breaking changes)
- Swashbuckle 10 -> 6.9.0 (v10 khong tuong thich OpenApi 2)
- Removed Microsoft.AspNetCore.OpenApi (conflict voi Swashbuckle)

E2E verified: POST /api/auth/login qua Vite proxy ca 2 FE -> JWT + user info

Credentials seed: admin@solutionerp.local / Admin@123456

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Backend/SolutionErp.Infrastructure/Persistence/Interceptors/AuditingInterceptor.cs

@@ -0,0 +1,65 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.ChangeTracking;
+using Microsoft.EntityFrameworkCore.Diagnostics;
+using SolutionErp.Application.Common.Interfaces;
+using SolutionErp.Domain.Common;
+
+namespace SolutionErp.Infrastructure.Persistence.Interceptors;
+
+public class AuditingInterceptor : SaveChangesInterceptor
+{
+    private readonly ICurrentUser _currentUser;
+    private readonly IDateTime _dateTime;
+
+    public AuditingInterceptor(ICurrentUser currentUser, IDateTime dateTime)
+    {
+        _currentUser = currentUser;
+        _dateTime = dateTime;
+    }
+
+    public override InterceptionResult<int> SavingChanges(DbContextEventData eventData, InterceptionResult<int> result)
+    {
+        Apply(eventData.Context);
+        return base.SavingChanges(eventData, result);
+    }
+
+    public override ValueTask<InterceptionResult<int>> SavingChangesAsync(
+        DbContextEventData eventData, InterceptionResult<int> result, CancellationToken cancellationToken = default)
+    {
+        Apply(eventData.Context);
+        return base.SavingChangesAsync(eventData, result, cancellationToken);
+    }
+
+    private void Apply(DbContext? context)
+    {
+        if (context is null) return;
+        var userId = _currentUser.UserId;
+        var now = _dateTime.UtcNow;
+
+        foreach (var entry in context.ChangeTracker.Entries<BaseEntity>())
+        {
+            switch (entry.State)
+            {
+                case EntityState.Added:
+                    entry.Entity.CreatedAt = now;
+                    entry.Entity.CreatedBy = userId;
+                    break;
+                case EntityState.Modified:
+                    entry.Entity.UpdatedAt = now;
+                    entry.Entity.UpdatedBy = userId;
+                    break;
+            }
+        }
+
+        foreach (var entry in context.ChangeTracker.Entries<AuditableEntity>())
+        {
+            if (entry.State == EntityState.Deleted)
+            {
+                entry.State = EntityState.Modified;
+                entry.Entity.IsDeleted = true;
+                entry.Entity.DeletedAt = now;
+                entry.Entity.DeletedBy = userId;
+            }
+        }
+    }
+}