feat: add application preloader, identity roles, and resilient database initialization with automated seeding

scratch/check_db.cs

@@ -0,0 +1,44 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.EntityFrameworkCore;
+using NexusReader.Infrastructure.Persistence;
+using Microsoft.Extensions.Configuration;
+using NexusReader.Domain.Entities;
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+
+var configuration = new ConfigurationBuilder()
+    .AddJsonFile("src/NexusReader.Web.New/appsettings.json")
+    .Build();
+
+var services = new ServiceCollection();
+var pgConnectionString = configuration.GetConnectionString("PostgresConnection");
+if (!string.IsNullOrEmpty(pgConnectionString))
+{
+    services.AddDbContext<AppDbContext>(options => options.UseNpgsql(pgConnectionString));
+}
+else
+{
+    services.AddDbContext<AppDbContext>(options => options.UseSqlite(configuration.GetConnectionString("SqliteConnection")));
+}
+
+var serviceProvider = services.BuildServiceProvider();
+using var scope = serviceProvider.CreateScope();
+var dbContext = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+
+try 
+{
+    var user = await dbContext.Users.FirstOrDefaultAsync(u => u.Email == "admin@nexus.com");
+    if (user == null)
+    {
+        Console.WriteLine("User admin@nexus.com NOT FOUND in database.");
+    }
+    else
+    {
+        Console.WriteLine($"User found: {user.Email}, Id: {user.Id}, EmailConfirmed: {user.EmailConfirmed}");
+    }
+}
+catch (Exception ex)
+{
+    Console.WriteLine($"Error accessing database: {ex.Message}");
+}