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

src/NexusReader.Web.New/Program.cs

@@ -81,6 +81,7 @@ builder.Services.AddAuthentication(options =>
     });
 
 builder.Services.AddIdentityApiEndpoints<NexusUser>()
+    .AddRoles<IdentityRole>()
     .AddEntityFrameworkStores<AppDbContext>();
 
 builder.Services.ConfigureApplicationCookie(options =>
@@ -113,11 +114,38 @@ builder.Services.Configure<IdentityOptions>(options =>
 
 var app = builder.Build();
 
-// Ensure Database is initialized
+// Ensure Database is initialized and seeded
 using (var scope = app.Services.CreateScope())
 {
-    var dbContext = scope.ServiceProvider.GetRequiredService<NexusReader.Infrastructure.Persistence.AppDbContext>();
-    await dbContext.Database.MigrateAsync();
+    var services = scope.ServiceProvider;
+    var logger = services.GetRequiredService<ILogger<Program>>();
+    var dbContext = services.GetRequiredService<NexusReader.Infrastructure.Persistence.AppDbContext>();
+    
+    int maxRetries = 5;
+    int delayMs = 2000;
+    
+    for (int i = 0; i < maxRetries; i++)
+    {
+        try
+        {
+            logger.LogInformation("Próba połączenia z bazą danych (próba {Attempt}/{MaxRetries})...", i + 1, maxRetries);
+            await dbContext.Database.MigrateAsync();
+            await DbInitializer.SeedAsync(services);
+            logger.LogInformation("Baza danych zainicjowana pomyślnie.");
+            break;
+        }
+        catch (Npgsql.NpgsqlException ex) when (i < maxRetries - 1)
+        {
+            logger.LogWarning("Błąd połączenia z bazą danych: {Message}. Ponowna próba za {Delay}ms...", ex.Message, delayMs);
+            await Task.Delay(delayMs);
+            delayMs *= 2; // Exponential backoff
+        }
+        catch (Exception ex)
+        {
+            logger.LogCritical(ex, "Krytyczny błąd podczas inicjalizacji bazy danych.");
+            throw;
+        }
+    }
 }
 
 // Configure the HTTP request pipeline.