Разбить Infrastructure и корень Deal.Api по назначению

Integrations -> Abstractions/Exceptions/Extensions/Models/Options/
Services (включая Storage); Persistence-конфигурации -> Configurations;
корень Deal.Api (оркестратор/планировщики/DTO) -> Services/Dtos.
namespace приведён к путям, using добавлены/дедуплицированы, FQN
обновлены.

src/core/Deal.Infrastructure/Persistence/Configurations/SessionConfiguration.cs

@@ -0,0 +1,36 @@
+using Deal.Infrastructure.Persistence.Entities;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+using Deal.Infrastructure.Persistence;
+using Deal.Infrastructure.Persistence.Configurations;
+
+namespace Deal.Infrastructure.Persistence.Configurations;
+
+/// <summary>
+/// EF-конфигурация сессии: таблица sessions в схеме public.
+/// </summary>
+public sealed class SessionConfiguration : IEntityTypeConfiguration<SessionEntity>
+{
+    private const int TokenHashMaxLength = 64;
+    private const int LoginMaxLength = 200;
+
+    public void Configure(EntityTypeBuilder<SessionEntity> builder)
+    {
+        builder.ToTable("sessions", "public");
+
+        builder.HasKey(x => x.TokenHash);
+
+        builder.Property(x => x.TokenHash).HasMaxLength(TokenHashMaxLength);
+        builder.Property(x => x.Login).HasMaxLength(LoginMaxLength).IsRequired();
+        builder.Property(x => x.ExpiresAt).IsRequired();
+        builder.Property(x => x.CreatedAt).IsRequired();
+
+        builder.HasIndex(x => x.UserId);
+        builder.HasIndex(x => x.ExpiresAt);
+
+        builder.HasOne<UserEntity>()
+            .WithMany()
+            .HasForeignKey(x => x.UserId)
+            .OnDelete(DeleteBehavior.Cascade);
+    }
+}