Colocated entity type configurations with entities

Added tenant entities and models
Modified db context

PostFundManagement.Domain/Entities/Contract.cs

@@ -1,9 +1,43 @@
 namespace PostFundManagement.Domain.Entities;
 
-[EntityTypeConfiguration<Configuration.Entities.Contract, Contract>]
+[EntityTypeConfiguration<ContractConfiguration, Contract>]
 public class Contract : Models.Contract
 {
     public virtual Award? Award { get; set; }
 
     public virtual User? Creator { get; set; }
+}
+
+public sealed class ContractConfiguration : IEntityTypeConfiguration<Contract>
+{
+    public void Configure(EntityTypeBuilder<Contract> builder)
+    {
+        builder.ToTable(nameof(Contract).Pluralize());
+
+        builder.HasKey(pk => pk.Id);
+        builder.HasIndex(f => f.AwardId).IsUnique();
+
+        builder.Property(f => f.AwardId).IsRequired();
+        builder.Property(f => f.CreatedBy).IsRequired();
+        builder.Property(f => f.CreatedAt).IsRequired().HasDefaultValueSql("now()");
+        builder.Property(f => f.ExternalSignatureId).IsRequired(false);
+        builder.Property(f => f.SignedDocumentUrl).IsRequired(false);
+        builder.Property(f => f.EffectiveAt).IsRequired(false);
+        builder.Property(f => f.ExpiresAt).IsRequired(false);
+        builder.Property(f => f.TotalValue).IsRequired().HasPrecision(18, 2);
+        builder.Property(f => f.Status).IsRequired().HasConversion<int>().HasDefaultValueSql("1")
+            .HasSentinel(ContractStatus.Draft);
+
+        builder.HasOne(f => f.Award)
+            .WithOne(f => f.Contract)
+            .HasForeignKey<Domain.Entities.Contract>(fk => fk.AwardId)
+            .IsRequired()
+            .OnDelete(DeleteBehavior.Restrict);
+
+        builder.HasOne(f => f.Creator)
+            .WithMany()
+            .HasForeignKey(fk => fk.CreatedBy)
+            .IsRequired()
+            .OnDelete(DeleteBehavior.NoAction);
+    }
 }