Add one-to-one relationship between RecAction and OutRes

Introduced a new `OutRes` navigation property in the `RecAction`
class to establish a one-to-one relationship with the `OutRes`
entity. Updated `RecDbContext` to configure this relationship
using the Fluent API. The `OutRes` entity references its
associated `RecAction` via the `Action` navigation property,
with `ActionId` as the foreign key.

src/ReC.Domain/Entities/RecAction.cs

@@ -69,4 +69,6 @@ public class RecAction
 
     [Column("CHANGED_WHEN")]
     public DateTime? ChangedWhen { get; set; }
+
+    public OutRes? OutRes { get; set; }
 }

src/ReC.Infrastructure/RecDbContext.cs

@@ -35,5 +35,10 @@ public class RecDbContext(DbContextOptions<RecDbContext> options) : DbContext(op
         modelBuilder.Entity<HeaderQueryResult>().HasNoKey();
 
         modelBuilder.Entity<BodyQueryResult>().HasNoKey();
+
+        modelBuilder.Entity<RecAction>()
+            .HasOne(act => act.OutRes)
+            .WithOne(res => res.Action)
+            .HasForeignKey<OutRes>(res => res.ActionId);
     }
 }