feat(import): resolve color variety ID mappings mismatch, support unnamed parents in virtual litters, and implement SaleContract updates

GerbilManagerWebAPI/Migrations/20260613120908_AddContractAnimalPhoto.cs

@@ -0,0 +1,29 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace GerbilManagerWebAPI.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddContractAnimalPhoto : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<Guid>(
+                name: "PhotoId",
+                table: "SaleContractAnimal",
+                type: "uuid",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "PhotoId",
+                table: "SaleContractAnimal");
+        }
+    }
+}