Add clanker code

dealer/Owner.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace dealer
+{
+    public class Owner
+    {
+        public Guid Id { get; set; } = Guid.NewGuid();
+        public string? Jmeno { get; set; }
+        public string? Prijmeni { get; set; }
+        public string? Adresa { get; set; }
+        public string? Telefon { get; set; }
+        public string? Email { get; set; }
+
+        public string CeleJmeno => $"{Jmeno} {Prijmeni}".Trim();
+        
+        public string DisplayText => string.IsNullOrEmpty(CeleJmeno) 
+            ? Email ?? Telefon ?? "Neznamy vlastnik" 
+            : CeleJmeno;
+
+        public override string ToString() => DisplayText;
+    }
+}