Lots of data and model setup

SVSim.Database/Models/BattlefieldEntry.cs

@@ -0,0 +1,9 @@
+using DCGEngine.Database.Models;
+
+namespace SVSim.Database.Models;
+
+public class BattlefieldEntry : BaseEntity<int>
+{
+    public string Name { get; set; } = string.Empty;
+    public bool IsOpen { get; set; }
+}