reworked app startup

Stars Assistant/Model/Planet.cs

@@ -14,7 +14,7 @@ public class Planet
 
     public string? OwnerId { get; set; }
     
-    public string? StarbaseType { get; set; }
+    public string StarbaseType { get; set; } = String.Empty;
     
     public int ReportAge { get; set; } = 0;