flesh out the data scan UI, tweak selection table

Program.cs

@@ -4,6 +4,7 @@ using Avalonia;
 using System;
 
 using MercuryConverter.UI;
+using Avalonia.Logging;
 
 class Program
 {
@@ -13,7 +14,18 @@ class Program
     [STAThread]
     public static void Main(string[] args)
     {
-        BuildAvaloniaApp().StartWithClassicDesktopLifetime(args);
+        // BuildAvaloniaApp().StartWithClassicDesktopLifetime(args);
+        try
+        {
+            // prepare and run your App here
+            BuildAvaloniaApp()
+                .StartWithClassicDesktopLifetime(args);
+        }
+        catch (Exception e)
+        {
+            // here we can work with the exception, for example add it to our log file
+            Console.WriteLine($"App exception!!\b{e}");
+        }
     }
 
     // Avalonia configuration, don't remove; also used by visual designer.
@@ -21,5 +33,5 @@ class Program
         => AppBuilder.Configure<App>()
             .UsePlatformDetect()
             .WithInterFont()
-            .LogToTrace();
+            .LogToTrace(LogEventLevel.Debug);
 }