Flush log on exit

src/GuiApp/Avalonia/FileTime.GuiApp.App/Program.cs

@@ -127,11 +127,15 @@ public static class Program
         => HandleUnhandledException(sender, e.Exception);
 
     private static void HandleUnhandledException(object? sender, Exception? ex, [CallerMemberName] string caller = "")
-        => Log.Fatal(
+    {
+        Log.Fatal(
             ex,
             "An unhandled exception come from '{Caller}' exception handler from an object of type '{Type}' and value '{Value}': {Exception}",
             caller,
             sender?.GetType().ToString() ?? "null",
             sender?.ToString() ?? "null",
             ex);
+        
+        Log.CloseAndFlush();
+    }
 }