update: add test bar chart data

app/lib/widgets/bar_data.dart

+import 'dart:math';
 import 'package:flutter/material.dart';
 import 'package:fl_chart/fl_chart.dart';
 
@@ -28,12 +29,24 @@ class _BarDataState extends State<BarData> {
     for (int i = 0; i < 7; i++) {
       var entry = selectedSubDiv?.iceStats[i];
       if (entry != null) {
+        // NB test data for demo
+        Random random = Random();
+        double blackIce = 2.0 + random.nextDouble() * (4.0 - 2.0);
+        double slushIce = 1.0 + random.nextDouble() * (1.5 - 1.0);
+        double snowDepth = random.nextDouble() * 1.3;
+
         barData[i] = [
-          entry.blackIce,
-          entry.slushIce,
-          entry.snowDepth,
+          //entry.blackIce,
+          //entry.slushIce,
+          //entry.snowDepth,
+          blackIce,  // NB test data for demo
+          slushIce,  // ...
+          snowDepth, // ..
         ];
 
+        // NB test data for demo
+        totalHeight = blackIce + slushIce + snowDepth + 0.3; // NB demo data
+
         // Find tallest layer
         if (entry.totalIce > totalHeight) {
           totalHeight = entry.totalIce;