Refactor inventory chart data representation; change dataset type from bar to pie and update corresponding keys for improved visualization

routes.py

@@ -170,12 +170,12 @@ def index():
     # Convert pandas/numpy int64s to plain old Python ints
     pivot = pivot.astype(int)
     labels = list(pivot.index)
-    data = [int(x) for x in pivot.values]  # <- This is what fixes the JSON error
+    data = [int(x) for x in pivot.values]  
 
     datasets = [{
-        'type': 'bar',
-        'x': labels,
-        'y': data,
+        'type': 'pie',
+        'labels': labels,
+        'values': data,
         'name': 'Inventory Conditions'
     }]