feat: add more detailed history and group per day

lib/models/tab_item.dart

@@ -1,3 +1,6 @@
+import 'tab_item_purchase.dart';
+import '../utils/collection_utils.dart';
+
 class TabItem {
   final String id;
   final String tabId;
@@ -5,6 +8,7 @@ class TabItem {
   final String productName;
   final int quantity;
   final int unitPriceInCents;
+  final List<TabItemPurchase> purchases;
 
   const TabItem({
     required this.id,
@@ -13,6 +17,7 @@ class TabItem {
     required this.productName,
     required this.quantity,
     required this.unitPriceInCents,
+    this.purchases = const [],
   });
 
   int get lineTotalInCents => quantity * unitPriceInCents;
@@ -34,15 +39,17 @@ class TabItem {
           productId == other.productId &&
           productName == other.productName &&
           quantity == other.quantity &&
-          unitPriceInCents == other.unitPriceInCents;
+          unitPriceInCents == other.unitPriceInCents &&
+          listEquals(purchases, other.purchases);
 
   @override
   int get hashCode => Object.hash(
-        id,
-        tabId,
-        productId,
-        productName,
-        quantity,
-        unitPriceInCents,
-      );
+    id,
+    tabId,
+    productId,
+    productName,
+    quantity,
+    unitPriceInCents,
+    Object.hashAll(purchases),
+  );
 }