feat: New Open Tab dialog with search and optional customer email. Drinks are now grouped per order. Payments trigger cha-ching and money rain.

lib/models/tab_item_purchase.dart

@@ -4,11 +4,15 @@ class TabItemPurchase {
   final DateTime purchasedAt;
   final DateTime? removedAt;
 
+  /// The order it was rung up in; null for drinks from before orders.
+  final String? orderId;
+
   const TabItemPurchase({
     required this.id,
     required this.tabItemId,
     required this.purchasedAt,
     this.removedAt,
+    this.orderId,
   });
 
   bool get isRemoved => removedAt != null;
@@ -20,8 +24,10 @@ class TabItemPurchase {
           id == other.id &&
           tabItemId == other.tabItemId &&
           purchasedAt == other.purchasedAt &&
-          removedAt == other.removedAt;
+          removedAt == other.removedAt &&
+          orderId == other.orderId;
 
   @override
-  int get hashCode => Object.hash(id, tabItemId, purchasedAt, removedAt);
+  int get hashCode =>
+      Object.hash(id, tabItemId, purchasedAt, removedAt, orderId);
 }