zabezpieczenie przed otwarciem paragonow z niestniejacej listy w panelu admina

app.py

@@ -2856,6 +2856,11 @@ def admin_receipts(list_id=None):
         page, per_page = get_page_args(default_per_page=24, max_per_page=200)
 
         if list_id is not None:
+            target_list = db.session.get(ShoppingList, list_id)
+            if not target_list:
+                flash("Lista nie istnieje.", "danger")
+                return redirect(url_for("admin_lists_access"))
+
             all_receipts = (
                 Receipt.query.options(joinedload(Receipt.uploaded_by_user))
                 .filter_by(list_id=list_id)