fix: POS items added to cart despite low qty (#29126)

diff --git a/erpnext/selling/page/point_of_sale/pos_controller.js b/erpnext/selling/page/point_of_sale/pos_controller.js
index e61a634..ce74f6d 100644
--- a/erpnext/selling/page/point_of_sale/pos_controller.js
+++ b/erpnext/selling/page/point_of_sale/pos_controller.js
@@ -643,7 +643,7 @@
 				message: __('Item Code: {0} is not available under warehouse {1}.', [bold_item_code, bold_warehouse])
 			})
 		} else if (available_qty < qty_needed) {
-			frappe.show_alert({
+			frappe.throw({
 				message: __('Stock quantity not enough for Item Code: {0} under warehouse {1}. Available quantity {2}.', [bold_item_code, bold_warehouse, bold_available_qty]),
 				indicator: 'orange'
 			});