<ul><li>OpenAIManager: Fixed $balance_color uninitialized before loop — PHP notice; added default value</li><li>OpenAIManager: Fixed $paid, $amount_due, $total_tokens undefined when $payer==0 — initialized to zero before conditional blocks</li><li>QRManager: Replaced 8 empty error:function(){} AJAX handlers with swal error messages — failures were silently dropped</li><li>QRManager: Replaced native alert() in download handler with swal warning</li></ul>