fix(qr-custom): center QR, timer berhenti, refund saat lunas, regenerate expired

- link publik: QR center, nominal/QR/timer disembunyikan saat expired
- reject/refund untuk paid
- regenerate QR expired (kode unik baru) di detail & tabel
- versi 0.6.4

package.json

@@ -1,6 +1,6 @@
 {
   "name": "open-isp",
-  "version": "0.6.3",
+  "version": "0.6.4",
   "description": "OPEN-ISP \u2014 sistem billing & manajemen ISP open-source (PWA pelanggan, multi-OLT, RADIUS, WhatsApp, QRIS)",
   "main": "app-customer.js",
   "scripts": {