fix(qris): kode unik lintas order + pelunasan multi-tagihan; fix kirim tagihan manual

- webhook QRIS: nominal total tagihan + kode -> lunaskan semua tagihan pelanggan
- isQrisAmountTaken() cek invoice+voucher+donasi (cegah ambigu)
- billingSendService: require('qrcode'), nominal unik + {{qris_kode}}, fallback link
- pilih tagihan terlama; pesan pengingat manual yang jujur saat di-skip
- versi 0.5.5

app-customer.js

@@ -1011,7 +1011,21 @@ app.post('/api/webhook/v1/payment-notif', multer().any(), async (req, res) => {
           const custId = Number(inv.customer_id || 0);
           if (invId > 0) {
             const noteLine = `AUTO-QRIS: cocok nominal unik Rp ${amount} (service=${String(service || '-')}, notif=${notifId || '-'})`;
-            markInvoicePaidAppendNote.run('QRIS', noteLine, noteLine, notifId || null, invId);
+            // QRIS multi-tagihan: nominal = total semua tagihan + kode unik yang disimpan
+            // di salah satu invoice. Lunaskan semuanya, jangan hanya invoice pemilik kode.
+            const unpaidRows = custId > 0
+              ? db.prepare("SELECT id, amount FROM invoices WHERE customer_id=? AND status='unpaid' ORDER BY period_year ASC, period_month ASC, id ASC").all(custId)
+              : [];
+            const totalUnpaid = unpaidRows.reduce((sum, row) => sum + (Number(row.amount) || 0), 0);
+            const qrisCode = Number(inv.qris_unique_code || 0) || 0;
+            if (qrisCode > 0 && unpaidRows.length > 1 && totalUnpaid + qrisCode === Number(amount)) {
+              const noteBundle = `${noteLine} — lunas ${unpaidRows.length} tagihan`;
+              const payOne = db.prepare(`UPDATE invoices SET status='paid', paid_at=NOW_LOCAL(), paid_by_name=?, notes=CASE WHEN notes IS NULL OR TRIM(notes) = '' THEN ? ELSE notes || '\n' || ? END, qris_paid_notif_id=? WHERE id=? AND status='unpaid'`);
+              for (const row of unpaidRows) payOne.run('QRIS', noteBundle, noteBundle, notifId || null, row.id);
+              logger.info(`[WEBHOOK][payment-notif] MATCH bundle invoice=${invId} invoices=${unpaidRows.length} total=${totalUnpaid} amount=${amount}`);
+            } else {
+              markInvoicePaidAppendNote.run('QRIS', noteLine, noteLine, notifId || null, invId);
+            }
             matchedInvoiceId = invId;
 
             if (notifId) {