fix:manage edit for extra bezoekers payments

packages/api/src/email.ts

@@ -1,11 +1,18 @@
 import { env } from "@kk/env/server";
 import nodemailer from "nodemailer";
 
-function createTransport() {
+// Singleton transport — created once per module, reused across all email sends.
+// Re-creating it on every call causes EventEmitter listener accumulation in
+// long-lived Cloudflare Worker processes, triggering memory leak warnings.
+let _transport: nodemailer.Transporter | null | undefined;
+
+function getTransport(): nodemailer.Transporter | null {
+	if (_transport !== undefined) return _transport;
 	if (!env.SMTP_HOST || !env.SMTP_USER || !env.SMTP_PASS) {
+		_transport = null;
 		return null;
 	}
-	return nodemailer.createTransport({
+	_transport = nodemailer.createTransport({
 		host: env.SMTP_HOST,
 		port: env.SMTP_PORT,
 		secure: env.SMTP_PORT === 465,
@@ -14,6 +21,7 @@ function createTransport() {
 			pass: env.SMTP_PASS,
 		},
 	});
+	return _transport;
 }
 
 const from = env.SMTP_FROM ?? "Kunstenkamp <info@kunstenkamp.be>";
@@ -223,7 +231,7 @@ export async function sendConfirmationEmail(params: {
 	wantsToPerform: boolean;
 	artForm?: string | null;
 }) {
-	const transport = createTransport();
+	const transport = getTransport();
 	if (!transport) {
 		console.warn("SMTP not configured — skipping confirmation email");
 		return;
@@ -249,7 +257,7 @@ export async function sendUpdateEmail(params: {
 	wantsToPerform: boolean;
 	artForm?: string | null;
 }) {
-	const transport = createTransport();
+	const transport = getTransport();
 	if (!transport) {
 		console.warn("SMTP not configured — skipping update email");
 		return;
@@ -272,7 +280,7 @@ export async function sendCancellationEmail(params: {
 	to: string;
 	firstName: string;
 }) {
-	const transport = createTransport();
+	const transport = getTransport();
 	if (!transport) {
 		console.warn("SMTP not configured — skipping cancellation email");
 		return;