fix: HIGH+MEDIUM bugs from full audit - listen error, JWT, upload, mailer, webhook

backend/mailer.js

@@ -42,17 +42,28 @@ function renderTemplate(template, vars) {
   return { subject, body };
 }
 
+let _transporter = null;
+let _transporterKey = '';
+
+function getTransporter(cfg) {
+  const key = `${cfg.host}:${cfg.port}:${cfg.user}`;
+  if (_transporter && _transporterKey === key) return _transporter;
+  _transporterKey = key;
+  _transporter = nodemailer.createTransport({ host: cfg.host, port: cfg.port, secure: cfg.secure, auth: { user: cfg.user, pass: cfg.pass } });
+  return _transporter;
+}
+
 async function sendEmail(to, templateCode, vars) {
   try {
     const cfg = await getSmtpConfig();
     if (!cfg.host || !cfg.user) { console.log('[Mailer] SMTP未配置'); return false; }
     const template = await getTemplate(templateCode);
     if (!template) { console.log('[Mailer] 模板不存在:', templateCode); return false; }
-    const allVars = { ...vars, site_name: await getSiteName(), site_url: await getSiteUrl() };
+    const siteName = await getSiteName();
+    const allVars = { ...vars, site_name: siteName, site_url: await getSiteUrl() };
     const { subject, body } = renderTemplate(template, allVars);
-
-    const transporter = nodemailer.createTransport({ host: cfg.host, port: cfg.port, secure: cfg.secure, auth: { user: cfg.user, pass: cfg.pass } });
-    await transporter.sendMail({ from: `"${await getSiteName()}" <${cfg.from}>`, to, subject, html: body });
+    const transporter = getTransporter(cfg);
+    await transporter.sendMail({ from: `"${siteName}" <${cfg.from}>`, to, subject, html: body });
     return true;
   } catch (err) { console.error('[Mailer]', err.message); return false; }
 }