fix: add missing mail.js and dependencies to backend

backend/mail.js

@@ -0,0 +1,46 @@
+const nodemailer = require('nodemailer');
+require('dotenv').config();
+
+const transporter = nodemailer.createTransport({
+  host: process.env.SMTP_HOST || 'smtp.office365.com',
+  port: parseInt(process.env.SMTP_PORT || '587', 10),
+  secure: process.env.SMTP_SECURE === 'true', // true for 465, false for other ports (587 uses STARTTLS)
+  auth: {
+    user: process.env.SMTP_USER,
+    pass: process.env.SMTP_PASS,
+  },
+  tls: {
+    ciphers: 'SSLv3', // sometimes required for Office365
+    rejectUnauthorized: false
+  }
+});
+
+/**
+ * Sends an email using the configured SMTP server.
+ * @param {string} to - Recipient email address
+ * @param {string} subject - Email subject
+ * @param {string} text - Plain text body
+ * @param {string} html - HTML body (optional)
+ * @returns {Promise<any>} Info object from nodemailer
+ */
+const sendMail = async (to, subject, text, html = '') => {
+  try {
+    const info = await transporter.sendMail({
+      from: process.env.SMTP_FROM,
+      to,
+      subject,
+      text,
+      html
+    });
+    console.log(`Email sent to ${to}: ${info.messageId}`);
+    return info;
+  } catch (error) {
+    console.error('Error sending email:', error);
+    throw error;
+  }
+};
+
+module.exports = {
+  sendMail,
+  transporter
+};

backend/package.json

@@ -9,9 +9,11 @@
   "dependencies": {
     "bcrypt": "^5.1.1",
     "cors": "^2.8.5",
+    "dotenv": "^17.4.2",
     "express": "^4.18.2",
     "jsonwebtoken": "^9.0.2",
     "multer": "^1.4.5-lts.1",
+    "nodemailer": "^9.0.5",
     "sqlite3": "^5.1.7",
     "uuid": "^9.0.1"
   }