Initial commit: teaching institution management API.

Express/MongoDB backend with JWT auth, RBAC, S3 uploads, notifications, and scheduled jobs.

utils/credentials.js

@@ -0,0 +1,27 @@
+// /utils/credentials.js
+'use strict';
+
+const crypto = require('crypto');
+
+const LETTERS = 'abcdefghijkmnpqrstuvwxyz';
+const DIGITS = '23456789';
+
+const randomFrom = (alphabet, length) => {
+  let out = '';
+  const bytes = crypto.randomBytes(length);
+  for (let i = 0; i < length; i += 1) {
+    out += alphabet[bytes[i] % alphabet.length];
+  }
+  return out;
+};
+
+/** Simple password: exactly 2 English letters + 4 digits (e.g. kx4821) */
+const generateSimplePassword = () => `${randomFrom(LETTERS, 2)}${randomFrom(DIGITS, 4)}`;
+
+/** Random username: u + 6 digits (e.g. u482910) */
+const generateUsername = () => `u${randomFrom(DIGITS, 6)}`;
+
+module.exports = {
+  generateSimplePassword,
+  generateUsername,
+};