- Email 2FA is now optional and disabled by default.

Existing and new accounts default to 2FA off.
Registration signs users in directly.
Users can enable it under My Account.
Administrators can manage it under Users & Staff.
Verified password-only and opted-in email-code login flows.
PHP/JavaScript checks and browser console passed.

views/account/index.php

@@ -43,6 +43,13 @@
                     <small>You can change this any time.</small>
                 </span>
             </label>
+            <label class="check-control">
+                <input type="checkbox" name="two_factor_enabled" value="1" <?= checked($currentUser['two_factor_enabled'] ?? 0) ?>>
+                <span>
+                    <strong>Use email two-factor authentication</strong>
+                    <small>Optional. When enabled, each sign-in requires a six-digit code sent to <?= e($currentUser['email']) ?>.</small>
+                </span>
+            </label>
             <details class="account-password">
                 <summary>Change password</summary>
                 <div class="form-stack">