Add OTP_REQUIRED switch for email OTP login

app/login/index.php

@@ -1,6 +1,7 @@
 <?php 
   require '../session.php';
   require '../config.php';
+  require_once '../assets/utils/otp_policy.php';
   require '../include_header.php';
   // successful login — redirect based on app_access
   if(!empty($_SESSION["login_status"])){
@@ -32,6 +33,13 @@
         </div>
 
         <form class="needs-validation mt-3" novalidate id="login-form">
+          <?php if (!otp_required()): ?>
+          <!-- OTP_REQUIRED=false in config.php: a weakened sign-in must never be invisible -->
+          <div class="alert alert-warning small py-2 mb-3" title="OTP_REQUIRED=false in config.php">
+            <i class="ti ti-alert-triangle me-1"></i>
+            Email OTP is temporarily disabled — sign-in is password only.
+          </div>
+          <?php endif; ?>
           <!-- first step login [OTP] -->
           <?php if(!isset($_SESSION['login_data'])){?>
           <div class="mb-3">
@@ -51,7 +59,7 @@
 
           <div class="d-flex justify-content-between align-items-center mb-3">
             <!-- "Remember me" is intentionally excluded.
-            This login uses 2FA (OTP via email) on every session.
+            This login uses 2FA (OTP via email) on every session, unless OTP_REQUIRED=false in config.php.
             A persistent login would bypass the OTP step and undermine the security model.
             Do not add this back. -->
           </div>
@@ -62,6 +70,7 @@
           </p>
           <?php }else{ ?>
           <!-- second step login  -->
+          <?php if (otp_required()): ?>
           <div class="alert alert-warning small py-2 mb-3">
             <i class="ti ti-mail me-1"></i>
             OTP is sent via your company's SMTP setting.
@@ -73,13 +82,20 @@
               <span>One Time Password</span>
             </label>
             <input id="otp" type="otp" class="form-control"
-              placeholder="your otp for reference number <?php echo $_SESSION["reference"]?>" required minlength="6">
+              placeholder="your otp for reference number <?php echo $_SESSION["reference"] ?? ''?>" required minlength="6">
             <div class="invalid-feedback">Please provide a otp (min 6 characters).</div>
           </div>
+          <?php else: ?>
+          <!-- OTP_REQUIRED was switched off while this session sat on the OTP step:
+               login_confirm.php no longer checks the code, so there is nothing to type. -->
+          <input id="otp" type="hidden" value="">
+          <?php endif; ?>
           <div class="mb-3">
             <label for="password" class="form-label d-flex justify-content-between">
               <a href="javascript:;" class="small link-primary" onclick="back()">Back</a>
+              <?php if (otp_required()): ?>
               <a href="javascript:;" class="small link-primary" onclick="request_new_otp();">Request New OTP</a>
+              <?php endif; ?>
             </label>
           </div>
           <button class="btn btn-primary w-100" onclick="login_confirm();">Sign in</button>