<ul><li>Fixed <code>index.php</code> lines 13 and 54: <code>$_SESSION[super_admin]</code> undefined array key — added <code>?? 0</code> null coalescing on both super_admin checks</li><li>Fixed <code>LeadsController.php</code> <code>getAllLeads()</code>: <code>$params[filtered_value]</code> undefined key — added <code>?? 0</code>; <code>$data_paginations[paginations]</code> undefined variable (never initialized in this function) — replaced with empty string</li><li>Fixed <code>LeadsController.php</code> <code>assignLead()</code>: <code>$params[type]</code> undefined array key on line 455 — added <code>?? </code>; changed <code>isset($type)</code> to <code>!empty($type)</code> since type is always set after fix</li><li>Fixed <code>assignLead()</code> else-branch: <code>$assign_data[type]</code> null offset on lines 521/535/554 — extracted to <code>$assign_type = $assign_data[type] ?? </code> and replaced all three references</li><li>Fixed <code>assignLead()</code> else-branch: <code>$user[name]</code> and <code>$user[profile_pic]</code> null offset on lines 551/552 — added <code>?? </code> on both</li></ul>