v2.1.1 - Security fixes

Security fixes

• Fix reflected XSS via $_GET['s'] (esc_attr)
• Add current_user_can('manage_options') capability checks on all AJAX handlers
• Replace var_dump() with error_log() in API error handling
• Use intval() for numeric POST parameters
• Validate base64/JSON in lrseo_faq shortcode
• Guard update_post_meta with permission check