hardening: migrate RLIKE to db_qstr and improve input handling #761
Description
Summary
Migrate all RLIKE string interpolation to use db_qstr() for proper SQL quoting, and improve input handling across the plugin.
Changes
- Convert 11 RLIKE interpolation sites in notify_lists.php, thold.php, thold_graph.php to use db_qstr()
- Replace cacti_unserialize with sanitize_unserialize_selected_items in thold_webapi.php
- Apply html_escape to drp_action hidden form fields in notify_lists.php