- delete_attachment.php: add realpath() path traversal check before
unlink() — mirrors the defense-in-depth already in download_attachment.php;
also cast ticket_id to int when building the path
- manage_templates.php: add input validation to POST and PUT handlers:
required field checks, max length caps (name 100, title 255, desc 64KB),
allowlist validation for category/type, priority clamped to 1-5
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>