- Preserve source ticket ID as string (ctype_digit validation)
instead of int-casting with (int)
- Use $sourceTicket['ticket_id'] (canonical DB form) when creating
the relates_to dependency and audit log entry; avoids storing
"123456" instead of "000123456" which breaks string-based
depends_on_id lookups in DependencyModel
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>