Zalktis: SQL injection via partner-controlled fields in imported e-invoices

SQL injection in the Zalktis accounting application via
trading-partner-controlled text fields in received electronic invoices. When
importing a received e-invoice (UBL/PEPPOL) or an e-commerce export, Zalktis
concatenates partner-controlled values directly into SQL statement text using
string concatenation, with neither parameterised queries nor escaping. The
application's own escaping helper, Dazadi.sql_txt(),
is not invoked on these code paths, so a party that sends an invoice can break
out of the string literal and alter the query logic.

This issue affects Zalktis: before 2026.1.586 and before 2026.2.592.