Poland (KSeF) — VAT rounded at the total

Poland rounds VAT at the total, not per line. An invoice built with per-line rounding drifts by a cent and is rejected; the gate applies the country's policy explicitly.

• Applies total-level VAT rounding for a PL target and reports the policy it used.
• Validates NIP formats and checksums offline.
• States plainly that the national KSeF FA(3) XML is not emitted in v1 (EN 16931 CII/UBL only).