Fase produccion: alinear plantilla fiscal con campos de impuestos

Actualiza invoice.fodt para usar itbis_invoiced_line y tip_invoiced tras la normalizacion de campos. Agrega prueba de regresion para evitar referencias al campo heredado itbis_line.

tests/test_module.py

@@ -1,5 +1,6 @@
 import datetime
 from decimal import Decimal
+from pathlib import Path
 from types import SimpleNamespace
 import unittest
 
@@ -221,6 +222,15 @@ del ModuleTestCase
 
 class NcfManagerUnitTestCase(unittest.TestCase):
 
+    def test_invoice_report_uses_current_tax_field_names(self):
+        path = Path(__file__).parents[1] / 'invoice.fodt'
+        template = path.read_text(encoding='utf-8')
+
+        self.assertNotIn('line.itbis_line', template)
+        self.assertEqual(template.count('line.itbis_invoiced_line'), 2)
+        self.assertEqual(template.count('if test="invoice.tip_invoiced'), 2)
+        self.assertEqual(template.count('format_currency(invoice.tip_invoiced'), 2)
+
     def test_sequence_defaults_match_ncf_type(self):
         sequence = SimpleNamespace(
             sequence_type=SimpleNamespace(name='Factura de Crédito Fiscal'))