fix(sync): allow kit components with price=0 to import

Price=0 is a valid state for kit components in crm_politici_pret_art,
inserted automatically by the price sync system. Previously, the kit
validation treated pret=0 the same as missing, blocking orders from
importing even when all SKU mappings were correctly configured.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/app/services/validation_service.py

@@ -466,7 +466,7 @@ def validate_kit_component_prices(mapped_codmat_data: dict, id_pol: int,
                         WHERE id_pol = :pol AND id_articol = :id_art
                     """, {"pol": pol, "id_art": comp["id_articol"]})
                     row = cur.fetchone()
-                    if not row or (row[0] is not None and row[0] == 0):
+                    if not row:
                         sku_missing.append(comp["codmat"])
                 if sku_missing:
                     missing[sku] = sku_missing