Unified contacts model: Rentman-style type field (company/person), inline addresses, ContactPerson 1:N, all Rentman fields except rental-specific

app/services/import_export_service.py

@@ -11,10 +11,10 @@ from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.audit import log_audit
-from app.models.company import Company
-from app.models.contact import Contact
+from app.models.contact import Contact, ContactPerson as Company
+from app.models.contact import Contact, ContactPerson
 from app.services.company_service import _company_to_dict
-from app.services.contact_service import _contact_to_dict
+from app.services.contact_service import _serialize_contact as _contact_to_dict
 
 # Expected CSV columns for each entity type
 COMPANY_COLUMNS = ["name", "industry", "phone", "email", "website", "description"]