Better warnings for company customer contacts

When importing companies with customer contacts, things don’t always go smoothly – a customer might not exist yet, or they could already be linked to another company. Previously, these issues would either fail the import or be silently ignored. Now you get clear warnings explaining exactly what happened.

🔧 Improvements

• Customer not found – if a customer email or ID doesn’t match an existing customer, the import continues and shows which customer couldn’t be found (COMP026).
• Already linked to another company – when a customer is already associated with a different company, you’ll see a warning instead of a failure (COMP022).
• Catalog not found – location catalog assignments that can’t be resolved now warn rather than fail (COMP027).
• Main contact warnings – the same helpful warnings now apply when setting the company’s main contact.