Feature Request: Enhance Contact Person Management

The client, Willem-Dirk van ’t Veer of Wolfswinkel Infra, has submitted a feature request regarding contact management. They propose two key improvements:

1. Linking to multiple clients:
   The ability to link a single contact to multiple clients/contractors. This is requested because many contractors (self-employed professionals) work for different companies and partnerships. This currently leads to a proliferation of duplicate contacts and causes confusion in the system.

2. Access via the main menu:
   A dedicated section for contacts in the main menu, so that their contact details, such as phone numbers and email addresses, are more easily accessible.