Public API: Endpoint for internal (MSP) users

Description:

We use the Public API for internal account auditing, and would like to retrieve a list of internal Salesbuildr users (Settings > Users & Access > Users), not customer/relationship contacts.

The current /public-api/contact endpoint only returns customer facing contacts. There is no equivalent endpoint for internal users.

Requested attributes:

userId, name, email, active/inactive status (allowLogin), roles, last login timestamp.

Use case:

Periodic internal account audits, to verify which employees have an active Salesbuildr account, independent of whether they also exist as a contact record.

Additional considerations:

Should support pagination consistent with other list endpoints.