Activate (or reactivate) an existing user account.

This operation allows you to activate or reactivate a user account that exists in the third-party system.
The behavior depends on how the specific connector implements account activation/deactivation.

Common use cases include:

• Enabling user account access to the third-party system
• Reactivating a previously deactivated account
• Enabling a suspended account
• Completing account setup after initial creation