Validate the customer's credentials and retrieve tenant information.

This operation verifies that the credentials provided by the customer are valid and active.
It also retrieves identifying information about the customer's tenant/organization in the
integrated application.

The credentials could have been obtained through various means, such as:

• OAuth flow
• API keys
• Username/password
• Service account credentials

This endpoint should be called:

• After obtaining new credentials to verify they work
• Before performing other operations to ensure credentials are still valid
• To get the tenant identifier needed for other operations