post https://kigo-core-server-test.kigodigital.net/api/v1/members/enroll
This endpoint handles the process of enrolling a user in the rewards network by:
- Checking if the user is already enrolled
 - If not enrolled, generating a unique member ID
 - Sending the enrollment request to the rewards network service
 - Storing the member ID in our database to track the enrollment
 
The flow handles several cases:
- New member enrollment (201 Created)
 - Member reactivation (200 OK)
 - Already active member (409 Conflict)
 - Various error cases (400, 500)
 
Returns a success response with the member ID and status, or an appropriate error if the enrollment fails at any step.