This endpoint allows a workspace owner to invite a new team member to their workspace by email.
The system checks for any existing pending invitation for the same email to prevent duplicates.
A new invitation record is created and stored with a 7-day expiration.
An invitation email is sent to the invitee with a secure link to accept the invitation.
If the workspace is configured in agency mode with white-label settings, the invitation email will be sent using the workspace’s verified custom email (if available).