{
  "email": "newmember@example.com",
  "role": "member"
}

{
  "success": true,
  "message": "Invitation sent successfully",
  "invitation": {
    "id": "550e8400-e29b-41d4-a716-446655440000",
    "email": "newmember@example.com",
    "role": "member",
    "status": "pending",
    "sent_at": "2025-11-27T10:30:00Z"
  }
}