curl -X GET "https://api.adrelay.dev/v1/customer/me" \
  -H "X-API-Key: $ADRELAY_API_KEY"

{
  "id": "cust_abc123",
  "email": "dev@example.com",
  "plan": "pro",
  "created_at": "2026-03-01T12:00:00Z",
  "connections_count": 3,
  "stripe_customer_id": "cus_abc123"
}