Verify Email OTP Challenge

curl --request POST \
  --url https://api.authsignal.com/v1/client/verify/email-otp \
  --header 'Content-Type: application/json' \
  --data '{
  "verificationCode": "<string>"
}'

{
  "isVerified": true,
  "accessToken": "<string>",
  "failureReason": "CODE_INVALID_OR_EXPIRED"
}