Complete authentication

curl -X POST https://api.useknot.xyz/connect/complete \
  -H "Content-Type: application/json" \
  -d '{
    "email": "agent@example.com",
    "otpId": "550e8400-e29b-41d4-a716-446655440000",
    "otpCode": "123456"
  }'

{
  "status": true,
  "statusCode": 200,
  "message": "Authentication successful. Wallet created.",
  "data": {
    "apiToken": "eyJhbGciOiJIUzI1NiIs...",
    "solanaAddress": "7xKXtg2CW87d97TXJSDpbD5jBkheTqA83TZRuJosgAsU",
    "username": "agent_abc123",
    "isNewAgent": true
  }
}