curl -X POST 'https://app.memorylake.cn/openapi/memorylake/api/v3/db-connections/connectivity-test' \
  -H 'Authorization: Bearer sk_xxxxxx' \
  -H 'Content-Type: application/json' \
  -d '{
    "host": "pg.internal.example.com",
    "port": 5432,
    "database": "sales",
    "username": "analytics_ro",
    "password": "your-database-password"
  }'

{
  "success": true,
  "data": {
    "schemas": ["public", "sales"]
  }
}

{
  "success": false,
  "message": "[CONNECTION_FAILED] Database connection failed",
  "error_code": "DB_CONNECTION_FAILED"
}