v0.0.27

• Expose variant, errorMessage, and flagMetadata on EvaluationDetails, plumbing internal
  evaluation metadata (configId, configType, ruleIndex, weightedValueIndex, environment)
  through to the public details API per the cross-SDK spec
  (project/plans/openfeature-resolution-details.md). configType values are SHOUTY_SNAKE,
  metadata keys are camelCase, and environment is read from QUONFIG_ENVIRONMENT (qfg-9dbl).
• Add isEnabled(key, contexts?) as the canonical flag-check method on both Quonfig and
  BoundQuonfig, aligning sdk-node with @quonfig/javascript and @quonfig/react.
  isFeatureEnabled remains as a @deprecated passthrough so existing callers (including code
  migrated from the Reforge launch SDK) keep working unchanged (qfg-rp6t).
• Bump engines.node floor to >=20.9.0. Node 18 hit EOL on 2025-04-30, and 20.9.0 is the
  strictest 20.x floor any installed dep currently requires. CI matrix drops Node 18 and pins the
  lowest entry to 20.9.0 (qfg-y7xh).