delete runtime mapping, normalizations, revalidations

[Yostra]

Summary

Cleanup follow-ups from PR #352:

• Drop static alias maps. OPENAPI_RESOURCE_TABLE_ALIASES,
  STRIPE_OBJECT_TO_SYNC_OBJECT_ALIASES, and normalizeStripeObjectName
  removed. resolveTableName no longer merges a hidden default; tables derive
  from x-resourceId (. → _, lowercase).
  • radar.early_fraud_warning → radar_early_fraud_warning
  • entitlements.active_entitlement → entitlements_active_entitlement
  • entitlements.feature → entitlements_feature (was colliding with
    active_entitlement)
• Remove webhook revalidation. revalidate_objects config,
  REVALIDATE_ENTITIES, RevalidateEntityName, ResourceConfig.isFinalState,
  and the re-fetch branch in processStripeEvent are gone. processStripeEvent
  no longer takes Config. Events polling + destination _updated_at guards
  cover the original race.
• Delete dead prefix helpers. PREFIX_RESOURCE_MAP,
  getResourceFromPrefix, getResourceConfigFromId, and getTableName had no
  callers; events route via event.data.object.object, not ID prefixes.
• Conformance test: accept top-level anyOf config schemas
  (source-postgres, destination-stripe).