src/lib/<adt-name>/
├── _.ts              # export * as AdtName from './__.js'
├── __.ts             # exports member namespaces + union
├── <adt-name>.ts     # Union definition
├── <member-a>.ts     # Member type
└── <member-b>.ts     # Member type

// <member>.ts
import * as S from 'effect/Schema'

export class MemberName extends S.TaggedClass<MemberName>()('AdtNameMemberName', {
  // fields...
}) {
  static is = S.is(MemberName)
}

// <adt-name>.ts
import * as S from 'effect/Schema'
import { MemberA } from './member-a.js' // Direct import, NOT from __.ts
import { MemberB } from './member-b.js'

export const AdtName = S.Union(MemberA, MemberB)
export type AdtName = typeof AdtName.Type

// __.ts
export * from './<adt-name>.js'
export * as MemberA from './member-a.js'
export * as MemberB from './member-b.js'

// added.ts
export class Added extends S.TaggedClass<Added>()('LifecycleEventAdded', {
  schema: SchemaRef,
  revision: Revision,
}) {
  static is = S.is(Added)
}

// removed.ts
export class Removed extends S.TaggedClass<Removed>()('LifecycleEventRemoved', {
  schema: SchemaRef,
  revision: Revision,
}) {
  static is = S.is(Removed)
}

// lifecycle-event.ts
import { Added } from './added.js'
import { Removed } from './removed.js'
export const LifecycleEvent = S.Union(Added, Removed)
export type LifecycleEvent = typeof LifecycleEvent.Type

// __.ts
export * as Added from './added.js'
export * from './lifecycle-event.js'
export * as Removed from './removed.js'

// _.ts
export * as LifecycleEvent from './__.js'

// Import ONLY from namespace (_.js)
import { LifecycleEvent } from '#lifecycle-event'

// Access members via namespace
const added = LifecycleEvent.Added.make({ schema, revision })
const removed = LifecycleEvent.Removed.make({ schema, revision })

// Type check
if (LifecycleEvent.Added.is(event)) {
  // event is Added
}