refactor(core): remove unreferenced layer map example (#39971)

Co-authored-by: Kit Langton <kit.langton@gmail.com>

packages/core/src/plugin/layer-map.example.ts

@@ -1,94 +0,0 @@
-export * as LayerMapExample from "./layer-map.example"
-
-import { Context, Effect, Layer, LayerMap } from "effect"
-import { Npm } from "@opencode-ai/util/npm"
-
-/**
- * Tutorial: split global services from context-specific services.
- *
- * Use this pattern when part of the app should be constructed once at the app edge,
- * while another part should be cached per request/project/workspace key.
- *
- * In this example:
- * - Npm.Service is the global service. It is not keyed by request context and should
- *   be provided once by the application runtime.
- * - ConfigService is context-specific. It is built from a RequestContext key and is
- *   cached by LayerMap for that key.
- * - ConfigServiceMap.layer owns the cache. Provide it once globally, then each
- *   request can provide ConfigServiceMap.get(context) to select the right instance.
- *
- * Lifetime model:
- * - ConfigServiceMap.layer has the app/global lifetime and depends on Npm.Service.
- * - ConfigServiceMap.get(context) has the request/context lifetime and provides
- *   ConfigService for exactly that context key.
- * - The cached ConfigService entry stays alive while something is using it. Once idle,
- *   it remains cached for idleTimeToLive, then its scope is finalized.
- * - invalidate(context) removes the cache entry for future lookups. Active users keep
- *   running on the old instance; the next lookup can create a fresh instance.
- *
- * Key model:
- * - Keys can be strings, structs, classes, arrays, etc.
- * - Prefer primitive or immutable keys. Effect uses Hash / Equal semantics for cache
- *   lookup, so mutating an object after it has been used as a key is a bug.
- */
-
-export type RequestContext = {
-  readonly directory: string
-  readonly workspace: string
-}
-
-export class RequestContextRef extends Context.Service<RequestContextRef, RequestContext>()(
-  "@opencode/example/RequestContextRef",
-) {}
-
-export interface ConfigServiceShape {
-  readonly directory: string
-  readonly workspace: string
-  readonly nextUse: () => Effect.Effect<number>
-  readonly which: Npm.Interface["which"]
-}
-
-export class ConfigService extends Context.Service<ConfigService, ConfigServiceShape>()(
-  "@opencode/example/ConfigService",
-) {}
-
-const configServiceLayer = Layer.effect(
-  ConfigService,
-  Effect.gen(function* () {
-    const context = yield* RequestContextRef
-    const npm = yield* Npm.Service
-
-    let useCount = 0
-
-    return ConfigService.of({
-      directory: context.directory,
-      workspace: context.workspace,
-      nextUse: () => Effect.succeed(++useCount),
-      which: npm.which,
-    })
-  }),
-)
-
-export class ConfigServiceMap extends LayerMap.Service<ConfigServiceMap>()("@opencode/example/ConfigServiceMap", {
-  lookup: (context: RequestContext) =>
-    configServiceLayer.pipe(Layer.provide(Layer.succeed(RequestContextRef, RequestContextRef.of(context)))),
-  idleTimeToLive: "5 minutes",
-}) {}
-
-export const appLayer = ConfigServiceMap.layer
-
-export const readConfig = Effect.fn("LayerMapExample.readConfig")(function* () {
-  const config = yield* ConfigService
-
-  return {
-    directory: config.directory,
-    workspace: config.workspace,
-    useCount: yield* config.nextUse(),
-  }
-})
-
-export const handleRequest = Effect.fn("LayerMapExample.handleRequest")(function* (context: RequestContext) {
-  return yield* readConfig().pipe(Effect.provide(ConfigServiceMap.get(context)))
-})
-
-export const invalidateContext = (context: RequestContext) => ConfigServiceMap.invalidate(context)