refactor(opencode): remove app service layer exports (#34517)

packages/opencode/src/session/system.ts

@@ -47,7 +47,7 @@ export interface Interface {
 
 export class Service extends Context.Service<Service, Interface>()("@opencode/SystemPrompt") {}
 
-export const layer = Layer.effect(
+const layer = Layer.effect(
   Service,
   Effect.gen(function* () {
     const skill = yield* Skill.Service
@@ -128,12 +128,6 @@ export const layer = Layer.effect(
   }),
 )
 
-export const defaultLayer = layer.pipe(
-  Layer.provide(Skill.defaultLayer),
-  Layer.provide(MCP.defaultLayer),
-  Layer.provide(locationServiceMapLayer),
-)
-
 const locationServiceMapNode = LayerNode.make({
   service: LocationServiceMap.Service,
   layer: locationServiceMapLayer,