test(opencode): simplify external directory layer wiring

packages/opencode/test/tool/external-directory.test.ts

@@ -2,6 +2,7 @@ import { PermissionV1 } from "@opencode-ai/core/v1/permission"
 import { describe, expect } from "bun:test"
 import path from "path"
 import { Effect } from "effect"
+import { LayerNode } from "@opencode-ai/core/effect/layer-node"
 import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
 import type { Tool } from "@/tool/tool"
 import { assertExternalDirectoryEffect } from "../../src/tool/external-directory"
@@ -11,7 +12,7 @@ import type { Permission } from "../../src/permission"
 import { SessionID, MessageID } from "../../src/session/schema"
 import { testEffect } from "../lib/effect"
 
-const it = testEffect(CrossSpawnSpawner.defaultLayer)
+const it = testEffect(LayerNode.buildLayer(CrossSpawnSpawner.node))
 
 const baseCtx: Omit<Tool.Context, "ask"> = {
   sessionID: SessionID.make("ses_test"),