diff --git a/examples/acp-agent/tests/fixtures/subagent/subagent-codex/cordis.yml b/examples/acp-agent/tests/fixtures/subagent/subagent-codex/cordis.yml
index cc50ea2587..f219214dd0 100644
--- a/examples/acp-agent/tests/fixtures/subagent/subagent-codex/cordis.yml
+++ b/examples/acp-agent/tests/fixtures/subagent/subagent-codex/cordis.yml
@@ -14,7 +14,7 @@
   config:
     env:
       OPENAI_API_KEY: !!js process.env.DSH_TEST_OPENAI_API_KEY
-      CODEX_HOME: !!js process.cwd() + '/codex-home'
+      CODEX_HOME: !!js process.env.DSH_TEST_CODEX_HOME
       HOME: !!js process.cwd()
       XDG_CONFIG_HOME: !!js process.cwd() + '/xdg'
       PATH: !!js process.env.PATH
diff --git a/examples/acp-agent/tests/snapshots/subagent-codex/evidence.expected.json b/examples/acp-agent/tests/product-provider-snapshots/codex/evidence.expected.json
similarity index 100%
rename from examples/acp-agent/tests/snapshots/subagent-codex/evidence.expected.json
rename to examples/acp-agent/tests/product-provider-snapshots/codex/evidence.expected.json
diff --git a/examples/acp-agent/tests/snapshots/subagent-codex/session.expected.jsonl b/examples/acp-agent/tests/product-provider-snapshots/codex/session.expected.jsonl
similarity index 100%
rename from examples/acp-agent/tests/snapshots/subagent-codex/session.expected.jsonl
rename to examples/acp-agent/tests/product-provider-snapshots/codex/session.expected.jsonl
diff --git a/examples/acp-agent/tests/subagent-product-providers.snapshot.ts b/examples/acp-agent/tests/subagent-product-providers.snapshot.ts
index 6df5b7f411..64d1d244ae 100644
--- a/examples/acp-agent/tests/subagent-product-providers.snapshot.ts
+++ b/examples/acp-agent/tests/subagent-product-providers.snapshot.ts
@@ -5,9 +5,10 @@
  * Code scenario and reruns both from its final stacked candidate.
  */
 
+import { homedir } from 'node:os'
 import { dirname, delimiter, join } from 'node:path'
 import { fileURLToPath } from 'node:url'
-import { mkdir, readFile, readdir, writeFile } from 'node:fs/promises'
+import { mkdir, mkdtemp, readFile, readdir, rm, writeFile } from 'node:fs/promises'
 import { describe, expect, it } from 'vitest'
 import {
   normalizeSessionLog,
@@ -25,7 +26,7 @@ const testsDir = dirname(fileURLToPath(import.meta.url))
 const repoRoot = fileURLToPath(new URL('../../..', import.meta.url))
 const fixtureDir = join(testsDir, 'fixtures/subagent/subagent-codex')
 const configPath = join(fixtureDir, 'cordis.yml')
-const snapshotDir = join(testsDir, 'snapshots/subagent-codex')
+const snapshotDir = join(testsDir, 'product-provider-snapshots/codex')
 const sessionExpected = join(snapshotDir, 'session.expected.jsonl')
 const evidenceExpected = join(snapshotDir, 'evidence.expected.json')
 const cliBin = join(repoRoot, 'packages/examples/cli-demo/src/bin.ts')
@@ -75,6 +76,7 @@ function responseInputTexts(body: Record<string, unknown>): string[] {
 
 describe('real product subagent providers through the Loader', () => {
   it('pins the Codex tool, result, persisted Session, and process quiescence', async () => {
+    const codexHome = await mkdtemp(join(homedir(), '.dsh-subagent-codex-loader-'))
     const responses = await startResponsesFixture([
       { kind: 'complete', text: CODEX_SENTINEL },
     ])
@@ -96,12 +98,11 @@ describe('real product subagent providers through the Loader', () => {
         tsconfigPath: repoTsconfig,
         processTimeoutMs: 45_000,
         env: {
+          DSH_TEST_CODEX_HOME: codexHome,
           DSH_TEST_OPENAI_API_KEY: FAKE_KEY,
           PATH: `${codexBinDir}${delimiter}${process.env.PATH ?? ''}`,
         },
-        async prepare(cwd): Promise<void> {
-          const codexHome = join(cwd, 'codex-home')
-          await mkdir(codexHome)
+        async prepare(): Promise<void> {
           await writeFile(join(codexHome, 'config.toml'), [
             'model = "fixture-model"',
             'model_provider = "fixture"',
@@ -161,7 +162,10 @@ describe('real product subagent providers through the Loader', () => {
       expect(normalizedSession).toBe(await readFile(sessionExpected, 'utf8'))
       expect(evidence).toBe(await readFile(evidenceExpected, 'utf8'))
     } finally {
-      await responses.close()
+      await Promise.all([
+        responses.close(),
+        rm(codexHome, { recursive: true, force: true }),
+      ])
     }
   }, LOADER_SMOKE_TEST_TIMEOUT_MS + 30_000)
 })
diff --git a/packages/subagent/subagent-codex/src/run.ts b/packages/subagent/subagent-codex/src/run.ts
index f58b0a6877..39bd5bcf27 100644
--- a/packages/subagent/subagent-codex/src/run.ts
+++ b/packages/subagent/subagent-codex/src/run.ts
@@ -65,16 +65,6 @@ export function textTask(prompt: readonly ContentBlock[]): string[] {
   return texts
 }
 
-async function treeExitsWithin(child: SubprocessHandle, ms: number): Promise<boolean> {
-  const controller = new AbortController()
-  const timer = setTimeout(() => { controller.abort() }, ms)
-  try {
-    return await child.waitForExit(controller.signal)
-  } finally {
-    clearTimeout(timer)
-  }
-}
-
 /**
  * Close the private wire, terminate the managed process tree, and wait for the
  * subprocess owner to prove it is gone.
@@ -98,7 +88,7 @@ export async function disposeCodexChild(
     // A concurrently closed stdin does not change tree ownership below.
   }
   child.terminate()
-  if (!(await treeExitsWithin(child, graceMs * 2))) {
+  if (!(await child.waitForExit(AbortSignal.timeout(graceMs * 2)))) {
     throw new Error('subagent-codex: app-server process tree did not exit within its dispose window')
   }
   await child.done