fix(agent-hooks): keep Orca's own CODEX_HOME out of the host probe

Orca exports CODEX_HOME/ORCA_CODEX_HOME for its managed Codex accounts. The probe inherited them, so it reported Orca's own account home as if the host user had redirected there — which broke the Node 18 managed-hook smoke and would have installed hooks into the managed account home on any client that runs the relay in-process. The child now gets the installer's HOME pinned and both variables stripped; a redirect the user's profile or launcher sets is unaffected, since the login shell re-exports it.

src/main/agent-hooks/codex-app-server-home-probe.test.ts

@@ -1,8 +1,11 @@
-import { afterEach, describe, expect, it } from 'vitest'
+import { afterEach, describe, expect, it, vi } from 'vitest'
 import { chmod, mkdtemp, rm, writeFile } from 'node:fs/promises'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
-import { probeCodexHomeViaAppServer } from './codex-app-server-home-probe'
+import {
+  buildCodexProbeEnvironment,
+  probeCodexHomeViaAppServer
+} from './codex-app-server-home-probe'
 
 // The probe speaks to a real child over pipes; `/bin/sh` is the shell it uses
 // on every host that reaches this code (Windows remotes never install hooks).
@@ -122,3 +125,46 @@ sleep 30
     expect(Date.now() - startedAt).toBeLessThan(5_000)
   })
 })
+
+describe('buildCodexProbeEnvironment', () => {
+  afterEach(() => {
+    vi.unstubAllEnvs()
+  })
+
+  it('drops the CODEX_HOME Orca injected for its own managed accounts', () => {
+    // Orca exports these for its managed Codex accounts. Reading one back would
+    // report Orca's own answer as if it were the host user's configuration.
+    vi.stubEnv('CODEX_HOME', '/orca/codex-accounts/abc/home')
+    vi.stubEnv('ORCA_CODEX_HOME', '/orca/codex-accounts/abc/home')
+
+    const env = buildCodexProbeEnvironment('/home/dev')
+
+    expect(env.CODEX_HOME).toBeUndefined()
+    expect(env.ORCA_CODEX_HOME).toBeUndefined()
+  })
+
+  it('pins HOME to the home the installer resolved', () => {
+    expect(buildCodexProbeEnvironment('/home/dev').HOME).toBe('/home/dev')
+  })
+
+  onPosix('asks Codex under the installer s home, not Orca s injected one', async () => {
+    vi.stubEnv('CODEX_HOME', '/orca/codex-accounts/abc/home')
+    const fake = await withFakeCodex(
+      `#!/bin/sh
+read -r _line
+home="\${CODEX_HOME:-$HOME/.codex}"
+printf '{"id":1,"result":{"codexHome":"%s"}}\\n' "$home"
+sleep 5
+`
+    )
+
+    await expect(
+      probeCodexHomeViaAppServer({
+        loginShell: '/bin/sh',
+        loginShellFlag: '-c',
+        env: { ...buildCodexProbeEnvironment('/home/dev'), PATH: fake.PATH },
+        timeoutMs: 10_000
+      })
+    ).resolves.toBe('/home/dev/.codex')
+  })
+})

src/main/agent-hooks/codex-app-server-home-probe.ts

@@ -20,6 +20,23 @@ const PROBE_TIMEOUT_MS = 12_000
 const MAX_STDOUT_BYTES = 64 * 1024
 const INITIALIZE_ID = 1
 
+/**
+ * The environment the probe hands the child.
+ *
+ * `HOME` is pinned to the home the installer resolved, so parent and child
+ * agree on which account is being configured. `CODEX_HOME`/`ORCA_CODEX_HOME`
+ * are dropped because Orca injects them for its own managed accounts — reading
+ * one back would report Orca's own answer as if it were the host user's. A
+ * value the user's profile or launcher wrapper sets is unaffected: the login
+ * shell re-exports it, which is the whole point of the probe.
+ */
+export function buildCodexProbeEnvironment(home: string): NodeJS.ProcessEnv {
+  const env: NodeJS.ProcessEnv = { ...process.env, HOME: home }
+  delete env.CODEX_HOME
+  delete env.ORCA_CODEX_HOME
+  return env
+}
+
 /**
  * `codex app-server` exits without answering when stdin reaches EOF, so the
  * request is written and the pipe is left open until the reply lands.

src/main/agent-hooks/managed-hook-runtime.ts

@@ -3,7 +3,10 @@ import { basename } from 'node:path'
 import { homedir, userInfo } from 'node:os'
 import { promisify } from 'node:util'
 import { installRemoteManagedAgentHooks } from './remote-managed-hook-installers'
-import { probeCodexHomeViaAppServer } from './codex-app-server-home-probe'
+import {
+  buildCodexProbeEnvironment,
+  probeCodexHomeViaAppServer
+} from './codex-app-server-home-probe'
 import type { AgentHookTarget } from '../../shared/agent-hook-types'
 import { createManagedHookLocalFilesystem } from './managed-hook-local-filesystem'
 import { withManagedHookInstallLock } from './managed-hook-install-lock'
@@ -109,6 +112,7 @@ export async function resolveRelayRedirectedCodexHome(
   const reported = await probe({
     loginShell: shell,
     loginShellFlag: flag,
+    env: buildCodexProbeEnvironment(home),
     ...(signal ? { signal } : {})
   })
   const codexHome = reported === null ? null : normalizePosixAgentHome(reported.trim())