refactor(agent-hooks): launch the WSL hook relay through the process host (#34051)

Build the wsl.exe argv with buildWslExecArgs and start it with spawnProcess
from @orca/process-host instead of a hand-built node:child_process spawn.

src/main/agent-hooks/wsl-hook-relay-launch.test.ts

@@ -1,18 +1,21 @@
 import { describe, expect, it, vi } from 'vitest'
 import { execFileSync } from 'node:child_process'
-import type * as ChildProcess from 'node:child_process'
+import type * as ProcessHost from '@orca/process-host'
 import { chmodSync, mkdirSync, mkdtempSync, rmSync, writeFileSync } from 'node:fs'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { resetWslInteropSpawnDirectoryCache } from '../wsl-interop-spawn-directory'
 
-const { spawnMock } = vi.hoisted(() => ({
-  spawnMock: vi.fn((..._args: unknown[]) => ({ pid: 1 }))
+const { spawnProcessMock } = vi.hoisted(() => ({
+  spawnProcessMock: vi.fn((..._args: unknown[]) => ({ pid: 1 }))
 }))
 
-vi.mock('node:child_process', async (importOriginal) => ({
-  ...(await importOriginal<typeof ChildProcess>()),
-  spawn: spawnMock
+vi.mock('@orca/process-host', async (importOriginal) => ({
+  ...(await importOriginal<typeof ProcessHost>()),
+  spawnProcess: spawnProcessMock
+}))
+vi.mock('../wsl/wsl-executable-path', () => ({
+  resolveWslExecutablePath: () => 'C:\\Windows\\System32\\wsl.exe'
 }))
 
 import {
@@ -31,9 +34,9 @@ describe('spawnWslRelayProcess', () => {
     try {
       spawnWslRelayProcess('Ubuntu', env, '1.2.3')
 
-      expect(spawnMock).toHaveBeenCalledExactlyOnceWith(
-        'wsl.exe',
-        [
+      expect(spawnProcessMock).toHaveBeenCalledExactlyOnceWith({
+        program: 'C:\\Windows\\System32\\wsl.exe',
+        args: [
           '-d',
           'Ubuntu',
           '--exec',
@@ -41,8 +44,10 @@ describe('spawnWslRelayProcess', () => {
           '-c',
           'exec sh "$HOME/.orca-wsl/hook-relay/1.2.3/launch.sh"'
         ],
-        { env, stdio: ['pipe', 'pipe', 'pipe'], windowsHide: true, cwd: systemRoot }
-      )
+        env,
+        stdio: 'pipe',
+        cwd: systemRoot
+      })
     } finally {
       vi.unstubAllEnvs()
       resetWslInteropSpawnDirectoryCache()

src/main/agent-hooks/wsl-hook-relay-launch.ts

@@ -1,6 +1,7 @@
-import { spawn, type ChildProcessWithoutNullStreams } from 'node:child_process'
+import type { ChildProcessWithoutNullStreams } from 'node:child_process'
 import { existsSync, readFileSync } from 'node:fs'
 import { join } from 'node:path'
+import { spawnProcess } from '@orca/process-host'
 import { relayBundleCandidates } from '../ssh/relay-bundle-paths'
 import { withWslGuestLauncherRevision } from '../wsl/wsl-guest-launcher-revision'
 import { orcadPosixNodeRuntimeGlobs } from '../managed-server/install/orcad-node-runtime-globs'
@@ -13,6 +14,8 @@ import {
 } from './wsl-hook-relay-sentinel'
 import { addOrcaWslInteropEnv } from '../pty/wsl-orca-env'
 import { runWslProcess } from '../wsl/wsl-runner'
+import { resolveWslExecutablePath } from '../wsl/wsl-executable-path'
+import { buildWslExecArgs } from '../../shared/wsl-login-shell-command'
 import { resolveWslInteropSpawnCwd } from '../wsl-interop-spawn-directory'
 import {
   WSL_HOOK_RELAY_BUNDLE_NAME,
@@ -102,10 +105,11 @@ export function spawnWslRelayProcess(
 ): ChildProcessWithoutNullStreams {
   // --exec bypasses login-shell rewriting and passes $HOME verbatim for guest-side expansion.
   const command = `exec sh "${guestRelayDirExpr(version)}/launch.sh"`
-  return spawn('wsl.exe', ['-d', distro, '--exec', 'sh', '-c', command], {
+  return spawnProcess({
+    program: resolveWslExecutablePath(),
+    args: buildWslExecArgs(distro, ['sh', '-c', command]),
     env,
-    stdio: ['pipe', 'pipe', 'pipe'],
-    windowsHide: true,
+    stdio: 'pipe',
     // Use a stable Windows cwd so deleting the current worktree cannot break later relay launches.
     cwd: resolveWslInteropSpawnCwd()
   })