fix(headless): dsh run is a direct core front door

apps/cli/tests/fixtures/never-dispose.mjs

@@ -8,6 +8,7 @@ import { existsSync } from 'node:fs'
  */
 export function apply(ctx) {
   const keepAlive = setInterval(() => {}, 60_000)
+  process.stderr.write('dsh-test: never-dispose ready\n')
   ctx.effect(() => async () => {
     clearInterval(keepAlive)
     const armFile = process.env.DSH_TEST_SHUTDOWN_ARM_FILE