Test Runner Error Output Not Displayed

Bug Description
Claude seems to be unable to see stderr output. If I tell it to run something like vitest via yarn, eg I have a "script" key for "test" in my package.json that calls "vitest run", if the tests then fail it has an exit code of -1 but claude does not show the error output and so doesn't know why the tests are failing.

// package.json
{
  "scripts": { 
      "test": "vitest run"
   }
}

● Let's try running the tests now:

● Bash(yarn test)…
  ⎿  Exit code 1

● Let's try a more specific command to see if we can get the error output:

Might be related/same to #116

Environment Info

• Platform: linux
• Terminal: gnome-terminal
• Version: 0.2.29
• Feedback ID: 8b8de3d6-ffd8-440c-a66a-a4eba24d84b0