[BUG] Fullscreen TUI: failed Bash tool output is empty when expanded

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

In fullscreen TUI mode (/tui fullscreen), when a Bash tool call fails (non-zero exit code), expanding the tool call shows the command but no output — the stdout and exit code indicator are missing. Successful Bash calls display their output correctly when expanded.

The classic/default TUI renderer does NOT have this issue — it correctly shows Error: Exit code 1 along with the command output.

What Should Happen?

Expanding a failed Bash tool call should show the output and exit code, same as in classic mode:

⏺ Bash(echo "This command fails" && exit 1)
  ⎿  Error: Exit code 1
     This command fails

Steps to Reproduce

1. Enable fullscreen TUI mode (/tui fullscreen)
2. Have Claude run a bash command that fails, e.g. echo "This command fails" && exit 1
3. Click to expand the tool call

Actual rendering in fullscreen (expanded):

⏺ Bash(echo "This command fails" && exit 1)

(no output shown)

Rendering in classic/default TUI (expanded) — correct:

⏺ Bash(echo "This command fails" && exit 1)
  ⎿  Error: Exit code 1
     This command fails

Error Messages/Logs

No error messages — the output is silently not rendered.

Claude Model

Opus

Is this a regression?

I don't know

Claude Code Version

2.1.159 (Claude Code)

Platform

Other

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

• macOS 26.5 (Darwin 25.5.0)
• Fullscreen TUI mode only — classic renderer works correctly
• Successful Bash tool calls display output correctly in both modes; only failed calls (non-zero exit) have missing output in fullscreen