! (bash mode) commands produce no output for filesystem commands

Description

Commands run with the ! prefix (bash mode) produce no output for filesystem-accessing commands, while non-filesystem commands work fine.

Steps to reproduce

1. Open Claude Code in any project directory
2. Run ! echo hallo → output is displayed correctly: hallo
3. Run ! ls -la → output shows only: (Bash completed with no output)
4. Run ! eza -l → same: (Bash completed with no output)

The same commands work correctly when executed via the Bash tool within the conversation.

What I've ruled out

• Sandbox: Disabled sandbox via /sandbox toggle — same behavior
• Permissions: Ran with --dangerously-skip-permissions — same behavior
• Directory: Tested in multiple directories (~/Repos/GeoServer-Tools/, ~/plan/) — same behavior
• Sandbox filesystem config: The directories are not in denyRead, and allowWrite includes "./" (project root)

Expected behavior

! ls -la should display the directory listing in the conversation, as documented for bash mode.

Actual behavior

! ls -la completes silently with (Bash completed with no output). No error, no stderr, no stdout.

Environment

• macOS (Darwin 25.4.0)
• Claude Code stable channel
• Sandbox enabled with autoAllowBashIfSandboxed: true