[BUG] /sandbox seccomp filter instructions don't work, paths not read from settings

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?

/sandbox reports that seccomp filter is not installed, despite the files present in the system and configured in settings.json:

$jq . ~/.claude/settings.json
{
  "applyPath": "/usr/lib/claude-code-seccomp/apply-seccomp",
  "sandbox": {
    "seccomp": {
      "bpfPath": "/usr/lib/claude-code-seccomp/vendor/seccomp/x64/unix-block.bpf",
      "applyPath": "/usr/lib/claude-code-seccomp/vendor/seccomp/x64/apply-seccomp"
    }
  }
}
$ls /usr/lib/claude-code-seccomp/vendor/seccomp/x64/
 apply-seccomp   unix-block.bpf

What Should Happen?

seccomp filter dependency should show as installed

Error Messages/Logs

Sandbox:  Mode   Dependencies   Overrides   Config  (←/→ or tab to cycle)


 bubblewrap (bwrap): installed

 socat: installed

 seccomp filter: not installed (required to block unix domain sockets)
   · npm install -g @anthropic-ai/sandbox-runtime
   · or copy vendor/seccomp/* from sandbox-runtime and set
     sandbox.seccomp.bpfPath and applyPath in settings.json

Steps to Reproduce

1. configure as above
2. claude /sandbox and navigate right to dependencies

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.37 (Claude Code)

Platform

Anthropic API

Operating System

Other Linux

Terminal/Shell

Other

Additional Information

_No response_