[BUG] Sandbox blocks git checkout / worktree add on repos tracking .vscode/ — intended?

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's Wrong?

Trying to git worktree add from a monorepo that tracks .vscode/settings.json. The sandbox denies writing .vscode/settings.json during checkout; the worktree add fails mid-operation, leaving a stale branch + worktree registration that requires git worktree prune + git branch -D to clean up.

The block isn't in any visible settings file — it's hardcoded in the binary. Is this intended? If blocking writes to tracked .vscode/* / .idea/* (common in shared monorepos that standardize format/lint settings) is a deliberate security tradeoff, that's worth documenting + providing an opt-out for. If unintended, explicit sandbox.filesystem.allowWrite entries should win over the hardcoded list so git checkout works on any user-allowlisted repo.

What Should Happen?

git checkout / git worktree add should succeed on any repo under a user-allowlisted allowWrite root, regardless of whether the repo tracks .vscode/*.

Error Messages/Logs

operation not permitted: /Users/xida/monorepo/t/.vscode/x.json

Steps to Reproduce

1. ~/.claude/settings.json:

``json
{"sandbox": {"enabled": true, "filesystem": {"allowWrite": ["~/monorepo/"]}}}
``

1. Have a repo under ~/monorepo/ that tracks .vscode/settings.json.
2. git -C ~/monorepo/main worktree add ../feature-x -b feature-x main → fails mid-checkout; branch + registration created but directory incomplete. Recovery: git worktree prune + git branch -D feature-x.

Narrow repro (sandboxed Bash):

$ printf '{}' > ~/monorepo/t/.vscode/x   # operation not permitted
$ printf '{}' > ~/monorepo/t/.idea/x     # operation not permitted
$ printf '{}' > ~/monorepo/t/foo         # ok
$ printf '{}' > ~/monorepo/t/.git/x      # ok (not blocked)

Claude Model

Not applicable (sandbox behavior, not model-dependent)

Is this a regression?

I don't know

Claude Code Version

2.1.114

Platform

Anthropic API

Operating System

macOS (Darwin 24.6.0)

Terminal/Shell

iTerm2

Additional Information

v2.1.114 binary strings show .vscode, .idea hardcoded near the _SBX module, distinct from the home-dir-mapping dotfile set (.bashrc, .gitconfig, .mcp.json, …) discussed in #29316. Related: #29316, #50505.