Hooks fail in git worktrees: $CLAUDE_PROJECT_DIR resolves to worktree, missing .claude/helpers/

Description

When Claude Code spawns an agent in a git worktree (via isolation: "worktree" or EnterWorktree), hooks configured in .claude/settings.json that reference $CLAUDE_PROJECT_DIR/.claude/helpers/ fail because $CLAUDE_PROJECT_DIR resolves to the worktree path, not the original repository root.

The .claude/ directory (including helpers/, settings.json, etc.) is not part of the git repository — it lives only in the main repo's working directory. Git worktrees do not copy or symlink non-tracked directories, so the helpers are missing in the worktree.

Reproduction

1. Have a project with hooks configured in .claude/settings.json that reference helper scripts:

``json
{
"hooks": {
"Stop": [{
"matcher": "",
"hooks": [{
"type": "command",
"command": "node \"$CLAUDE_PROJECT_DIR/.claude/helpers/auto-memory-hook.mjs\" sync"
}]
}]
}
}
``

1. Run Claude Code in a git worktree (either via isolation: "worktree" agent spawning, or EnterWorktree)

1. Observe hook failure:

```
Stop hook error: Failed with non-blocking status code: node:internal/modules/cjs/loader:1386
throw err;
^

Error: Cannot find module '/Users/user/project/.claude/worktrees/worktree-name/.claude/helpers/auto-memory-hook.mjs'
at Function._resolveFilename (node:internal/modules/cjs/loader:1383:15)
...
```

Expected Behavior

Hooks should resolve $CLAUDE_PROJECT_DIR to the original repository root (where .claude/ actually exists), not the worktree path. Alternatively, Claude Code could:

• Symlink .claude/ into the worktree on creation
• Provide a separate env var like $CLAUDE_ORIGINAL_PROJECT_DIR that always points to the main repo
• Fall back to the main repo's .claude/ when the worktree doesn't have one

Environment

• Claude Code version: latest (Claude Opus 4.6)
• Node.js: v22.22.0
• OS: macOS (Darwin 23.5.0)
• Git worktrees created under: <repo>/.claude/worktrees/