Worktree: $CLAUDE_PROJECT_DIR hooks can't find .claude/helpers/ files

Summary

When Claude Code spawns a git worktree (via the EnterWorktree tool or isolation: "worktree" agents), hooks defined in settings.json that reference $CLAUDE_PROJECT_DIR/.claude/helpers/ fail with MODULE_NOT_FOUND because the .claude/ directory is not copied or symlinked into the worktree.

Reproduction

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

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

1. Place helper scripts in .claude/helpers/ (e.g. auto-memory-hook.mjs, hook-handler.cjs)
2. Start a session in a worktree (e.g. /.claude/worktrees/bubbly-questing-hopper/)
3. Trigger any hook — it fails:

Error: Cannot find module '/Users/paul/code/universeos/.claude/worktrees/bubbly-questing-hopper/.claude/helpers/auto-memory-hook.mjs'
    at Function._resolveFilename (node:internal/modules/cjs/loader:1383:15)
    ...
    code: 'MODULE_NOT_FOUND'

Expected behavior

Hooks using $CLAUDE_PROJECT_DIR/.claude/helpers/ should work identically in worktrees and the main repo. Either:

1. Symlink .claude/helpers/ from the main repo into the worktree's .claude/ directory when creating the worktree, or
2. Set $CLAUDE_PROJECT_DIR to point to the original repo root (not the worktree) so hooks resolve against the canonical .claude/ directory, or
3. Provide a separate env var (e.g. $CLAUDE_MAIN_PROJECT_DIR) that always points to the original repo root for hook resolution

Workaround

Manually copy the helpers directory into the worktree:

mkdir -p <worktree>/.claude/helpers
cp <main-repo>/.claude/helpers/* <worktree>/.claude/helpers/

Environment

• Claude Code: latest (Claude Opus 4.6)
• Node.js: v22.22.0
• Platform: macOS (darwin arm64)