v4.27.0 — worktree runners mirror every node_modules dir from the repo top

Fixed

• Worktree runners now mirror every node_modules dir of the source checkout, resolved
  from the repo top (issue #158). Each *-worktree-run.sh used to create one link,
  $REPO/node_modules → $WT/node_modules, with $REPO being whatever --cwd was. On an npm
  workspaces monorepo with --cwd <repo>/packages/core, git worktree add still checks out the
  whole repo, so the worktree ROOT received the package-local node_modules and the hoisted
  root install (node_modules/.bin/vitest) was never linked — the worker finished fine and
  --verify 'cd packages/core && npx vitest run …' died with sh: vitest: command not found
  (exit 127). The runners now list the source's ignored node_modules/ directories from
  git rev-parse --show-toplevel (git ls-files --others --ignored --exclude-standard --directory, ~17 ms on a six-package monorepo) and symlink each into the worktree at the same
  relative path — root and per-package alike — skipping anything that already exists there.
  Cleanup removes all such links (find "$WT" -name node_modules -type l -delete; the printed
  manual-cleanup hint says the same); git worktree remove --force was verified not to follow
  the links into the source install. Regression test: worktree-node-modules.test.mjs (all
  five runners; --cwd at a package, at the root, and with no node_modules at all).