Returns the dependency manager used in a directory.
Walks upward from fromDirectory so workspace packages (e.g. extensions/my-fn/package.json)
still resolve to the repo root lockfile (pnpm-lock.yaml).
If no lockfile is found, it falls back to the package manager from the user agent.
If the package manager from the user agent is unknown, it returns 'npm'.
Returns the dependency manager used in a directory. Walks upward from
fromDirectoryso workspace packages (e.g.extensions/my-fn/package.json) still resolve to the repo root lockfile (pnpm-lock.yaml). If no lockfile is found, it falls back to the package manager from the user agent. If the package manager from the user agent is unknown, it returns 'npm'.