* feat: add `pnpm clean` command for safe node_modules removal
Adds a new `pnpm clean` command that safely removes node_modules contents
from all workspace projects. Uses Node.js fs.rm() which correctly handles
NTFS junctions on Windows without following them into their targets,
preventing catastrophic data loss. Preserves non-pnpm hidden files
(e.g. .cache) and lockfiles by default; use --lockfile/-l to also
remove pnpm-lock.yaml files. Also cleans custom virtual-store-dir
when configured inside the project root.
Closes#10707
* fix: use is-subdir package instead of custom implementation, check existence before printing
- Replace custom isSubdir function with the existing is-subdir package
- Only print "Removing" and remove lockfile/virtualStoreDir when they exist
- Rethrow non-ENOENT errors instead of swallowing them
* refactor: use path-exists package, handle TOCTOU race in removeModulesDirContents
- Replace manual fs.access + try/catch with pathExists for cleaner existence checks
- Add ENOENT handling to removeModulesDirContents readdir to handle the race
where the directory is removed between hasContentsToRemove and readdir
* refactor: use opts object with .bind for cleanProjectDir, rename to removeLockfile
