Improve CLI safety and package consistency

[FnrDev]

Summary

• align the package name, executable, and README around rm-node-m while retaining del_nodem as a compatibility alias
• support an optional target directory and continue scanning after read or removal failures
• report deletion/failure totals and return a failing exit status when any operation fails
• mark the CLI executable and add integration coverage for deletion, defaults, empty scans, and error handling

Testing

• npm test
• npm pack --dry-run

[FnrDev]

@omarakamal A bit of improvements 😆