Add an optional desktop app launcher

[KingAkeem]

What changed

This keeps TorBot CLI-first, but gives people a simple way to open the separate TorBotApp desktop UI when they have it installed locally. The app stays optional, so we are not pulling Node or Electron into the Python package.

The installed torbot command now supports both torbot app and torbot --app, with discovery through --app-dir, TORBOT_APP_DIR, or a sibling TorBotApp checkout.

I also moved the CLI implementation into the package so the console entry point works from an installed wheel, bumped the version to 4.2.0, removed the deprecated sklearn dependency, and made the publish script safer around current-version artifacts and PyPI tokens.

Checks

• .venv/bin/python -m pytest
• .venv/bin/python -m flake8 main.py src/torbot/cli.py src/torbot/modules/app_launcher.py tests/test_cli_and_crawler.py
• scripts/publish.sh
• Installed the built torbot-4.2.0 wheel in a fresh temp venv and checked torbot --version plus the app-launch guidance path