First Release

Add Windows portable build and rolling main release workflow

- Add PyInstaller launcher, spec, and Windows build script
- Add build requirements and release README for portable zip
- Document Windows zip build and rolling latest-main prerelease
- Add GitHub Actions workflow to update latest-main on main pushes
- Include GUI screenshots and expanded README guidance for actions/queues

ClickFlow latest main (81479bb)

Automated rolling build from the main branch.

Commit: 81479bb
Run: https://github.com/FelixClements/ClickFlow/actions/runs/29015976613

This prerelease is replaced on each push to main.