v0.2.0-alpha

Install vellum-wm onto the target — installed systems had no WM

The engine copied the vellum CLI into the new system but never
vellum-wm, so xinitrc's 'exec vellum-wm' had nothing to run and an
installed machine couldn't reach the desktop. Copy the media-embedded
/usr/local/bin/vellum-wm when present, embed WM_BIN on the memstick
too (shared inject_vellum), and pass it in CI.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>