Install and first-run fixes, found by downloading a release onto a second
machine and watching it fail:
  * a machine with no OpenGL 3.3 (VM, RDP, missing driver) now names the cause,
    points at the web UI, and KEEPS THE SERVER RUNNING instead of exiting
    silently with nothing on screen
  * Windows ships the .zip the download table has always promised (the build
    only made one when `zip` was installed, and it isn't on the build machine)
  * veil.exe / veil-desk.exe carry the veil mark as their file icon at every
    shell size, so Explorer, shortcuts and pinned entries stop showing the
    generic glyph

See docs/release/RELEASE-v1.0.0-alpha.10.md.