On a Linux host the UUP converter only produces the RTM install.wim (build
26100.1), so Windows Update had to install the entire cumulative anyway —
the UUP download/convert machinery added a slow ~5 GB step and several host
tools (aria2/wimtools/cabextract/chntpw) for no benefit.
Replace it: deploy-win now takes the install ISO directly via `--iso-url`
(urllib download + cache by file name under <CI_ROOT>/iso/, optional
--iso-sha256) or a local `--win-iso` (exactly one required). Patch + deploy
flow is unchanged. Supply an already-updated ISO (e.g. a massgrave link) to
skip the WU step entirely.
- Remove winimage/uup.py and its tests.
- Trim setup-host-linux.sh deps to p7zip-full + xorriso + genisoimage.
- Update RUNBOOK §5 and the Windows-host port plan. Coverage 93.6%.