Add `ci template check-win-iso`: parse the massgrave windows-server-links
markdown source on GitHub for the newest Windows Server 2025 build, file
name and link, and report whether it is already in <CI_ROOT>/iso/. The
download itself stays manual — the massgrave link is behind a Cloudflare
Turnstile file host, not scriptable.
Add `ci template patch-win-iso --in ISO [--out ISO]`: standalone equivalent
of deploy-win Step 4 — inject autounattend.xml + post-install.ps1 and a
no-prompt boot image into a manually downloaded ISO, producing a
ready-to-deploy `.patched.iso`.
winimage/massgrave.py does the parse (no auto-download). RUNBOOK §5
documents the check → download → patch → deploy workflow. Coverage 93.6%.