docs: wsl-build-host skill, vminstall.sh without udisks (WSL), AGENTS.md/TODO WSL notes corrected

The WSL box has a desktop after all (WSLg windows on Windows), closing the
Arch window shuts it down, and vminstall.sh loop-mounts the ISO with losetup
as root when udisksctl is missing (R1c).

TODO.md

@@ -66,10 +66,10 @@ Where the time goes: boot loader VMs ~3 min each, every suite block restores a s
 - [ ] R1b. The PC is WSL2 (Windows). To check there: `/dev/kvm` exists (Windows 11, virtualization on in the BIOS,
       nested virtualization on); `%UserProfile%\.wslconfig` `memory=` is raised (WSL2 defaults to half the RAM = 32 GB;
       3-4 VMs at 4-8 GB want ~48 GB) and `processors=16`; keep `~/vms` and the repos on WSL's own ext4, not under `/mnt/c`;
-      `sudo apt install qemu-system-x86 ovmf screen`; no desktop there, so runs are headless with no Konsole (`view_start`
-      returns early; watch with `screen -r vmtest` or `tail -f ~/vms/test.log`)
-- [ ] R1c. `vminstall.sh` reads the ISO's kernel with `udisksctl`, which WSL doesn't have: use `bsdtar`/`7z` when there is no
-      udisks (same as CI step 2), or copy the VM directories (`~/vms/steamify-vm`, `bl-*`, ~35 GB) from the laptop with rsync
+      the distro is Arch (root): `pacman -S qemu-full edk2-ovmf screen`; automated runs are headless with no Konsole
+      (`view_start` returns early; watch with `screen -r vmtest` or `tail -f ~/vms/test.log`), a VM for the user gets a
+      window through WSLg (see the wsl-build-host skill). Still to do: a first full `vmtest.sh` run there
+- [x] R1c. `vminstall.sh` without udisks (WSL): `losetup -P` + `mount` when `udisksctl` is missing and it runs as root
 - [ ] R2. With 64 GB and 8c/16t: try `MAX_PARALLEL=4` and 8 GB VMs (`VM_MEM=8G`)
 
 ## Boot loader test (local)