fix: Add CachyOS test VM dev environment and VM testing skill

QEMU/KVM scripts for a CachyOS KDE test VM (run.sh/run.ps1, get-iso,
guest SSH setup), host helper scripts to drive and inspect the
cachyos-gamescope-boot wizard in the guest, and a Claude Code skill
documenting the test workflow.

scripts/vmrun.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+# Run the wizard inside the guest's Plasma session with scripted menu input.
+#   scripts/vmrun.sh '<menu input>'      e.g. scripts/vmrun.sh '\ny\nn\n'
+# Input is interpreted by printf: numbers toggle, empty line continues,
+# a = re-apply, q = quit; then y for "Go ahead?" and n for the restart question.
+# Env: VM_USER (theupriser), VM_PORT (2222), VM_HOST (localhost),
+#      GUEST_REPO (/mnt, where the repo is mounted in the guest), GUEST_UID (1000).
+set -euo pipefail
+. "$(dirname "$0")/common.sh"
+input="${1:?usage: $0 '<menu input>'}"
+GUEST_REPO="${GUEST_REPO:-/mnt}"
+GUEST_UID="${GUEST_UID:-1000}"
+# The guest login shell is fish, so pass values in through the bash script itself.
+{ printf 'input=%q repo=%q uid=%q\n' "$input" "$GUEST_REPO" "$GUEST_UID"; cat << 'REMOTE'
+export XDG_RUNTIME_DIR=/run/user/$uid WAYLAND_DISPLAY=wayland-0 DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$uid/bus
+log=/tmp/wizard.log
+# shellcheck disable=SC2059
+printf "$input" | "$repo/setup-gamescope-boot.sh" > "$log" 2>&1; echo "exit=$?" >> "$log"
+cat "$log"
+REMOTE
+} | vm_ssh bash -s 2>&1 | sed 's/\x1b\[[0-9;]*m//g'