feat: Steamify's default setup for the new user during the install (Calamares step before cleanup)

steamify-prepare.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+# steamify-prepare.sh [steamify checkout]: puts the Steamify bundle on the
+# ISO (archiso/airootfs/usr/local/share/steamify/steamify.sh), used by the
+# installer's Steamify step. Built from a checkout when given, else the
+# newest release. Run before buildiso.sh.
+set -euo pipefail
+dest="$(cd "$(dirname "$0")" && pwd)/archiso/airootfs/usr/local/share/steamify/steamify.sh"
+mkdir -p "$(dirname "$dest")"
+if [[ -n "${1:-}" ]]; then
+    (cd "$1" && .github/tools/bundle.sh "$dest")
+else
+    curl -fsSL https://github.com/theupriser/steamify-cachyos/releases/latest/download/steamify.sh -o "$dest"
+fi
+grep -q -- '--defaults' "$dest" || { echo "This Steamify has no --defaults (needs 2.6.0 or newer)." >&2; exit 1; }
+chmod 755 "$dest"
+echo "Steamify $(grep -m1 '^VERSION=' "$dest" | cut -d= -f2) on the ISO."