feat: Add scripts and systemd services for SteamOS session management and game launching

ansible/files/game_station/bin/system/launch_desktop.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+set -euo pipefail
+LOGFILE="$HOME/.local/logs/desktop.log"
+
+log() { echo "[$(date --iso-8601=seconds)] $*" | tee -a "$LOGFILE"; }
+
+log "Starting Desktop session..."
+
+DESKTOP_SESSION_BIN="$(command -v startplasma-wayland || true)"
+if [ -z "$DESKTOP_SESSION_BIN" ]; then
+  log "ERROR: startplasma-wayland not found in PATH"
+  exit 127
+fi
+
+log "Launching Desktop: $DESKTOP_SESSION_BIN"
+exec "$DESKTOP_SESSION_BIN" >>"$LOGFILE" 2>&1 &
+
+sleep 5
+systemd-run --user --slice=sunshine.slice --scope sunshine >>"$LOGFILE" 2>&1 || {
+  log "ERROR: Failed to start Sunshine"
+  exit 1
+} &
+
+tail -f /dev/null