feat: Refactor game station launch scripts and update session management

ansible/files/game_station/system/steamos-session-select

@@ -0,0 +1,27 @@
+#!/bin/bash
+set -euo pipefail
+LOGFILE="$HOME/.local/logs/session.log"
+
+log() { echo "[$(date --iso-8601=seconds)] $*" | tee -a "$LOGFILE"; }
+
+session="${1:-gamescope}"
+
+case "$session" in
+  plasma*)
+    log "Plasma session selected."
+    touch "$HOME/.desktop-session-plasma"
+  ;;
+  gamescope)
+    log "Gamescope session selected."
+    if [[ -f "$HOME/.desktop-session-plasma" ]]; then
+      rm "$HOME/.desktop-session-plasma"
+    fi
+  ;;
+  *)
+    log "!! Unrecognized session '$session'"
+    exit 1
+  ;;
+esac
+
+log "Restarting graphical session service..."
+sudo systemctl restart gamescope-session.service