Refactor SteamOS session management and launcher scripts

- Removed obsolete launch_desktop.sh and launch_session.sh scripts.
- Introduced new steam-launcher script to handle Steam launching and session tracking.
- Added steam-short-session-tracker for monitoring short Steam sessions and triggering repairs.
- Created steamos and steamos-session scripts for managing the SteamOS session.
- Implemented steamos-session-select for switching between Gamescope and Plasma sessions.
- Updated SDDM configuration for autologin and session management.
- Added new systemd services and targets for managing Gamescope and Steam sessions.
- Created desktop entries and icons for ALVR and SteamOS shortcuts.
- Enhanced logging and error handling across scripts.
- Cleaned up unused systemd slice and service files.
- Updated Ansible playbook to reflect new configurations and file structures.

ansible/files/game_station/systemd/user/gamescope-session.service

@@ -0,0 +1,17 @@
+[Unit]
+Description=Gamescope Session
+Before=graphical-session.target
+PartOf=graphical-session.target
+Wants=graphical-session-pre.target
+After=graphical-session-pre.target
+RefuseManualStart=yes
+
+[Service]
+TimeoutStartSec=5
+TimeoutStopSec=10
+ExecStart=gamescope-session
+Type=notify
+NotifyAccess=all
+# Make Steam's srt-logger write to the journal with it's own prefixes
+Environment=SRT_LOG_TO_JOURNAL=1
+Slice=session.slice