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/steam.slice

@@ -1,3 +1,15 @@
+#  SPDX-License-Identifier: LGPL-2.1-or-later
+#
+#  This file is part of systemd.
+#
+#  systemd is free software; you can redistribute it and/or modify it
+#  under the terms of the GNU Lesser General Public License as published by
+#  the Free Software Foundation; either version 2.1 of the License, or
+#  (at your option) any later version.
+
+[Unit]
+Description=User Core Session Slice
+Documentation=man:systemd.special(7)
+
 [Slice]
-CPUWeight=100
-AllowedCPUs={{ general_cores }}
+CPUWeight=100