Standardized package installation commands to use 'apt install' instead of 'apt-get'. Replaced manual database setup with helper functions for PostgreSQL and MariaDB where applicable. Hardware acceleration setup is now handled by a shared function. Removed repetitive cleanup code and replaced with a single 'cleanup_lxc' call at the end of each script. Updated PHP version for FreshRSS and simplified repository setup for Fhem and Grafana. Fixed merge conflict in graylog-install.sh and removed unnecessary temporary file handling.