tools: Centralize GPU group setup via setup_hwaccel (#13044)

improve hardware-acceleration setup to centralize service user group management. Install scripts (emby, plex, ollama, channels) now pass a service user to setup_hwaccel (or no user for channels) and have had inline /etc/group sed/usermod tweaks removed. misc/tools.func updated: setup_hwaccel accepts an optional service_user and forwards it to _setup_gpu_permissions, which now adds the service user to render and video groups if provided. This consolidates GPU permission changes in one place and removes duplicated per-service group edits.

install/plex-install.sh

@@ -13,7 +13,7 @@ setting_up_container
 network_check
 update_os
 
-setup_hwaccel
+setup_hwaccel "plex"
 
 msg_info "Setting Up Plex Media Server Repository"
 setup_deb822_repo \
@@ -26,11 +26,6 @@ msg_ok "Set Up Plex Media Server Repository"
 
 msg_info "Installing Plex Media Server"
 $STD apt install -y plexmediaserver
-if [[ "$CTTYPE" == "0" ]]; then
-  sed -i -e 's/^ssl-cert:x:104:plex$/render:x:104:root,plex/' -e 's/^render:x:108:root$/ssl-cert:x:108:plex/' /etc/group
-else
-  sed -i -e 's/^ssl-cert:x:104:plex$/render:x:104:plex/' -e 's/^render:x:108:$/ssl-cert:x:108:/' /etc/group
-fi
 msg_ok "Installed Plex Media Server"
 
 motd_ssh