fix: comprehensive script audit - bug fixes and optimizations

- ct/invidious.sh: fix copy-paste bug (OxiCloud code in update block)
- install/invidious-install.sh: fix sed redirect, service filename mismatch
- ct/forgejo-runner.sh: fix binary download path, bump Debian to 13
- ct/authentik.sh: add -f flag to curl (fail on HTTP errors)
- ct/localagi.sh: add -f flag to curl, add installation check guard
- ct/ente.sh: fix broken install check (/var -> /opt/ente), apt-get -> apt
- ct/garmin-grafana.sh: add explicit tarball mode to fetch_and_deploy
- install/garmin-grafana-install.sh: fix local outside function, add tarball mode
- install/ente-install.sh: uncomment cleanup_lxc
- install/github-runner-install.sh: add missing , fix msg_info text
- ct/step-ca.sh: remove duplicate success message
- ct/devuan.sh, ct/ubuntu.sh: apt-get -> apt, remove duplicate msg_ok

ct/ente.sh

@@ -24,13 +24,13 @@ function update_script() {
   header_info
   check_container_storage
   check_container_resources
-  if [[ ! -d /var ]]; then
+  if [[ ! -d /opt/ente ]]; then
     msg_error "No ${APP} Installation Found!"
     exit
   fi
   msg_info "Updating Ente LXC"
-  $STD apt-get update
-  $STD apt-get -y upgrade
+  $STD apt update
+  $STD apt -y upgrade
   msg_ok "Updated Ente LXC"
   exit
 }