api: is_supported_system add check for init package

`init` is a metapackage ensuring the init system is installed on any debian based system. if this package cannot be found in the local apt cache, then the user is missing the default debian sources

api

@@ -2560,6 +2560,10 @@ Specifically, the issue is $(wc -l <<<"$frankendebian" | grep -q 1 && echo 'this
     done
     echo "Your system might be recoverable if you did this recently and have not performed an apt upgrade yet, but otherwise you should probably reinstall your OS."
     return 1
+  elif ! package_available init; then
+    echo "Congratulations, Linux tinkerer, you broke your system. The init package can not be found, which means you have removed the default debian sources from your system.
+All apt based application installs will fail. Unless you have a backup of your /etc/apt/sources.list /etc/apt/sources.list.d you will need to reinstall your OS."
+    return 1
   elif [ -z "$(apt-get indextargets --no-release-info --format '$(SITE) $(RELEASE)' | sort -u | awk 'NF==2 {print}')" ];then
     echo "Congratulations, Linux tinkerer, you broke your system. You have removed ALL debian sources from your system.
 All apt based application installs will fail. Unless you have a backup of your /etc/apt/sources.list /etc/apt/sources.list.d you will need to reinstall your OS."