Refactor systemctl services and categories due to alarm bugs

This commit restructures systemctl service definitions and category mappings.

Motivation: Alarm-related bugs revealed inconsistencies in service and role handling.

Preparation step: lays the groundwork for fixing the alarm issues by aligning categories, roles, and service templates.

roles/sys-svc-directory-validator/README.md

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+# Backup Directory Validator
+
+## Description
+
+This Ansible role installs the [directory-validator](https://github.com/kevinveenbirkenbach/directory-validator.git). It is used by the sys-ctl-bkp-docker-2-loc and sys-ctl-cln-faild-bkps roles to verify whether backups have been successfully created.
+
+## Overview
+
+The role retrieves the latest version of the directory-validator from its Git repository and installs it into the designated folder (configured via the `backup_directory_validator_folder` variable). A fact is set to ensure that the repository is pulled only once per playbook run.
+
+## Purpose
+
+The primary purpose of this role is to validate backup directories. By fetching the directory-validator tool, it enables dependent roles to assess the integrity and success of backup operations.
+
+## Features
+
+- **Git Repository Pull:** Automatically pulls the latest version of the directory-validator from Git.
+- **Idempotent Execution:** Ensures that the repository is fetched only once per playbook run.
+- **Backup Verification:** Serves as a validation step for other sys-bkp-related roles.
+- **Configurable Destination:** The target folder is customizable via the `backup_directory_validator_folder` variable.