refactor!: replace sys-systemctl with sys-service, add sys-daemon, and rename systemctl_* → system_service_* across repo

- Swap role includes: sys-systemctl → sys-service in all roles
- Rename variables everywhere: systemctl_* → system_service_* (incl. systemctl_id → system_service_id)
- Templates: ExecStart now uses {{ system_service_script_exec }}; add optional RuntimeMaxSec via SYS_SERVICE_DEFAULT_RUNTIME
- Move SYS_SERVICE defaults into roles/sys-service/defaults (remove SYS_SERVICE_ALL_ENABLED & SYS_SERVICE_DEFAULT_STATE from group_vars/07_services.yml)
- Tidy group_vars/all/08_timer.yml formatting
- Introduce roles/sys-daemon:
  - default manager timeouts (timeouts.conf)
  - optional purge of /etc/systemd/system.conf.d
  - validation via systemd-analyze verify
  - handlers for daemon-reload & daemon-reexec
- Refactor sys-timer to system_service_* variables (docs and templates updated)
- Move filter_plugins/filetype.py under sys-service
- Update meta/README to point to official systemd docs
- Touch many roles (backup/cleanup/health/repair/certs/nginx/csp/wireguard/ssd-hdd/keyboard/update-docker/alarm compose/email/telegram/etc.) to new naming

BREAKING CHANGE:
- Role path/name change: use `sys-service` instead of `sys-systemctl`
- All `systemctl_*` vars are now `system_service_*` (e.g., on_calendar, state, timer_enabled, script_exec, id)
- If you have custom templates, adopt RuntimeMaxSec and new variable names

Chat context: https://chatgpt.com/share/68a47568-312c-800f-af3f-e98575446327

roles/sys-daemon/tasks/02_defaults.yml

@@ -0,0 +1,12 @@
+- name: "Ensure {{ SYSTEMD_MANAGER_CONF_DIR }} exists"
+  file:
+    path: "{{ SYSTEMD_MANAGER_CONF_DIR }}"
+    state: directory
+    mode: "0755"
+
+- name: Deploy systemd manager default timeout settings
+  template:
+    src:  timeouts.conf.j2
+    dest: "{{ SYSTEMD_MANAGER_CONF_DIR }}/timeouts.conf"
+    mode: "0644"
+  notify: reexec systemd manager