Refactor alarm composer and sys-service handling:

- Introduce dynamic SYSTEMCTL_ALARM_COMPOSER_SUBSERVICES based on Mailu token and MODE_RESET
- Prevent inclusion of sys-ctl-alm-email when disabled
- Add system_service_is_template flag to avoid state-setting on template services
- Update notifications to reload daemon for @ template units
- Align msmtp execution conditions

See: https://chatgpt.com/share/692c7a71-afcc-800f-8aba-6800a042ce3b

roles/sys-service/vars/main.yml

@@ -1,5 +1,8 @@
 UNIT_SUFFIX_REMOVER_PACKAGE:          "unsure"
+
+# meta
 system_service_name:                  "{{ system_service_id | get_service_name(SOFTWARE_NAME) }}"
+system_service_is_template:           "{{ system_service_id.endswith('@') }}"
 
 ## Paths
 system_service_role_name:             "{{ system_service_id | regex_replace('@','') }}"