Add conditional restart support to service roles

Track config/image/systemd changes via register: directives and compute
a _restart_necessary variable for each service role, allowing the
systemd_service_manager to skip unnecessary restarts during install-* runs.

Covers 22 service roles: alertmanager-receiver, appservice-draupnir-for-all,
bridge-mautrix-wsproxy (+ syncproxy), cactus-comments, cactus-comments-client,
corporal, element-admin, ldap-registration-proxy, livekit-jwt-service, matrixto,
pantalaimon, prometheus-nginxlog-exporter, rageshake, registration, static-files,
sygnal, synapse-admin, synapse-auto-compressor, synapse-reverse-proxy-companion,
synapse-usage-exporter, and user-verification-service.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

roles/custom/matrix-pantalaimon/tasks/install.yml

@@ -25,6 +25,7 @@
     mode: 0644
     owner: "{{ matrix_user_name }}"
     group: "{{ matrix_group_name }}"
+  register: matrix_pantalaimon_config_result
 
 - name: Ensure pantalaimon container image is pulled
   community.docker.docker_image:
@@ -33,10 +34,10 @@
     force_source: "{{ matrix_pantalaimon_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
     force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_pantalaimon_docker_image_force_pull }}"
   when: "not matrix_pantalaimon_container_image_self_build | bool"
-  register: result
+  register: matrix_pantalaimon_container_image_pull_result
   retries: "{{ devture_playbook_help_container_retries_count }}"
   delay: "{{ devture_playbook_help_container_retries_delay }}"
-  until: result is not failed
+  until: matrix_pantalaimon_container_image_pull_result is not failed
 
 - name: Ensure pantalaimon repository is present on self-build
   ansible.builtin.git:
@@ -72,3 +73,13 @@
     src: "{{ role_path }}/templates/systemd/matrix-pantalaimon.service.j2"
     dest: "{{ devture_systemd_docker_base_systemd_path }}/matrix-pantalaimon.service"
     mode: 0644
+  register: matrix_pantalaimon_systemd_service_result
+
+- name: Determine whether Pantalaimon needs a restart
+  ansible.builtin.set_fact:
+    matrix_pantalaimon_restart_necessary: >-
+      {{
+        matrix_pantalaimon_config_result.changed | default(false)
+        or matrix_pantalaimon_systemd_service_result.changed | default(false)
+        or matrix_pantalaimon_container_image_pull_result.changed | default(false)
+      }}