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-user-verification-service/defaults/main.yml

@@ -85,3 +85,13 @@ matrix_user_verification_service_uvs_openid_verify_server_name: "{{ matrix_domai
 # Log level
 # See choices here: https://github.com/winstonjs/winston#logging-levels
 matrix_user_verification_service_uvs_log_level: info
+
+# matrix_user_verification_service_restart_necessary controls whether the service
+# will be restarted (when true) or merely started (when false) by the
+# systemd service manager role (when conditional restart is enabled).
+#
+# This value is automatically computed during installation based on whether
+# any configuration files, the systemd service file, or the container image changed.
+# The default of `false` means "no restart needed" — appropriate when the role's
+# installation tasks haven't run (e.g., due to --tags skipping them).
+matrix_user_verification_service_restart_necessary: false

roles/custom/matrix-user-verification-service/tasks/setup_install.yml

@@ -24,10 +24,10 @@
     source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
     force_source: "{{ matrix_user_verification_service_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_user_verification_service_docker_image_force_pull }}"
-  register: result
+  register: matrix_user_verification_service_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_user_verification_service_container_image_pull_result is not failed
   when: "not matrix_user_verification_service_container_image_self_build | bool"
 
 - name: Ensure Matrix User Verification Service repository is present when self-building
@@ -60,6 +60,7 @@
     owner: "{{ matrix_user_name }}"
     group: "{{ matrix_group_name }}"
     mode: 0644
+  register: matrix_user_verification_service_config_result
 
 - name: Ensure matrix-user-verification-service container network is created
   community.general.docker_network:
@@ -73,3 +74,13 @@
     src: "{{ role_path }}/templates/systemd/matrix-user-verification-service.service.j2"
     dest: "{{ devture_systemd_docker_base_systemd_path }}/{{ matrix_user_verification_service_systemd_service_name }}"
     mode: 0644
+  register: matrix_user_verification_service_systemd_service_result
+
+- name: Determine whether Matrix User Verification Service needs a restart
+  ansible.builtin.set_fact:
+    matrix_user_verification_service_restart_necessary: >-
+      {{
+        matrix_user_verification_service_config_result.changed | default(false)
+        or matrix_user_verification_service_systemd_service_result.changed | default(false)
+        or matrix_user_verification_service_container_image_pull_result.changed | default(false)
+      }}