Refactor run-once logic across multiple roles and integrate unified utils/run_once.yml

This commit standardizes all run-once implementations across the following roles:
- desk-git
- dev-fakeroot
- dev-git
- dev-python-yaml
- sys-lock
- sys-svc-certs (wildcard flavor)
- update-apt
- update-pacman
- update-compose
- user-root (moved logic to 01_core.yml + unified run-once handling)
- web-app-matomo
- web-svc-libretranslate

All roles now:
- Use a block guarded by 'run_once_<role>' facts
- Trigger run-once state through utils/run_once.yml
- Optionally disable handler flushing via 'flush_handlers: false'
- Achieve consistent per-host one-time execution semantics

Conversation reference: https://chatgpt.com/share/692c7fbb-ff68-800f-8cb4-4b132cffc8e4

roles/sys-lock/tasks/main.yml

@@ -1,11 +1,11 @@
 ---
-- name: create {{ PATH_SYSTEM_LOCK_SCRIPT }}
-  copy:
-    src: sys-lock.py
-    dest: "{{ PATH_SYSTEM_LOCK_SCRIPT }}"
-  when: run_once_sys_lock is not defined
+- block:
+    - name: create {{ PATH_SYSTEM_LOCK_SCRIPT }}
+      copy:
+        src: sys-lock.py
+        dest: "{{ PATH_SYSTEM_LOCK_SCRIPT }}"
 
-- name: execute the script copying once
-  set_fact:
-    run_once_sys_lock: true
+    - include_tasks: utils/run_once.yml
+      vars:
+        flush_handlers: false
   when: run_once_sys_lock is not defined