refactor(front-injection): stabilize run_once flow and explicit web-service loading

- sys-front-inj-all: load web-svc-cdn and web-svc-logout once; reinitialize inj_enabled after services; move run_once block to top; reorder injections.
- sys-front-inj-css: move run_once call into 01_core; fix app_style_present default; simplify main.
- sys-front-inj-desktop/js/matomo: deactivate per-role run_once blocks; keep utils/run_once where appropriate.
- sys-front-inj-logout: switch to files/logout.js + copy; update head_sub mtime lookup; mark set_fact tasks unchanged.
- sys-svc-cdn: inline former 01_core tasks into main; ensure shared/vendor dirs and set run_once in guarded block; remove 01_core.yml.

Rationale: prevent cascading 'false_condition: run_once_sys_svc_cdn is not defined' skips by setting run-once facts only after the necessary tasks and avoiding parent-scope guards; improves determinism and handler flushing.

Conversation: https://chatgpt.com/share/68ecfaa5-94a0-800f-b1b6-2b969074651f

roles/sys-svc-cdn/tasks/main.yml

@@ -1,6 +1,14 @@
 ---
 - block:
-    - include_tasks: 01_core.yml
+    - name: Ensure shared root and vendor exist (run once)
+      ansible.builtin.file:
+        path:  "{{ item }}"
+        state: directory
+        owner: "{{ NGINX.USER }}"
+        group: "{{ NGINX.USER }}"
+        mode:  "0755"
+      loop: "{{ CDN_DIRS_GLOBAL }}"
+    - include_tasks: utils/run_once.yml
   when:
     - run_once_sys_svc_cdn is not defined