feat(logout): wire injector to web-svc-logout and add robust CORS/CSP for /logout

- sys-front-inj-logout: depend on web-svc-logout (run-once guarded) and simplify task flow.
- web-svc-logout: align feature flags/formatting and extend CSP:
  - add cdn.jsdelivr.net to connect/script/style and quote values.
- Nginx: move CORS config into logout-proxy.conf.j2 with dynamic vars:
  - Access-Control-Allow-Origin set to canonical logout origin,
  - Allow-Credentials=true,
  - Allow-Methods=GET, OPTIONS,
  - basic headers list (Accept, Authorization),
  - cache disabled for /logout responses.
- Drop obsolete CORS var passing from 01_core.yml; headers now templated at proxy layer.

Prepares clean cross-origin logout orchestration from https://logout.veen.world.

Refs: ChatGPT discussion – https://chatgpt.com/share/68ebb75f-0170-800f-93c5-e5cb438b8ed4

roles/web-svc-logout/tasks/01_core.yml

@@ -21,11 +21,6 @@
 - name: "load docker, proxy for '{{ application_id }}'"
   include_role:
     name: sys-stk-full-stateless
-  vars:
-      aca_origin:       "'{{ domains | get_url('web-svc-logout', WEB_PROTOCOL) }}' always"
-      aca_credentials:  "'true' always"
-      aca_methods:      "'GET, OPTIONS' always"
-      aca_headers:      "'Accept, Authorization' always"
 
 - name: Create symbolic link from .env file to repository
   file: