feat(frontend): rename inj roles to sys-front-*, add sys-svc-cdn, cache-busting lookup

Introduce sys-svc-cdn (cdn_paths/cdn_urls/cdn_dirs) and ensure CDN directories + latest symlink.

Rename sys-srv-web-inj-* → sys-front-inj-*; update includes/templates; serve shared/per-app CSS & JS via CDN.

Add lookup_plugins/local_mtime_qs.py for mtime-based cache busting; split CSS into default.css/bootstrap.css + optional per-app style.css.

CSP: use style-src-elem; drop unsafe-inline for styles. Services: fix SYS_SERVICE_ALL_ENABLED bool and controlled flush.

BREAKING CHANGE: role names changed; replace includes and references accordingly.

Conversation: https://chatgpt.com/share/68b55494-9ec4-800f-b559-44707029141d

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

@@ -0,0 +1,19 @@
+# Base CDN root (shared across all roles)
+CDN_ROOT:     "{{ NGINX.DIRECTORIES.DATA.CDN }}"
+
+# Default version identifier: UTC timestamp
+CDN_VERSION:  "latest" # Latest is used atm because timestamp based would just lead to an unneccessary overhead
+
+# Base Url to deliver the files
+CDN_BASE_URL: "{{ domains | get_url('web-svc-cdn', WEB_PROTOCOL) }}"
+
+# Role specific CDN paths
+
+## Build CDN path structure (via filter)
+cdn:          "{{ CDN_ROOT | cdn_paths(application_id, CDN_VERSION) }}"
+
+## Flatten CDN dict to list of all string paths
+cdn_dirs:     "{{ cdn | cdn_dirs }}"
+
+# Dictionary with all urls
+cdn_urls:     "{{ cdn | cdn_urls(CDN_BASE_URL) }}"