refactor(webserver): rename roles and update references

- Rename sys-svc-webserver -> sys-svc-webserver-core
- Rename sys-stk-front-pure -> sys-svc-webserver-https
- Update includes, run_once flags, and docs across:
  * sys-ctl-mtn-cert-renew
  * sys-front-inj-*
  * sys-stk-front-proxy
  * sys-svc-certs
  * sys-svc-cln-domains
  * web-opt-rdr-*
  * web-svc-*
- Remove redundant webserver include in web-opt-rdr-www
- Fix documentation links

Ref: ChatGPT conversation https://chatgpt.com/share/68d6cea2-3570-800f-acb3-c3277317f17b

roles/sys-svc-webserver-core/tasks/02_cleanup.yml

@@ -0,0 +1,8 @@
+- name: Cleanup all NGINX cache directories
+  become: true
+  ansible.builtin.file:
+    path: "{{ item.value }}"
+    state: absent
+  loop: "{{ NGINX.DIRECTORIES.CACHE | dict2items }}"
+  loop_control:
+    label: "{{ item.key }}"