Refactor role naming for TLS and proxy stack

- Renamed role `srv-tls-core` → `sys-svc-certs`
- Renamed role `srv-https-stack` → `sys-stk-front-pure`
- Renamed role `sys-stk-front` → `sys-stk-front-proxy`
- Updated all includes, READMEs, meta, and dependent roles accordingly

This improves clarity and consistency of naming conventions for certificate management and proxy orchestration.

See: https://chatgpt.com/share/68b19f2c-22b0-800f-ba9b-3f2c8fd427b0

roles/sys-stk-full-stateful/tasks/main.yml

@@ -4,9 +4,9 @@
   vars:
     handler_role_name: "svc-prx-openresty"
 
-- name: "For '{{ application_id }}': include role sys-stk-front"
+- name: "For '{{ application_id }}': include role sys-stk-front-proxy"
   include_role:
-    name: sys-stk-front
+    name: sys-stk-front-proxy
   vars:
     domain:     "{{ domains | get_domain(application_id) }}"
     http_port:  "{{ ports.localhost.http[application_id] }}"