Refactor Nextcloud fullstack and config tasks:

- Load proxy in fullstack
- Simplify config merging logic
- Improve handler flushing and container config update

Context: https://chatgpt.com/share/692dc9d4-a884-800f-85e5-e92471c7b52b

roles/web-app-nextcloud/tasks/01_fullstack.yml

@@ -1,4 +1,4 @@
-- name: "load docker and db for {{ application_id }}"
+- name: "load docker, db and proxy for {{ application_id }}"
   include_role:
     name: sys-stk-full-stateful
   vars:

roles/web-app-nextcloud/tasks/02_config.yml

@@ -1,5 +1,5 @@
-- name: Merge all files in infinito directory (container)
-  block:
+# Merge all (config) files in infinito directory (container)
+
 - name: Add dynamic config merging from Jinja template
   template:
     src: include.php.j2

roles/web-app-nextcloud/tasks/main.yml

@@ -1,9 +1,4 @@
 ---
-- name: "load docker, db and proxy for {{ application_id }}"
-  include_role:
-    name: sys-stk-full-stateful
-  vars:
-
 - name: Setup the full docker stack
   include_tasks: 01_fullstack.yml
   vars: