feat(nextcloud): integrate Talk & Whiteboard; refactor to NEXTCLOUD_* vars; full-stack setup

config(ports): add Nextcloud websocket port (4003); canonical domains (nextcloud/talk/whiteboard)

refactor: unify get_app_conf usage & Jinja spacing; migrate paths/handlers to new NEXTCLOUD_* vars

feat(plugins): split plugin routines; configure Whiteboard via occ (URL + JWT)

fix(oidc): use NEXTCLOUD_URL for logout; correct LDAP attribute mappings; add OIDC flavor switch

feat: Whiteboard container & reverse-proxy location; Talk STUN/WS ports; Redis URL for Whiteboard

chore: drop obsolete TODO; minor cleanups in oauth2-proxy, matrix, peertube, pgadmin, phpldapadmin, pixelfed, phpmyadmin

security(schema): Bluesky jwt_secret now base64_prefixed_32; add Nextcloud whiteboard_jwt_secret

db: normalize postgres image tag templating; central DB host checks spacing fixes

ops: add full-stack bootstrap (certs, proxy, volumes); internal nginx config reload handler update

refs: https://chatgpt.com/share/68b5f5b7-8d64-800f-b001-1241f818dc0e

roles/web-app-nextcloud/tasks/04_admin.yml

@@ -0,0 +1,14 @@
+- name: Ensure Nextcloud administrator is in the 'admin' group
+  command: >
+    docker exec -u {{ NEXTCLOUD_DOCKER_USER }} {{ NEXTCLOUD_CONTAINER }}
+    php occ group:adduser admin {{ NEXTCLOUD_ADMINISTRATOR_USERNAME }}
+  register: add_admin_to_group
+  changed_when: "not ASYNC_ENABLED and 'Added user' in (add_admin_to_group.stdout | default(''))"
+  failed_when: >
+    not ASYNC_ENABLED and
+    (add_admin_to_group.rc != 0) and
+    ("is already a member of" not in (
+      (add_admin_to_group.stderr | default('')) ~ (add_admin_to_group.stdout | default(''))
+    ))
+  async: "{{ ASYNC_TIME if ASYNC_ENABLED | bool else omit }}"
+  poll:  "{{ ASYNC_POLL if ASYNC_ENABLED | bool else omit }}"