Restructure compose mirror: stacks/ grouped by purpose, not by host

Replaces rocky-docker-lxc/, caddy-vm/, monitoring-vm/, and automation/
with a single stacks/ tree grouped by function (identity-and-security,
platform, media, productivity, dev-tools) - 55 stacks total, every one
a real directory in the private repos today.

Resolves all outstanding drift: adds Wazuh (previously entirely
missing), Firefly III and Postiz (never mirrored), the internal-zone
Caddy instance and the Cron Scheduler's separate NocoDB instance
(both previously conflated with their counterparts under one shared
folder); renames Calibre-Web to calibre-web-automated and splits
Kodi-MariaDB into kodi + mariadb-latest to match what the private
repos actually run now; drops the decommissioned NetBox stack.

Also removes automation/iac/old-content/ and
automation/ansible/old-playbooks/ in the same pass - both folders
were entirely stale content describing a superseded architecture
(GitLab instead of Gitea, HAProxy+mTLS SSO instead of the current
Caddy+Authentik setup), now replaced by docs/iac-pipeline.md.

stacks/productivity/nextcloud/docker-compose.yaml

@@ -0,0 +1,82 @@
+name: nextcloud
+services:
+  db:
+    image: lscr.io/linuxserver/mariadb:latest
+    container_name: nextcloud_db
+    volumes:
+      - /path/to/nextcloud/data/db:/var/lib/mysql
+      - /path/to/nextcloud/data/db-config:/config
+    environment:
+      - MYSQL_ROOT_PASSWORD=${MYSQL_ROOT_PASSWORD}
+      - MYSQL_DATABASE=${MYSQL_DATABASE}
+      - MYSQL_USER=${MYSQL_USER}
+      - MYSQL_PASSWORD=${MYSQL_PASSWORD}
+      - TZ=${TZ}
+    restart: unless-stopped
+    networks:
+      - nextcloud-net
+
+  redis:
+    image: redis:alpine
+    container_name: nextcloud_redis
+    environment:
+      - "TZ"
+    volumes:
+      - /path/to/nextcloud/data/redis:/data
+    restart: unless-stopped
+    networks:
+      - nextcloud-net
+
+  # Main Nextcloud container (custom image with SMB + cert trust)
+  nextcloud:
+    build:
+      context: ./nextcloud
+      dockerfile: Dockerfile
+    container_name: nextcloud
+    depends_on:
+      - db
+      - redis
+    volumes:
+      - /path/to/nextcloud/html:/var/www/html
+      - /path/to/nextcloud/html/data:/var/www/html/data
+      - /path/to/nextcloud/html/config:/var/www/html/config
+      - /path/to/nextcloud/html/custom_apps:/var/www/html/custom_apps
+      - /path/to/nextcloud/html/themes:/var/www/html/themes
+    env_file:
+      - ".env"
+    environment:
+      - "TZ"
+      - "DB_TYPE=mysql"
+      - "DB_HOST=db"
+      - "DB_NAME=${MYSQL_DATABASE}"
+      - "DB_USER=${MYSQL_USER}"
+      - "DB_PASSWORD=${MYSQL_PASSWORD}"
+    restart: unless-stopped
+    networks:
+      - nextcloud-net
+      - caddy-net
+
+  euro-office:
+    build:
+      context: ./euro-office
+      dockerfile: Dockerfile
+    container_name: nextcloud_euro-office
+    restart: unless-stopped
+    ports:
+      - "8080:80"
+    environment:
+      - JWT_ENABLED=true
+      - JWT_SECRET=${ONLYOFFICE_JWT_SECRET}
+    volumes:
+      - /path/to/nextcloud/euro-office/data:/var/lib/euro-office/documentserver
+      - /path/to/nextcloud/euro-office/logs:/var/log/euro-office/documentserver
+      - /path/to/nextcloud/euro-office/config:/etc/euro-office/documentserver
+    networks:
+      - nextcloud-net
+      - caddy-net
+
+networks:
+  nextcloud-net:
+    external: true
+  caddy-net:
+    external: true