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were entirely stale content describing a superseded architecture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/media/immich/docker-compose.yaml

@@ -0,0 +1,75 @@
+services:
+  immich-server:
+    container_name: immich_server
+    environment:
+      - PUID=${PUID}
+      - PGID=${PGID}
+      - TZ=${TZ}
+    image: ghcr.io/immich-app/immich-server:${IMMICH_VERSION:-release}
+    volumes:
+      - /path/to/immich/data:/data
+      - /path/to/immich/upload:/usr/src/app/upload
+      - /path/to/external-library-1:/path/to/external-library-1:ro
+      - /path/to/external-library-2:/path/to/external-library-2:ro
+    env_file:
+      - .env
+    ports:
+      - ${HTTP_PORT}:2283
+    depends_on:
+      - redis
+      - database
+    restart: unless-stopped
+    networks:
+      - immich-net
+
+  immich-machine-learning:
+    container_name: immich_machine_learning
+    environment:
+      - PUID=${PUID}
+      - PGID=${PGID}
+      - TZ=${TZ}
+    image: ghcr.io/immich-app/immich-machine-learning:${IMMICH_VERSION:-release}
+    volumes:
+      - /path/to/immich/model-cache:/cache
+    env_file:
+      - .env
+    restart: unless-stopped
+    networks:
+      - immich-net
+
+  redis:
+    container_name: immich_redis
+    image: redis:6.2-alpine
+    environment:
+      - PUID=${PUID}
+      - PGID=${PGID}
+      - TZ=${TZ}
+    volumes:
+      - /path/to/immich/redis:/data
+    restart: unless-stopped
+    networks:
+      - immich-net
+
+  database:
+    container_name: immich_postgres
+    image: ghcr.io/immich-app/postgres:14-vectorchord0.4.3-pgvectors0.2.0
+    env_file:
+      - .env
+    environment:
+      - PUID=${PUID}
+      - PGID=${PGID}
+      - TZ=${TZ}
+      - POSTGRES_PASSWORD=${DB_PASSWORD}
+      - POSTGRES_USER=${DB_USERNAME}
+      - POSTGRES_DB=${DB_DATABASE_NAME}
+      - POSTGRES_INITDB_ARGS='--data-checksums'
+    volumes:
+      - /path/to/immich/pgdata:/var/lib/postgresql/data
+    shm_size: 128mb
+    restart: unless-stopped
+    networks:
+      - immich-net
+
+networks:
+  immich-net:
+    external: true