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were entirely stale content describing a superseded architecture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/identity-and-security/authentik/docker-compose.yaml

@@ -0,0 +1,108 @@
+services:
+  postgresql:
+    env_file:
+      - .env
+    container_name: authentik-postgres
+    environment:
+      POSTGRES_DB: ${PG_DB}
+      POSTGRES_PASSWORD: ${PG_PASS}
+      POSTGRES_USER: ${PG_USER}
+    command: >
+      postgres
+      -c max_connections=400
+      -c shared_buffers=256MB
+      -c work_mem=8MB
+      -c maintenance_work_mem=128MB
+      -c effective_cache_size=1GB
+    healthcheck:
+      interval: 30s
+      retries: 5
+      start_period: 20s
+      test:
+        - CMD-SHELL
+        - pg_isready -d $${POSTGRES_DB} -U $${POSTGRES_USER}
+      timeout: 5s
+    image: docker.io/library/postgres:16-alpine
+    restart: unless-stopped
+    volumes:
+      - /path/to/authentik/database:/var/lib/postgresql/data
+    networks:
+      - authentik-net
+
+  redis:
+    image: redis:7-alpine
+    container_name: authentik-redis
+    restart: unless-stopped
+    command: redis-server --appendonly yes
+    healthcheck:
+      test: ["CMD", "redis-cli", "ping"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+    volumes:
+      - /path/to/authentik/redis:/data
+    networks:
+      - authentik-net
+
+  server:
+    command: server
+    container_name: authentik-server
+    depends_on:
+      postgresql:
+        condition: service_healthy
+      redis:
+        condition: service_healthy
+    env_file:
+      - .env
+    environment:
+      AUTHENTIK_POSTGRESQL__HOST: postgresql
+      AUTHENTIK_POSTGRESQL__NAME: ${PG_DB}
+      AUTHENTIK_POSTGRESQL__PASSWORD: ${PG_PASS}
+      AUTHENTIK_POSTGRESQL__USER: ${PG_USER}
+      AUTHENTIK_SECRET_KEY: ${AUTHENTIK_SECRET_KEY}
+      AUTHENTIK_REDIS__HOST: redis
+      AUTHENTIK_URL: ${AUTHENTIK_URL}
+    image: ${AUTHENTIK_IMAGE:-ghcr.io/goauthentik/server}:${AUTHENTIK_TAG:-2026.5.3}
+    ports:
+      - ${COMPOSE_PORT_HTTP}:9000
+    restart: unless-stopped
+    shm_size: 512mb
+    volumes:
+      - /path/to/authentik/data:/data
+      - /path/to/authentik/custom-templates:/templates
+    networks:
+      - authentik-net
+
+  worker:
+    command: worker
+    container_name: authentik-worker
+    depends_on:
+      postgresql:
+        condition: service_healthy
+      redis:
+        condition: service_healthy
+    env_file:
+      - .env
+    environment:
+      AUTHENTIK_POSTGRESQL__HOST: postgresql
+      AUTHENTIK_POSTGRESQL__NAME: ${PG_DB}
+      AUTHENTIK_POSTGRESQL__PASSWORD: ${PG_PASS}
+      AUTHENTIK_POSTGRESQL__USER: ${PG_USER}
+      AUTHENTIK_SECRET_KEY: ${AUTHENTIK_SECRET_KEY}
+      AUTHENTIK_REDIS__HOST: redis
+      AUTHENTIK_URL: ${AUTHENTIK_URL}
+    image: ${AUTHENTIK_IMAGE:-ghcr.io/goauthentik/server}:${AUTHENTIK_TAG:-2026.5.3}
+    restart: unless-stopped
+    shm_size: 512mb
+    user: root
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+      - /path/to/authentik/data:/data
+      - /path/to/authentik/certs:/certs
+      - /path/to/authentik/custom-templates:/templates
+    networks:
+      - authentik-net
+
+networks:
+  authentik-net:
+    external: true