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were entirely stale content describing a superseded architecture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

@@ -0,0 +1,41 @@
+services:
+  nocodb:
+    image: nocodb/nocodb:latest
+    container_name: nocodb-content
+    restart: unless-stopped
+    ports:
+      - "${HTTP_PORT}:8080"
+    depends_on:
+      nocodb_db:
+        condition: service_healthy
+    env_file:
+      - .env.secrets   # NC_DB, NC_AUTH_JWT_SECRET — never committed
+    volumes:
+      - /path/to/nocodb-content/nc_data:/usr/app/data
+    networks:
+      - nocodb-content-net
+
+  nocodb_db:
+    image: postgres:18-alpine
+    container_name: nocodb-content-postgres
+    restart: unless-stopped
+    env_file:
+      - .env.secrets   # POSTGRES_PASSWORD — never committed
+    environment:
+      TZ: ${TZ}
+      POSTGRES_DB: ${POSTGRES_DB}
+      POSTGRES_USER: ${POSTGRES_USER}
+    volumes:
+      - /path/to/nocodb-content/db_data:/var/lib/postgresql
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER} -d ${POSTGRES_DB}"]
+      interval: 10s
+      timeout: 5s
+      retries: 10
+      start_period: 20s
+    networks:
+      - nocodb-content-net
+
+networks:
+  nocodb-content-net:
+    external: true