Remove Content Pipeline system from the public repo

Removed by request - it was the one unfinished system in the repo,
and it's the user's call on what represents them publicly. Removed
completely: the README section, docs/content-pipeline.md, and the
two stacks that only existed to back it (postiz, nocodb-content).
Fixed cross-links in dns-naming.md and firewall-and-network.md that
pointed at it (replaced the public-facing-app example with the
still-present Ghost blog), and notifications.md (dropped the
reference, also fixed a leftover 'documented rather than hidden'
phrase in the same paragraph). Stat strip and stack counts updated
(55->53 stacks, 16->15 systems).

stacks/productivity/nocodb-content/docker-compose.yaml

@@ -1,41 +0,0 @@
-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

stacks/productivity/postiz/docker-compose.yaml

@@ -1,157 +0,0 @@
-services:
-  postiz:
-    image: ghcr.io/gitroomhq/postiz-app:latest
-    container_name: postiz
-    restart: unless-stopped
-    env_file:
-      - .env.secrets   # JWT_SECRET, DATABASE_URL, social-platform client IDs/secrets — never committed
-    environment:
-      TZ: ${TZ}
-      MAIN_URL: ${MAIN_URL}
-      FRONTEND_URL: ${FRONTEND_URL}
-      NEXT_PUBLIC_BACKEND_URL: ${NEXT_PUBLIC_BACKEND_URL}
-      BACKEND_INTERNAL_URL: ${BACKEND_INTERNAL_URL}
-      REDIS_URL: redis://postiz-redis:6379
-      TEMPORAL_ADDRESS: temporal:7233
-      IS_GENERAL: "true"
-      DISABLE_REGISTRATION: ${DISABLE_REGISTRATION}
-      STORAGE_PROVIDER: ${STORAGE_PROVIDER}
-      UPLOAD_DIRECTORY: ${UPLOAD_DIRECTORY}
-      NEXT_PUBLIC_UPLOAD_DIRECTORY: ${UPLOAD_DIRECTORY}
-      MASTODON_URL: ${MASTODON_URL}
-    volumes:
-      - /path/to/postiz/config:/config/
-      - /path/to/postiz/uploads:/uploads/
-    ports:
-      - "${HTTP_PORT}:5000"
-    depends_on:
-      postiz-postgres:
-        condition: service_healthy
-      postiz-redis:
-        condition: service_healthy
-    networks:
-      - postiz-net
-
-  postiz-postgres:
-    image: postgres:18-alpine
-    container_name: postiz-postgres
-    restart: unless-stopped
-    env_file:
-      - .env.secrets   # POSTGRES_PASSWORD — never committed
-    environment:
-      TZ: ${TZ}
-      POSTGRES_USER: ${POSTIZ_POSTGRES_USER}
-      POSTGRES_DB: ${POSTIZ_POSTGRES_DB}
-    volumes:
-      - /path/to/postiz/postgres_data:/var/lib/postgresql
-    healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U ${POSTIZ_POSTGRES_USER} -d ${POSTIZ_POSTGRES_DB}"]
-      interval: 10s
-      timeout: 3s
-      retries: 3
-    networks:
-      - postiz-net
-
-  postiz-redis:
-    image: valkey/valkey:9.0-alpine
-    container_name: postiz-redis
-    restart: unless-stopped
-    healthcheck:
-      test: ["CMD-SHELL", "valkey-cli ping"]
-      interval: 10s
-      timeout: 3s
-      retries: 3
-    volumes:
-      - /path/to/postiz/redis_data:/data
-    networks:
-      - postiz-net
-
-  # Temporal stack: required since Postiz v2.12.0 for all background jobs
-  # (scheduled posting, OAuth token refresh, email digests) — not optional,
-  # a real surprise in this app's actual deployment footprint.
-  temporal-elasticsearch:
-    image: elasticsearch:7.17.27
-    container_name: postiz-temporal-elasticsearch
-    restart: unless-stopped
-    environment:
-      - cluster.routing.allocation.disk.threshold_enabled=true
-      - cluster.routing.allocation.disk.watermark.low=512mb
-      - cluster.routing.allocation.disk.watermark.high=256mb
-      - cluster.routing.allocation.disk.watermark.flood_stage=128mb
-      - discovery.type=single-node
-      - ES_JAVA_OPTS=-Xms256m -Xmx256m
-      - xpack.security.enabled=false
-    volumes:
-      - /path/to/postiz/temporal_elasticsearch_data:/usr/share/elasticsearch/data
-    networks:
-      - postiz-net
-
-  temporal-postgres:
-    image: postgres:18-alpine
-    container_name: postiz-temporal-postgres
-    restart: unless-stopped
-    env_file:
-      - .env.secrets.temporal-postgres   # POSTGRES_PASSWORD — never committed; separate file, avoids a collision with postiz-postgres
-    environment:
-      TZ: ${TZ}
-      POSTGRES_USER: ${TEMPORAL_POSTGRES_USER}
-    volumes:
-      - /path/to/postiz/temporal_postgres_data:/var/lib/postgresql
-    networks:
-      - postiz-net
-
-  temporal:
-    image: temporalio/auto-setup:1.28.1
-    container_name: postiz-temporal
-    restart: unless-stopped
-    depends_on:
-      - temporal-postgres
-      - temporal-elasticsearch
-    env_file:
-      - .env.secrets   # POSTGRES_PWD — never committed
-    environment:
-      - DB=postgres12
-      - DB_PORT=5432
-      - POSTGRES_USER=${TEMPORAL_POSTGRES_USER}
-      - POSTGRES_SEEDS=temporal-postgres
-      - DYNAMIC_CONFIG_FILE_PATH=config/dynamicconfig/development-sql.yaml
-      - ENABLE_ES=true
-      - ES_SEEDS=temporal-elasticsearch
-      - ES_VERSION=v7
-      - TEMPORAL_NAMESPACE=default
-    ports:
-      - "127.0.0.1:${TEMPORAL_PORT}:7233"   # gRPC control plane, unauthenticated by default — localhost-only
-    volumes:
-      - ./dynamicconfig:/etc/temporal/config/dynamicconfig
-    networks:
-      - postiz-net
-
-  temporal-admin-tools:
-    image: temporalio/admin-tools:1.28.1-tctl-1.18.4-cli-1.4.1
-    container_name: postiz-temporal-admin-tools
-    restart: unless-stopped
-    environment:
-      - TEMPORAL_ADDRESS=temporal:7233
-      - TEMPORAL_CLI_ADDRESS=temporal:7233
-    depends_on:
-      - temporal
-    stdin_open: true
-    tty: true
-    networks:
-      - postiz-net
-
-  temporal-ui:
-    image: temporalio/ui:2.34.0
-    container_name: postiz-temporal-ui
-    restart: unless-stopped
-    environment:
-      - TEMPORAL_ADDRESS=temporal:7233
-      - TEMPORAL_CORS_ORIGINS=http://127.0.0.1:${TEMPORAL_UI_PORT}
-    ports:
-      - "127.0.0.1:${TEMPORAL_UI_PORT}:8080"   # unauthenticated by default — localhost-only, SSH-tunnel to debug
-    networks:
-      - postiz-net
-
-networks:
-  postiz-net:
-    external: true