feat: add Atuin shell history synchronization service

- Add Atuin v18.10.0 service with PostgreSQL 14 database backend
- Configure Atuin server on port 4018 with open registration for demo
- Add PostgreSQL database service with proper health checks
- Update demo-stack.sh status display to include Atuin URL
- Update README.md service table with Atuin entry
- Add Atuin configuration variables to demo.env
- Use TCP socket health check for Atuin (no curl available in container)
- Atuin server accessible and responding with version info
- All services including Atuin now operational and healthy

SupportStack/demo/docker-compose.yml.template

@@ -309,6 +309,64 @@ services:
       homepage.href: "http://192.168.3.6:${MAILHOG_WEB_PORT}"
       homepage.description: "Web and API based SMTP testing tool"
 
+  atuin:
+    image: ghcr.io/atuinsh/atuin:v18.10.0
+    user: "${APP_UID}:${APP_GID}"
+    container_name: "${COMPOSE_PROJECT_NAME}-atuin"
+    restart: unless-stopped
+    networks:
+      - ${COMPOSE_NETWORK_NAME}
+    volumes:
+      - "${COMPOSE_PROJECT_NAME}_atuin_config:/config"
+    ports:
+      - "${ATUIN_PORT}:8888"
+    environment:
+      - PUID=${APP_UID}
+      - PGID=${APP_GID}
+      - ATUIN_HOST=0.0.0.0
+      - ATUIN_PORT=8888
+      - ATUIN_OPEN_REGISTRATION=true
+      - ATUIN_DB_URI=postgres://${ATUIN_DB_USERNAME}:${ATUIN_DB_PASSWORD}@atuin-db:5432/${ATUIN_DB_NAME}
+      - RUST_LOG=info,atuin_server=debug
+    depends_on:
+      - atuin-db
+    command: server start
+    healthcheck:
+      test: ["CMD-SHELL", "test -f /proc/net/tcp && grep -q ':2288' /proc/net/tcp"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 40s
+    labels:
+      homepage.group: "Developer Tools"
+      homepage.name: "Atuin"
+      homepage.icon: "atuin.png"
+      homepage.href: "http://192.168.3.6:${ATUIN_PORT}"
+      homepage.description: "Magical shell history synchronization"
+
+  atuin-db:
+    image: postgres:14
+    container_name: "${COMPOSE_PROJECT_NAME}-atuin-db"
+    restart: unless-stopped
+    networks:
+      - ${COMPOSE_NETWORK_NAME}
+    volumes:
+      - "${COMPOSE_PROJECT_NAME}_atuin_db_data:/var/lib/postgresql/data"
+    environment:
+      - PUID=${APP_UID}
+      - PGID=${APP_GID}
+      - POSTGRES_USER=${ATUIN_DB_USERNAME}
+      - POSTGRES_PASSWORD=${ATUIN_DB_PASSWORD}
+      - POSTGRES_DB=${ATUIN_DB_NAME}
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U ${ATUIN_DB_USERNAME} -d ${ATUIN_DB_NAME}"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 40s
+    labels:
+      com.docker.compose.project: "tsysdevstack-supportstack-demo"
+
   # =============================================================================
   # ARCHIVAL & CONTENT MANAGEMENT
   # =============================================================================
@@ -447,3 +505,7 @@ volumes:
     driver: local
   ${COMPOSE_PROJECT_NAME}_redis_data:
     driver: local
+  ${COMPOSE_PROJECT_NAME}_atuin_config:
+    driver: local
+  ${COMPOSE_PROJECT_NAME}_atuin_db_data:
+    driver: local