feat: Release version 1.3.1 with Docker optimization and comprehensive documentation

- Update version to 1.3.1 in package.json and docker-compose.yml
- Optimize Dockerfile with proper data directory structure for production
- Add comprehensive Docker documentation (DOCKER.md)
- Include deployment and backup scripts (deploy.sh, backup.sh)
- Add .env.example for environment configuration
- Improve README with detailed deployment instructions
- Fix database path handling for Docker production environment
- Add health checks and proper Docker Compose configuration
- Remove development task documentation
- Update .gitignore to exclude backup directories

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

docker-compose.yml

@@ -1,14 +1,22 @@
 services:
   ap-pos:
-    image: marcogll/ap_pos:1.3-latest
+    image: marcogll/ap_pos:1.3.1
     container_name: ap-pos
     restart: unless-stopped
     ports:
       - "3111:3111"
     environment:
       NODE_ENV: production
+      SESSION_SECRET: ${SESSION_SECRET:-your-very-secret-key-change-it-in-production}
     volumes:
       - ap_pos_data:/app/data
+    healthcheck:
+      test: ["CMD", "wget", "--quiet", "--tries=1", "--spider", "http://localhost:3111/login.html"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 40s
 
 volumes:
   ap_pos_data:
+    driver: local