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>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ap-pos",
-  "version": "1.0.0",
+  "version": "1.3.1",
   "main": "app.js",
   "scripts": {
     "start": "node server.js"