Add Docker containerization support

[cj-vana]

Summary

• Add Dockerfile with multi-stage Python 3.11 build
• Add docker-compose.yml with environment variable configuration
• Add docker-compose.standalone.yml for Portainer/NAS deployment
• Add docker/entrypoint.sh for config initialization
• Add .dockerignore for build optimization
• Add DOCKER.md with complete deployment documentation
• Update README.md with Docker installation instructions
• Add cryptography to requirements.txt for alert_command plugin

Features

• Connection Types: Serial (USB), TCP, and BLE support
• Environment Variables: Override config.ini settings via environment
• Web Viewer: Exposed on configurable port (default 8080)
• Health Check: Python-based health check for container monitoring
• Portainer Ready: Standalone compose file for easy deployment

Test Plan

• Build Docker image successfully
• Container starts and connects to MeshCore device via serial
• Web viewer accessible on configured port
• Health check reports healthy status
• Environment variable overrides work correctly

[agessaman]

Hi. Thanks for this. Docker support and a pre-built docker image is something I want to add. I'd like to get #23 merged first so the docker container is built against the new structure using the proper entry points and the docker container can take advantage of the --config parameter.

[cj-vana]

Hi. Thanks for this. Docker support and a pre-built docker image is something I want to add. I'd like to get #23 merged first so the docker container is built against the new structure using the proper entry points and the docker container can take advantage of the --config parameter.

Sounds good! Let me know if you need me to do any refactoring once that is done.

[tbaumann]

Nix support is merged. Some of it should help you a lot.

[smithpl2000]

Is anything to help ? I can add portainer, traefik as publisher with authorization for Web server
I've made my own implementation
meshcore-bot as container on my Synology NAS with docker engine and meshcore node by BLE