v0.13.0 - Remove support of secrets.json and other improvements

What's Changed

• Dev - Remove support of secrets.json and other improvements #166 by @stanfrbd in #170

Usage improvements

• Adds a healthcheck in the docker image.
• Adds a secrets.json → .env migration script with safe value quoting and optional sample validation.

Security

• Completes the transition away from secrets.json toward .env / environment-variable-only configuration.
• Removes the unauthenticated /config GUI endpoint.
• Changes docker permissions: add a cyberbro user in the container
• Removes supervisord in the container
• Updates docs, Docker image tagging, and CI triggers.

Full Changelog: v0.12.0...v0.13.0