Publish the Docker image to GHCR

[luisalrp]

Problem or motivation

It would be helpful if the project published an official Docker image to GitHub Container Registry (GHCR).

The current docker-compose.yml uses:
build: .

This requires cloning the repository and building the image locally. Publishing an image such as ghcr.io/pascalorg/editor would make deployment and updates much easier.

The Compose configuration could then use: image: ghcr.io/pascalorg/editor:latest

Thanks for considering it!

Proposed solution

Publish the Docker image to GHCR, for example: ghcr.io/pascalorg/editor:latest

The Compose configuration could then use: image: ghcr.io/pascalorg/editor:latest

Ideally, images could be published automatically for releases and tagged with both the release version and latest.

Alternatives considered

Continue cloning the repository and building the image locally with build: ., although this makes deployment and updates less convenient.

Additional context

Current Compose file:
https://github.com/pascalorg/editor/blob/main/docker-compose.yml

Thanks for considering it!

[luisalrp]

I opened #771 to address this request.

The PR:

• Publishes the editor image from the release workflow to GHCR.
• Publishes stable version tags and latest.
• Keeps beta and recovery releases from overwriting latest.
• Publishes both linux/amd64 and linux/arm64 images.
• Updates Docker Compose to use the published image by default.

One maintainer action is still required after the first publication: set the ghcr.io/pascalorg/editor package to Public and connect it to pascalorg/editor.

Reducing the current image size is intentionally left as a separate follow-up.