Publish development images

.github/workflows/dev-container.yml builds and checks the development image for pull requests. Pushes to main also publish latest and sha-<commit> tags to ghcr.io/<owner>/<repository>/dev, using lowercase repository names. For this repository, use ghcr.io/jgoppert/fastdyn/dev:latest. Same-repository pull requests publish a pr-<number> preview tag and a sha-<head-commit> tag; pull requests from forks only build and check the image. Each tag becomes available after the corresponding Development container workflow finishes publishing it.

The image is generated from the same Nix development shell, including its compiler setup hooks. There is no separate Dockerfile or package list. Nix store caching reuses the compiler, QEMU, and Python dependencies; layered images also reuse unchanged layers in the registry. Documentation edits do not rebuild the native FastDyn plugin. Builds run on pushes rather than a nightly schedule.

For a new repository, GitHub may initially create a private container package. Its administrator can select Package settings → Change visibility → Public to allow readers to pull without signing in. The workflow uses the repository’s GITHUB_TOKEN to publish and needs no personal access token.

The general documentation walks through building the image with Nix, loading it into Docker, sharing an archive, and running the container. That chapter also covers source mounts, host-owned results, port forwarding, and a documentation preview. You need only Docker to use a published image; the workflow uses Nix on the build machine.