Should we rethink our release cadence + Docker image publishing?

[animmosmith]

Been building pyopia-gui against PyOPIA the last few days and ran into
something worth talking about before we next catch up.

The Docker support (Dockerfile, docs, compose.yaml) has been sitting on main
since before v2.0.3 (back in Sep 2024) but never made it into an actual
release, and the image itself was never published by CI either (#424). So
anyone outside our GH org trying to follow the README's docker instructions
just hits a wall - it looks finished and documented but isn't actually usable.

Two things I think are worth changing:

• Cut releases when something's actually done, not on a fixed schedule. If a
  feature (like the Docker stuff) is finished, it should go in the next
  release rather than sit around indefinitely.
• The Docker image publish should be part of the release process itself, not
  a separate manual step - otherwise it just drifts out of sync, which is
  basically what happened here.

Also worth considering: a Zenodo DOI per release. It's free and basically
automatic once the repo's linked, and since people cite PyOPIA in papers,
having an exact citable version (rather than "whatever main was on some
random date") seems worth doing.

Nothing urgent, just want to get this on the radar before we talk.

[nepstad]

The Docker support was never finished, but we should do that and set up the building of PyOPIA docker images on docker hub (integrated in the build-test system). And fix the README accordingly.

I like the Zenodo / DOI suggestion.

We have no official Release schedule or guidelines for this yet, but this might be a good time to start that.

[animmosmith]

Splitting this into concrete tracked issues:

• Release cadence philosophy: closed via Develop a Release philosophy, guidance and schedule (ish) for PyOPIA #428 (now in Summer 26 Housekeeping: tests, docs, CI, and bug fixes #430, the README's Releases section)
• Docker image publish as part of the release process: tracked in ghcr.io/sintef/pyopia image isn't publicly pullable, despite the README instructing anonymous docker run #424
• Zenodo DOI per release: tracked in Publish a Zenodo DOI per release #432

Closing this in favour of those three.