Derive the docs version instead of hardcoding it

[energyscholar]

Small follow-on to your docs pass this morning — different thing, so I split it out.

docs/source/conf.py had version = "2.1.1" hardcoded. It has to be bumped by hand, so it drifted: it was already stale for 2.1.2 and stayed stale through 2.1.3.

The reason nobody noticed is worth a sentence, because it's the actual bug. Only version was set, and sphinx_rtd_theme renders release. So the wrong number existed but was never displayed anywhere a reader could see it — the page title read "ewstools documentation" with no version at all.

This resolves the version instead:

1. installed package metadata — which is how the docs are really built, since .readthedocs.yaml pip-installs the package and so does CI
2. pyproject.toml, for a tree where the package isn't installed
3. a literal fallback

and sets release as well as version, so it's actually rendered.

The resolver cannot raise. fail_on_warning: true is set, so an exception in conf.py would take the whole build down; every branch is wrapped and the last resort is the string unknown.

Verification

Built exactly as RTD does (docs/requirements.txt + the package, sphinx-build -W). Build clean, and the rendered title is now:

$ grep -o '[^<>]*2\.1\.3[^<>]*' index.html
ewstools &mdash; ewstools 2.1.3 documentation

Also checked the two fallbacks in isolation, since the first branch normally hides them: with the package absent it returns 2.1.3 from pyproject.toml, and on an interpreter without tomllib (3.10 and earlier) it returns unknown rather than raising.

One thing I did not change

.zenodo.json also pins "version": "v2.1.1" and a hardcoded "publication_date": "2023-02-10". I was going to clean those up in the same PR, but I couldn't confirm from Zenodo's own documentation what happens when those fields are omitted — their docs say publication_date defaults to the current date, but say nothing about version being taken from the release tag. Rather than guess in a metadata file, I've left it alone and mentioned it separately. It looks inert anyway: the Zenodo API only has the one 2023 record, so the GitHub integration doesn't appear to be firing.

No rush on this one.

[ThomasMBury]

thanks - looks good

[ThomasMBury]

looks good