[chrismattmann]

The Documentation badge reads failing after almost every merge to master, and the docs are fine.

Two runs start on every push and fight over the same concurrency group:

CI             push  success    2026-11-09T22:00:27Z
Documentation  push  cancelled  2026-11-09T22:00:27Z
Documentation  push  cancelled  2026-11-09T21:59:51Z
CI             push  success    2026-11-09T21:59:51Z

Identical timestamps. ci.yml had a docs: job calling documentation.yml via workflow_call, and documentation.yml triggers on push to master itself. Both hold concurrency: group: "pages", so one gets cancelled — and GitHub renders a cancelled run as a failing badge, on exactly the workflow the README badge points at.

It wasn't only cosmetic

Under workflow_call from a push, github.event_name is still 'push' — so the deploy job's if was true in the called run as well. Both runs were deploying the same commit to GitHub Pages, and only the concurrency group stopped them doing it simultaneously.

The change

• ci.yml no longer calls it. That job's real value was building docs on pull requests, so documentation.yml now takes pull_request directly. Deployment stays gated on a push to master, so a PR builds the docs without publishing them. One run per event.
• The concurrency group moves from the workflow to the deploy job. At workflow level it could cancel a queued build, which is how two merges 36 seconds apart produced a red badge over documentation that had built perfectly. Deployments still serialise — which is what Pages requires — and an in-progress deployment still finishes.

Before changing job names

master has no branch protection and no required status checks, so dropping docs / Build documentation with Sphinx from the CI run breaks no gate. The same check now arrives from the Documentation workflow instead.

Residual case

Three or more pushes to master inside a single deploy still leaves a superseded deployment cancelled. That outcome is correct — skipping a docs deploy for a commit that's already two commits stale is what you want — it just means the badge can still go red in that narrow case. Worth knowing rather than discovering again.

This PR exercises the change: documentation.yml should appear once on it, building but not deploying.

[coveralls]

coverage: 70.13%. remained the same — stop-running-the-docs-workflow-twice into master