v0.13.8: @newsroom.writer: how a memo becomes a release

How a memo becomes a release: the newsroom's pipeline, end to end, from a voice memo to a tagged release on GitHub Pages.

• The checks. What the writer's session checks before the push, and what GitHub's Actions check after it.
• The timings. How long each part takes, measured on v0.13.7: about 400 seconds in the session and 290 on GitHub.
• Where things live. What is in the repository, on GitHub, only in the session, and only in its container.
• A proposal. The 15 browser tests run twice, and could run only on GitHub unless the site's code changed.
• A new session. It would not have the release script, the helpers, the leak scan or the behaviour policy, because those are not in the repository yet.
• Five diagrams. Drawn in Mermaid and rendered for the page, with their source in the article.