Confirm the site redeploys from the tagged commit on the first release #39

The redeploy-site job in ci.yml starts the Pages workflow again after a release, so the explorer's footer links to the release page rather than the commit. It runs only when the Release job's Record whether a release was cut step finds a tag on HEAD, which only a release gives, so it has not run for real yet. Merging the explorer's PWA changes (#37, #38) released nothing, and the job was skipped.

What has been checked without a release: actionlint and zizmor pass on the workflow, a build in a clone with a release tag on HEAD gives a release identity with a releases/tag/ link, and the site deploys from main as a commit identity today.

Deferred until the first release after #37. Then confirm that redeploy-site ran, that a Pages run started from the tagged release commit, and that the footer at https://exadev.github.io/combinatrix/ shows v<version> linking to that release. If gh workflow run is refused with the job's token, the job needs a different way to start the workflow.