The build job bind-mounts the shared pages tree (the runner whitelists it
via container.valid_volumes) and, on tag pushes, wipes
/data/gitea-pages/<owner>/<repo>/<tag>/coverage before copying the c8 report
into it. Only this tag's coverage/ is touched; older tags and sibling
docs/landing trees are left for manual pruning.
Add a `tags: ["*"]` push trigger: a `branches` filter alone matches no tag
ref, so the tag-gated publish job (and this coverage step) could never run.
Track per-branch coverage as a backlog task.