Closes the push route into ci-image.yml (#744) and ships the persist-credentials guard that was waiting on it (#835).
ci-image.yml's push trigger had no branches: filter and was path-scoped to docker/ci/** AND to the workflow file itself. Gitea resolves a push workflow's definition from the pushed ref, so any branch push touching those paths ran that branch's own YAML on a docker-capable runner holding the credential that writes ersatztv:prod and the ersatztv-ci:<sha> five container: jobs execute.
Be precise about what the filter buys: it is loaded from the pushed ref like the rest of the file, so a branch that deletes it re-enables the route. This closes the DRIVE-BY case - publication as a side effect of an ordinary push - and is not a boundary against a writer who intends to run their own YAML. The wider class is #853.
The self-reference left both paths: and ci-image-pin's expected in the same change - a decided tradeoff with both prices stated, not a necessity. Branch publishing moves to workflow_dispatch, probed live: run 2340 on this branch published ersatztv-ci:43b1e45 and left :latest unchanged.
With both mechanical blockers gone, ci-image.yml's checkout takes persist-credentials: false (16 of 16) and scripts/tests/test_workflow_persist_credentials.py holds the convention with NO exemption list - git-index population, declared clause mutation re-run every suite, guard-inventory rows.
fixes#744fixes#835
Co-authored-by: Timothy <timothy@noreply.gitea.tblindustries.be>
