The delimiter ban protecting `build`'s `Smoke + IPTV E2E` was enforced only by a pytest in `script-tests` — `on: pull_request`, not a required context — so nothing re-checked it on a `v*` tag push, which is exactly when the candidate image is published. A `scan` job now runs the ban test and `build` lists it in `needs:`, so a red `scan` skips `build` and no image is built.
Measured both directions without cutting a release: run 1928 (poisoned Smoke) → scan failed, `Build & push` skipped; run 1929 (control) → scan green, build ran.
The gate rests on three different KINDS of check, because each single kind was defeated in review: the ban test; an execution probe against a poisoned copy with all three `env:` tiers layered; and `scripts/ci-prove-ban-detects.sh`, which is not a test — it poisons the real checkout and vouches only for the ban test's `build` parametrisation failing. Eight review rounds; rounds 1-5 each found a real defect in the previous fix.
Refs: #767
Decisions-Edit: yes
Co-authored-by: Timothy <timothy@noreply.gitea.tblindustries.be>