- scripts/image-label-amd64.sh: index-safe read of the amd64 image's labels (OCI index with attestations, Docker manifest list, single manifest). - scripts/php-emergency-guard.sh: used by both build-push.yaml guard sites; same decisions as the old inline step on single-platform images, but FAILS CLOSED when the labels cannot be read (only "tag not found" passes). - lsphp-source-emergency.yaml: push by digest + assemble (copy of HMB assemble-multiarch-index.sh); optional arm64; refuses to replace a multi-arch production tag with amd64-only unless allow_amd64_only. - Tests wired into Shell-Checks; main build matrix platforms unchanged. Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_0185ukXjXyosSkunDsdWz3mb