diff --git a/.github/scripts/install-trivy.sh b/.github/scripts/install-trivy.sh
index 03cb253..e993d11 100644
--- a/.github/scripts/install-trivy.sh
+++ b/.github/scripts/install-trivy.sh
@@ -1,19 +1,55 @@
 #!/usr/bin/env bash
 set -euo pipefail
-# Release assets and these platform names were checked against v0.76.1.
+# Public OCI index pins the platform-specific executable without GitHub API access.
 version=0.76.1
+image=ghcr.io/aquasecurity/trivy:0.76.1@sha256:790fd66d1697395d8693d1acaa1ea702406a20f109b6fc7bac8db623eca6c06c
+evidence_dir="${1:-evidence/scanner-install}"
+mkdir -p "$evidence_dir" .ci-tools
+stage=host-platform
+platform=
+cid=
+finish() {
+  result=$?
+  trap - EXIT
+  if [[ -n "$cid" ]]; then
+    docker rm -f "$cid" >/dev/null 2>&1 || true
+  fi
+  rm -f .ci-tools/trivy.new
+  python3 - "$evidence_dir/install.json" "$result" "$stage" "$image" "$platform" "$version" <<'PY'
+import hashlib
+import json
+from pathlib import Path
+import sys
+path, code, stage, image, platform, version = sys.argv[1:]
+record = {
+    "status": "installed" if code == "0" else "failed",
+    "exit_code": int(code), "stage": stage, "image": image, "platform": platform,
+    "binary_source": "/usr/local/bin/trivy", "expected_version": version,
+}
+if code == "0":
+    record["binary_sha256"] = hashlib.sha256(Path(".ci-tools/trivy").read_bytes()).hexdigest()
+Path(path).write_text(json.dumps(record, indent=2) + "\n")
+PY
+  exit "$result"
+}
+trap finish EXIT
 case "$(uname -m)" in
-  x86_64) platform=64bit ;;
-  aarch64|arm64) platform=ARM64 ;;
+  x86_64) platform=linux/amd64 ;;
+  aarch64|arm64) platform=linux/arm64 ;;
   *) echo "Unsupported scanner host architecture" >&2; exit 1 ;;
 esac
-mkdir -p .ci-tools
-asset="trivy_${version}_Linux-${platform}.tar.gz"
-gh release download "v${version}" --repo aquasecurity/trivy \
-  --pattern "$asset" --pattern "trivy_${version}_checksums.txt" --dir .ci-tools
-(
-  cd .ci-tools
-  grep "  ${asset}$" "trivy_${version}_checksums.txt" | sha256sum --check --strict -
-  tar -xzf "$asset" trivy
-)
-echo "$PWD/.ci-tools" >> "$GITHUB_PATH"
+stage=pull
+docker pull --platform "$platform" "$image"
+stage=create
+cid=$(docker create --platform "$platform" "$image")
+stage=extract
+docker cp "$cid:/usr/local/bin/trivy" .ci-tools/trivy.new
+chmod 0755 .ci-tools/trivy.new
+stage=verify-version
+.ci-tools/trivy.new --version | grep -Fx "Version: $version"
+mv .ci-tools/trivy.new .ci-tools/trivy
+stage=publish-path
+if [[ -n "${GITHUB_PATH:-}" ]]; then
+  echo "$PWD/.ci-tools" >> "$GITHUB_PATH"
+fi
+stage=complete
diff --git a/.github/workflows/image-release.yml b/.github/workflows/image-release.yml
index bd8b336..25a9765 100644
--- a/.github/workflows/image-release.yml
+++ b/.github/workflows/image-release.yml
@@ -110,9 +110,7 @@ jobs:
           if [[ -n "$release_id" ]]; then
             gh api --method PATCH "repos/$GITHUB_REPOSITORY/releases/$release_id" -F draft=true > evidence/draft-release.json
           fi
-      - name: Install verified scanner release
-        env:
-          GH_TOKEN: ${{ github.token }}
+      - name: Install pinned public OCI scanner
         run: bash .github/scripts/install-trivy.sh
       - name: Source/UI dependency vulnerability, secret and misconfiguration gate with SPDX SBOM
         run: python3 .github/scripts/image-policy.py source evidence/source
diff --git a/.github/workflows/pr-build.yml b/.github/workflows/pr-build.yml
index d51d6ee..7cc368d 100644
--- a/.github/workflows/pr-build.yml
+++ b/.github/workflows/pr-build.yml
@@ -27,6 +27,11 @@ jobs:
       - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
         with:
           persist-credentials: false
+      - name: Initialize retained runtime/scanner state
+        run: |
+          mkdir -p evidence/scanner-install
+          printf '%s\n' '{"status":"not_started","reason":"waiting_for_native_build_and_smoke"}' \
+            > evidence/scanner-install/install.json
       - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
         with:
           ref: ${{ github.sha }}
@@ -35,10 +40,6 @@ jobs:
       - uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3
       - name: Validate fail-closed policy helpers
         run: python3 .github/scripts/test-image-policy.py
-      - name: Install scanner
-        env:
-          GH_TOKEN: ${{ github.token }}
-        run: bash .github/scripts/install-trivy.sh
       - name: Build once, populating OCI metadata from CI
         env:
           BUILDX_METADATA_PROVENANCE: max
@@ -68,9 +69,12 @@ jobs:
           trap 'docker rm -f "$cid" >/dev/null' EXIT
           docker cp "$cid:/home/agent" "output-$ARCH"
       - name: Test production image
+        id: smoke
         run: sh source/deployments/docker/test-image.sh "$ARCH"
       - name: Strip binary
         run: tar -cf "agent-$ARCH.tar" -C "output-$ARCH" . && rm -rf "output-$ARCH"
+      - name: Install pinned public OCI scanner after runtime tests
+        run: bash .github/scripts/install-trivy.sh
       - name: Source/UI dependency and final image gates with SPDX SBOMs
         run: |
           failed=0
@@ -87,6 +91,22 @@ jobs:
           name: agent-${{ matrix.architecture }}.tar
           path: agent-${{ matrix.architecture }}.tar
           if-no-files-found: error
+      - name: Record runtime result independently of scanner availability
+        if: always()
+        env:
+          SMOKE_OUTCOME: ${{ steps.smoke.outcome }}
+        run: |
+          mkdir -p evidence
+          python3 - <<'PY'
+          import json
+          import os
+          from pathlib import Path
+          Path("evidence/runtime-smoke.json").write_text(json.dumps({
+              "architecture": os.environ["ARCH"],
+              "outcome": os.environ["SMOKE_OUTCOME"],
+              "workflow_revision": os.environ["GITHUB_SHA"],
+          }, indent=2) + "\n")
+          PY
       - name: Retain reports on failure
         if: always()
         uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4