test(ci): run no-device Echo guards

Run the eight fixture, device-identity and redaction guards in the existing verify lane without introducing device operations or additional dependencies.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.github/workflows/scanner.yml

@@ -37,6 +37,8 @@ jobs:
           cache-read-only: ${{ github.event_name == 'pull_request' }}
       - name: Verify source headers, whitespace, imports and JavaScript syntax
         run: node scripts/ci/check-source-standards.mjs
+      - name: Run no-device Echo fixture guard tests
+        run: node --test scripts/ci/scanner-echo-guards.test.mjs
       - name: Install required Android SDK packages
         run: |
           "$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager" "platforms;android-35" "build-tools;34.0.0" "build-tools;35.0.0" "platform-tools"