Clean up the test repository from the registry at the end of the test step

CI_CD_PIPELINE_SETUP_GUIDE.md

@@ -605,10 +605,29 @@ curl http://localhost:5000/v2/test/tags/list
 docker rmi localhost:5000/test:latest
 docker pull localhost:5000/test:latest
 
-# Clean up test image
+# Clean up test image completely
+# Remove from local Docker
 docker rmi localhost:5000/test:latest
+
+# Delete test image from registry using registry API
+# Get the digest of the latest tag
+DIGEST=$(curl -s -H "Accept: application/vnd.docker.distribution.manifest.v2+json" http://localhost:5000/v2/test/manifests/latest | grep -o '"digest":"[^"]*"' | cut -d'"' -f4)
+
+# Delete the manifest from registry
+if [ ! -z "$DIGEST" ]; then
+    echo "Deleting test image from registry..."
+    curl -X DELETE http://localhost:5000/v2/test/manifests/$DIGEST
+else
+    echo "Could not find digest for test image"
+fi
+
+# Clean up test file
 rm /tmp/test.Dockerfile
 
+# Verify registry is empty
+echo "Registry contents after cleanup:"
+curl http://localhost:5000/v2/_catalog
+
 # Exit SERVICE_USER shell
 exit
 ```