Add more cleanup options.

run.sh

@@ -137,6 +137,11 @@ while true; do
     --discover
 
   # Cleanup any build leftovers
+  if [[ "${SYSTEM_PRUNE:-false}" == "true" ]]; then
     docker system prune --all --force
-  sleep 15
+  fi
+  if [[ "${WEBAPP_IMAGE_PRUNE:-true}" == "true" ]]; then
+    docker image rm -f $(docker image ls --quiet --filter 'reference=laconic-webapp')
+  fi
+  sleep ${CHECK_INTERVAL:-15}
 done