fix frontend build

Author: zeylos

src/frontend/Dockerfile

@@ -3,7 +3,7 @@ FROM node:22-slim AS frontend-deps
 ENV npm_config_cache=/tmp/npm-cache
 RUN npm install -g [email protected] && npm cache clean -f
 
-ARG DOCKER_USER
+ARG DOCKER_USER=1000
 WORKDIR /home/frontend/
 
 RUN chown -R ${DOCKER_USER} /tmp/npm-cache