fix: use docker image best practice for node user

src/frontend/Dockerfile

@@ -1,17 +1,16 @@
 FROM node:20-alpine AS frontend-deps
 
+USER node
+
 WORKDIR /home/frontend/
 
-COPY ./src/frontend/package.json ./package.json
-COPY ./src/frontend/package-lock.json ./package-lock.json
+COPY --chown=node:node ./src/frontend/package.json ./package.json
+COPY --chown=node:node ./src/frontend/package-lock.json ./package-lock.json
 
 RUN npm ci
 
-COPY .dockerignore ./.dockerignore
-COPY ./src/frontend/ .
-
-# Ensure the directory is writable by uid 1000 (for Kubernetes security context)
-RUN chown -R 1000:1000 /home/frontend
+COPY --chown=node:node .dockerignore ./.dockerignore
+COPY --chown=node:node ./src/frontend/ .
 
 ### ---- Front-end builder image ----
 FROM frontend-deps AS meet
@@ -20,6 +19,8 @@ WORKDIR /home/frontend
 
 FROM frontend-deps AS meet-dev
 
+USER node
+
 WORKDIR /home/frontend
 
 EXPOSE 8080