fix(security): Schafskopf - run container as non-root node user

Dockerfile

@@ -1,7 +1,9 @@
 FROM node:20-alpine
+RUN mkdir -p /app && chown -R node:node /app
 WORKDIR /app
-COPY package*.json ./
+USER node
+COPY --chown=node:node package*.json ./
 RUN npm install --omit=dev
-COPY . .
+COPY --chown=node:node . .
 EXPOSE 7849
 CMD ["node", "server/index.js"]