Fix failed job #121670: update node to v22

frontend/Dockerfile

-# Build stage
-FROM node:21-alpine AS build
-
-# Build as non-root user
-RUN apk update && apk upgrade && adduser -D svelteuser
-USER svelteuser
-
+FROM node:22-alpine AS base
+RUN apk update && apk upgrade && apk add dumb-init
 WORKDIR /app
 
-COPY --chown=svelteuser:svelteuser package.json .
-COPY --chown=svelteuser:svelteuser package-lock.json .
+FROM base AS build
+# Build stage
+COPY package.json .
+COPY package-lock.json .
 RUN npm install
-
-COPY --chown=svelteuser:svelteuser . .
+COPY . .
 RUN npm run build
 
 # Production stage
-FROM node:21-alpine
-
-# Install dumb-init to handle signals properly and run as non-root user
-RUN apk update && apk upgrade && apk add dumb-init && adduser -D svelteuser
-USER svelteuser
-
-WORKDIR /app
-
-COPY --chown=svelteuser:svelteuser --from=build /app/build /app/package.json /app/package-lock.json ./
-COPY --chown=svelteuser:svelteuser --from=build /app/node_modules /app/node_modules
-
+FROM base
+COPY --from=build /app/build /app/package.json /app/package-lock.json ./
+COPY --from=build /app/node_modules /app/node_modules
 EXPOSE 8080
-
 ENV HOST=0.0.0.0 PORT=8080 NODE_ENV=production
-
 CMD ["dumb-init", "node", "index.js"]