ci: fix pipeline by reverting to stable node:20-alpine base images

Dockerfile

@@ -1,8 +1,8 @@
 # Stage 1: Builder
-FROM registry.infra.mintel.me/mintel/nextjs:latest AS builder
+FROM node:20-alpine AS builder
 WORKDIR /app
 
-# Clean the workspace in case the base image is dirty
+# Clean the workspace
 RUN rm -rf ./*
 
 # Arguments for build-time configuration
@@ -18,8 +18,8 @@ ENV DIRECTUS_URL=$DIRECTUS_URL
 ENV SKIP_RUNTIME_ENV_VALIDATION=true
 ENV CI=true
 
-# Enable pnpm
-RUN corepack enable
+# Enable pnpm v10
+RUN corepack enable && corepack prepare pnpm@10.3.0 --activate
 
 # Copy lockfile and manifest for dependency installation caching
 COPY pnpm-lock.yaml package.json .npmrc* ./
@@ -37,9 +37,17 @@ COPY . .
 RUN pnpm build
 
 # Stage 2: Runner
-FROM registry.infra.mintel.me/mintel/runtime:latest AS runner
+FROM node:20-alpine AS runner
 WORKDIR /app
 
+# Install curl for health checks
+RUN apk add --no-cache curl
+
+# Create nextjs user and group
+RUN addgroup --system --gid 1001 nodejs && \
+    adduser --system --uid 1001 nextjs && \
+    chown nextjs:nodejs /app
+
 ENV HOSTNAME="0.0.0.0"
 ENV PORT=3000
 ENV NODE_ENV=production