fix: Dockerfile.website - proper multi-stage build for blog generation

Dockerfile.website

@@ -1,26 +1,16 @@
-FROM node:20-alpine
+FROM node:20-alpine AS builder
 
-WORKDIR /app
+WORKDIR /app/www
+COPY www/package.json www/package-lock.json ./
+RUN npm install
 
-# Install dependencies for blog build
-COPY www/package.json ./www/package.json
-RUN cd www && npm install --silent 2>/dev/null || true
+COPY www/ ./
+RUN node build-blog.js
 
-# Copy www source files
-COPY www/ /app/www/
+FROM nginx:alpine
 
-# Build blog (processes _posts/*.md to blog/*.html)
-RUN node www/build-blog.js
-
-# Run envsubst on HTML files
-RUN apk add --no-cache gettext && \
-    chmod +x /docker-entrypoint.d/*.sh 2>/dev/null || true
-
-# Copy entrypoint
+COPY --from=builder /app/www/ /usr/share/nginx/html/
 COPY docker-entrypoint.d/ /docker-entrypoint.d/
 RUN chmod +x /docker-entrypoint.d/*.sh
 
-# Copy to nginx document root
-COPY --from=0 /app/www/ /usr/share/nginx/html/
-
 ENTRYPOINT ["/docker-entrypoint.d/30-envsubst.sh", "--", "nginx", "-g", "daemon off;"]