feat: add blog system with static site generator

- Add blog posts in Markdown (_posts/)
- Build script converts MD to HTML at container build time
- First posts: building with AI lessons, quick start guide
- AGENTS.md documents blog writing style (unixsheikh-inspired)

Dockerfile.website

@@ -1,11 +1,26 @@
-FROM nginx:alpine
+FROM node:20-alpine
 
-COPY www/ /usr/share/nginx/html/
-COPY docker-entrypoint.d/ /docker-entrypoint.d/
+WORKDIR /app
 
+# Install dependencies for blog build
+COPY www/package.json ./www/package.json
+RUN cd www && npm install --silent 2>/dev/null || true
+
+# Copy www source files
+COPY www/ /app/www/
+
+# 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
+    chmod +x /docker-entrypoint.d/*.sh 2>/dev/null || true
+
+# Copy entrypoint
+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;"]
-
-CMD ["nginx", "-g", "daemon off;"]