blog: park the engine fixture behind draft:true until real prose lands

content/blog/hello-world-again.md

@@ -3,6 +3,7 @@ title: Hello World
 date: '2026-09-06'
 slug: hello-world-again
 description: Engine fixture — proves figure centering, build-time highlighting, tables. Prose to be written.
+draft: true
 ---
 
 Skeleton post. Each element below exercises one rendering path of the blog engine; prose comes later.