feat: add SEO-friendly blog post URL routing (/blog/:slug)

Add 301 redirect from /blog/:slug to /blog-post.html?slug=:slug
for cleaner, more SEO-friendly blog post URLs.

Enables access via:
https://agenticgovernance.digital/blog/tractatus-research-working-paper-v01

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/server.js

@@ -122,6 +122,12 @@ app.use((req, res, next) => {
   next();
 });
 
+// Blog post URL rewriting: /blog/:slug → /blog-post.html?slug=:slug
+// This provides cleaner URLs for blog posts (SEO-friendly)
+app.get('/blog/:slug', (req, res) => {
+  res.redirect(301, `/blog-post.html?slug=${req.params.slug}`);
+});
+
 // Static files
 app.use(express.static('public'));