fix(website): SEO canonicals, host redirects, sitemap, app noindex

Addresses the high-volume issues from the Ahrefs audit:
- Worker entrypoint 301s every request not on https://paseo.sh
  (www subdomain and http variants), killing the duplicate-page
  errors and the HTTP→HTTPS internal-link notices.
- pageMeta() emits <link rel="canonical"> and og:url per route;
  every head() call now passes its canonical path.
- /blog stops rewriting itself to /blog?drafts=false; the search
  param only appears when explicitly true.
- Sitemap includes /blog and each post.
- Trim homepage title under SERP truncation, rewrite /agents meta
  description under 160 chars, pad short descriptions on
  /privacy, /download, /cloud, /changelog, /docs.
- app.paseo.sh gets <meta robots=noindex,nofollow> and a
  Disallow-all robots.txt so the SPA shell stops polluting the
  crawl with H1-missing / no-OG / low-word-count warnings.

packages/website/vite.config.ts

@@ -53,6 +53,17 @@ function discoverAgentRoutes(): string[] {
     .map((slug) => `/${slug}`);
 }
 
+function discoverBlogRoutes(): string[] {
+  const postsDir = path.join(__dirname, "posts");
+  if (!fs.existsSync(postsDir)) return ["/blog"];
+  const slugs = fs
+    .readdirSync(postsDir, { withFileTypes: true })
+    .filter((entry) => entry.isFile() && entry.name.endsWith(".md"))
+    .map((entry) => entry.name.replace(/\.md$/, ""))
+    .sort();
+  return ["/blog", ...slugs.map((slug) => `/blog/${slug}`)];
+}
+
 const sitemapPages = [
   "/",
   "/agents",
@@ -62,6 +73,7 @@ const sitemapPages = [
   "/privacy",
   ...discoverAgentRoutes(),
   ...discoverDocsRoutes(),
+  ...discoverBlogRoutes(),
 ].map((routePath) => ({
   path: routePath,
 }));