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/src/server-entry.ts

@@ -0,0 +1,18 @@
+import startEntry from "@tanstack/react-start/server-entry";
+
+const CANONICAL_HOST = "paseo.sh";
+
+type FetchArgs = Parameters<typeof startEntry.fetch>;
+
+export default {
+  async fetch(...args: FetchArgs): Promise<Response> {
+    const [request] = args;
+    const url = new URL(request.url);
+    if (url.hostname !== CANONICAL_HOST || url.protocol !== "https:") {
+      url.protocol = "https:";
+      url.hostname = CANONICAL_HOST;
+      return Response.redirect(url.toString(), 301);
+    }
+    return startEntry.fetch(...args);
+  },
+};