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/routes/agents.tsx

@@ -7,12 +7,12 @@ import { pageMeta } from "~/meta";
 import "~/styles.css";
 
 export const Route = createFileRoute("/agents")({
-  head: () => ({
-    meta: pageMeta(
-      "Supported agents – Every coding agent Paseo runs | Paseo",
-      "Run Claude Code, Codex, OpenCode, Cursor CLI, Gemini CLI, Hermes Agent, Qwen Code, Kimi Code, DeepSeek TUI, and 28 more coding agents from your phone. Self-hosted, your code stays on your machine.",
+  head: () =>
+    pageMeta(
+      "Supported agents – Every coding agent Paseo runs",
+      "Run Claude Code, Codex, Copilot, OpenCode, Cursor CLI, Gemini CLI, and dozens more coding agents from your phone. Self-hosted, your code stays on your machine.",
+      "/agents",
     ),
-  }),
   component: AgentsPage,
 });