nook: dispatch /agents, /changelog and /faq at the top level

The new subdomain pages 404ed in production: the vercel.json host
rewrites do not fire — SSR sees /agents, never /nook/agents — so pages
that only exist under src/routes/nook/* are unreachable from the
subdomain. Every pre-existing subdomain surface survives on top-level
host-dispatch routes (index, privacy, checkout, deletion), which is why
only the new pages broke. Give the three pages the same dispatch,
falling back to 404 on other sites.

Tests: full bun test run unchanged (539 pass); vinxi build clean.

Issue: FRE-12

src/routes/faq.tsx

@@ -0,0 +1,23 @@
+import { Switch, Match } from "solid-js";
+import { useSite } from "~/context/SiteContext";
+import NotFound from "./[...404]";
+import NookFaqPage from "./nook/faq";
+
+/**
+ * Host-aware FAQ route — `/faq`.
+ *
+ * The FAQ is a Nook-subdomain surface; all other sites fall back to 404.
+ * Mirrors the dispatch pattern in `src/routes/index.tsx` and
+ * `src/routes/checkout.tsx` — production does not apply the vercel.json
+ * host rewrites (SSR sees `/faq`, never `/nook/faq`).
+ */
+export default function FaqPage() {
+  const site = useSite();
+  return (
+    <Switch fallback={<NotFound />}>
+      <Match when={site().id === "nook"}>
+        <NookFaqPage />
+      </Match>
+    </Switch>
+  );
+}