NEWS RELAUNCH CUTOVER: promote the hub to /, feed to /news, go public

The big flip. /home3 (hub) becomes /; the feed lives at /news; both indexable.
- PROMOTE: routes/+page.svelte is now the hub (was the interim NewsFeed wrapper);
  noindex removed; "Read more good news" → /news. routes/home3 + home2 deleted.
- routes/+page.js: redirects legacy root-query links (/?view=latest, /?tag, /?source,
  /?q, /?view=today→highlights) to /news before the hub renders (no flash).
- /news: noindex dropped (route meta + Caddy @newsHidden removed); now public.
- LINKS: HubBar brand/Home → /, News default → /news; HubShell/art/play back → /;
  account Following + share.py Explore/Browse/source → /news.
- FOOTER: one shared Footer.svelte (motto + Send feedback + slot) across Hub/News/
  Play/Art/HubShell/Account/Zen; global layout footer removed (FeedbackModal stays).
- SITEMAP: + /news /art /play /word /quote /onthisday; cap 5k→50k; gated on
  has-summary; paywalled excluded; HEAD now 200 (api_route GET+HEAD).
- Head-patcher: /news entry. PWA + shell description broadened to the hub.
- Caddy: @newsHidden dropped; @hidden now admin-only (word/quote/onthisday public);
  /home2,/home3 → / 301. Mirrored to deploy/caddy snapshot.

425 backend + 36 frontend tests green; build clean; Caddy valid.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/routes/zen/+page.svelte

@@ -4,6 +4,7 @@
   import { page } from '$app/stores';
   import { auth } from '$lib/auth.svelte.js';
   import { isDevGated, blockedForViewer } from '$lib/devgate.js';
+  import Footer from '$lib/components/Footer.svelte';
 
   let canvas = $state();
   let failed = $state(false);
@@ -119,6 +120,8 @@
   {/if}
 </main>
 
+<Footer />
+
 <style>
   header.bar { background: var(--surface); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 20; }
   .inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }