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/art/+page.svelte

@@ -3,6 +3,7 @@
   import { getJSON } from '$lib/api.js';
   import { afterNavigate, goto } from '$app/navigation';
   import HubBar from '$lib/components/HubBar.svelte';
+  import Footer from '$lib/components/Footer.svelte';
 
   // Virtual frames the viewer can switch between — remembered locally, no account needed.
   const FRAMES = [
@@ -38,7 +39,7 @@
   afterNavigate(({ from }) => { if (from) cameFromApp = true; });
   function goBack() {
     if (cameFromApp && typeof history !== 'undefined') history.back();
-    else goto('/home3', { replaceState: true });
+    else goto('/', { replaceState: true });
   }
 
   // Woods are built from four real mitered rails (grain turns at the corners); metals/none aren't.
@@ -213,7 +214,7 @@
     {/if}
   </main>
 
-  <footer class="foot">upbeatBytes — no ads, no paywalls, no doomscrolling.</footer>
+  <Footer />
 </div>
 
 {#if zoom && art}
@@ -489,11 +490,6 @@
 
   .note { color: var(--muted); font-size: 1.05rem; margin-top: 40px; }
 
-  .foot {
-    text-align: center; color: var(--muted); font-size: 0.84rem;
-    padding: 28px 16px 36px; border-top: 1px solid var(--line); margin-top: 24px;
-  }
-
   .lightbox {
     position: fixed; inset: 0; z-index: 50; border: none; cursor: zoom-out;
     /* A soft, top-lit gallery wall — lighter than the page so every frame (Black