Portfolio without downloads; Om mig, Kontakt and Posters come from the portal on the same domain

Linus 2026-11-06: everything public lives on imagesbyolofsson.se (Cleura), the customer
subdomain is only for ordering and the logged-in portal; photos are sold as posters
instead of being downloadable.

- Portfolio: download menu (S/M/L), the original password dialog and /download/original
  are gone; the lightbox has "Köp som poster" -> /posters instead.
- about.astro and contact.astro removed: Caddy on Cleura sends /about, /contact and
  /posters to the portal, so the About text and collaborations are edited once in admin.
  They stay in sitemap-0.xml (PORTAL_PAGES); the sitemap index lists /posters/sitemap.xml.
- Menu and 404 page link Posters; privacy, robots.txt and llms.txt no longer mention
  password downloads.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/pages/sitemap-index.xml.ts

@@ -9,6 +9,7 @@ export const GET: APIRoute = ({ site }) => {
   const body = `<?xml version="1.0" encoding="UTF-8"?>
 <sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
   <sitemap><loc>${new URL('/sitemap-0.xml', base).toString()}</loc></sitemap>
+  <sitemap><loc>${new URL('/posters/sitemap.xml', base).toString()}</loc></sitemap>
 </sitemapindex>
 `;
   return new Response(body, { headers: { 'Content-Type': 'application/xml; charset=utf-8' } });