Consolidate all moonweb.org sites under www.moonweb.org

- Migrate timecapsule (old www.moonweb.org) into monorepo as Eleventy 2.x site
- Change all site URLs from subdomains to subdirectories under www.moonweb.org
- Replace Cloudflare Pages deployment with IONOS SFTP
- Update site-switcher, footer, and all internal links
- Add merge script for combining all sites into single deployment
- Update CI/CD workflow for IONOS SFTP deployment
- Update stefankoelle.de references to use new URLs
- Update AGENTS.md and README.md documentation

timecapsule/src/sitemap.xml.njk

@@ -0,0 +1,12 @@
+---
+permalink: "/timecapsule/sitemap.xml"
+eleventyExcludeFromCollections: true
+---
+<?xml version="1.0" encoding="utf-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+{%- for page in collections.all %}{% if page.data.layout != "redirect.njk" and page.data.permalink != "/sitemap.xml" and page.url != "/404/" %}
+  <url>
+    <loc>{{ site.domain }}{{ page.url }}</loc>{% if page.data.lastChanged %}
+    <lastmod>{{ page.data.lastChanged | toIsoDate }}</lastmod>{% endif %}
+  </url>{% endif %}{% endfor %}
+</urlset>