Initial commit: Astro 6 static blog site

- German (default) and English i18n support
- Categories and tags
- Blog posts with hero images
- Dark/light theme switcher
- View Transitions removed to fix reload ghost images
- Webmentions integration
- RSS feeds per locale

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/pages/schlagwort/[slug].astro

@@ -0,0 +1,13 @@
+---
+import TagDetailPage from '~/components/TagDetailPage.astro';
+import { getTagsByLocale } from '~/i18n/posts';
+
+export async function getStaticPaths() {
+	const tags = await getTagsByLocale('de');
+	return tags.map((tag) => ({ params: { slug: tag.slug }, props: { tag } }));
+}
+
+const { tag } = Astro.props;
+---
+
+<TagDetailPage locale="de" tag={tag} />