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>

scripts/copy-sw.js

@@ -0,0 +1,17 @@
+// Copies sw.js + workbox-*.js from dist/server/ to dist/client/ after build.
+// @astrojs/node standalone only serves static files from dist/client/, but
+// @vite-pwa/astro generates the service worker into dist/server/ during the
+// SSR Vite build pass.
+import { copyFile, readdir } from "node:fs/promises";
+import { join } from "node:path";
+
+const serverDir = "dist/server";
+const clientDir = "dist/client";
+
+const files = await readdir(serverDir).catch(() => []);
+for (const file of files) {
+  if (file === "sw.js" || file.startsWith("workbox-")) {
+    await copyFile(join(serverDir, file), join(clientDir, file));
+    console.log(`[copy-sw] ${file} → dist/client/`);
+  }
+}