Enhance project structure and functionality by adding new components and integrations. Updated .gitignore to exclude history and transformed images. Integrated Svelte, sitemap, and icon support in astro.config.mjs. Added multiple new components including BlogOverview, ContentRows, Footer, Header, and various block components for improved content management. Updated package.json with new dependencies and modified scripts for build and development processes.

src/lib/overlay-store.ts

@@ -0,0 +1,7 @@
+import { writable } from "svelte/store";
+
+/** true = Backdrop über Content anzeigen (Menü oder Suche offen). */
+export const overlayOpen = writable(false);
+
+/** Callback zum Schließen (setzt im Header menuOpen/searchOpen auf false). */
+export const overlayClose = writable<(() => void) | null>(null);