feat(quote-carousel): add QuoteCarouselBlock component and related types

- Introduced a new QuoteCarouselBlock component for displaying rotating quotes.
- Added QuoteCarouselBlockData interface to define the structure of the quote carousel data.
- Updated existing components and types to integrate the new quote carousel functionality.
- Enhanced blog-utils to support filtering posts by tags more effectively.
- Made various UI improvements in the Footer and PostCard components for better user experience.

src/lib/block-types.ts

@@ -140,6 +140,25 @@ export interface QuoteBlockData {
   layout?: BlockLayout;
 }
 
+/** Zitat-Karussell (_type: "quote_carousel"). Rotiert durch aufgelöste quote-Einträge. */
+export interface QuoteCarouselBlockData {
+  _type?: "quote_carousel";
+  _slug?: string;
+  headline?: string;
+  quotes?: Array<
+    | string
+    | {
+        _slug?: string;
+        quote?: string;
+        author?: string;
+        variant?: "left" | "right";
+      }
+  >;
+  autoRotate?: boolean;
+  intervalSeconds?: number;
+  layout?: BlockLayout;
+}
+
 /** Link-Liste (_type: "link_list"). links können Slugs oder aufgelöste link-Objekte sein. */
 export interface LinkListBlockData {
   _type?: "link_list";