feat(quote): enhance QuoteBlock and QuoteCarouselBlock components

- Updated QuoteBlock to support a new "center" variant for text alignment.
- Modified QuoteCarouselBlock to include an option for displaying navigation arrows.
- Enhanced type definitions for quote-related data structures to accommodate new features.
- Improved styling and layout handling for better visual presentation of quotes.

src/lib/components/blocks/QuoteBlock.svelte

@@ -2,17 +2,36 @@
   import { getBlockLayoutClasses } from "$lib/block-layout";
   import type { QuoteBlockData } from "$lib/block-types";
 
-  let { block }: { block: QuoteBlockData } = $props();
+  let {
+    block,
+    bare = false,
+    extraClass = "",
+  }: { block: QuoteBlockData; bare?: boolean; extraClass?: string } = $props();
 
   const layoutClasses = $derived(getBlockLayoutClasses(block.layout));
-  const variantClass = $derived(block.variant === "right" ? "text-right" : "text-left");
+  const isCenter = $derived(block.variant === "center");
+  const alignClass = $derived(
+    isCenter ? "text-center" : block.variant === "right" ? "text-right" : "text-left",
+  );
+  const borderClass = $derived(isCenter ? "" : "border-l-4 border-green-700 pl-4");
 </script>
 
-<div class={layoutClasses} data-block-type="quote" data-block-slug={block._slug}>
-  <blockquote class="border-l-4 border-green-700 pl-4 {variantClass}">
-    <p class="text-lg italic text-zinc-700">"{block.quote ?? ""}"</p>
+{#snippet quoteMarkup()}
+  <blockquote
+    data-block-type="quote"
+    class="{borderClass} {alignClass} {extraClass}"
+  >
+    <p class="text-lg text-zinc-700 mb-2!">"{block.quote ?? ""}"</p>
     {#if block.author}
-      <cite class="mt-1 block not-italic text-sm text-zinc-500">— {block.author}</cite>
+      <cite class="mt-1 block not-italic text-xs text-zinc-400">{block.author}</cite>
     {/if}
   </blockquote>
-</div>
+{/snippet}
+
+{#if bare}
+  {@render quoteMarkup()}
+{:else}
+  <div class={layoutClasses} data-block-type="quote" data-block-slug={block._slug}>
+    {@render quoteMarkup()}
+  </div>
+{/if}