refactor: fold comment count into PostActions toolbar

CommentCountBadge was a separate component rendered next to PostActions
— two adjacent strips of buttons that should have been one toolbar.
Merges the count fetch + click-to-scroll behaviour into PostActions
behind `commentPageId` / `commentTargetId` props. The standalone
CommentCountBadge.svelte is now redundant; deleted.

Layout under the post hero is now a single row:
[💬 3]  [↗ Teilen]  [📋 Link]  [🖨️]  [⏱ 4 min]

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/routes/post/[slug]/+page.svelte

@@ -5,7 +5,6 @@
   import EventBadges from "$lib/components/EventBadges.svelte";
   import EventMap from "$lib/components/EventMap.svelte";
   import Accordion from "$lib/components/Accordion.svelte";
-  import CommentCountBadge from "$lib/components/CommentCountBadge.svelte";
   import Comments from "$lib/components/Comments.svelte";
   import PostActions from "$lib/components/PostActions.svelte";
   import RustyImage from "$lib/components/RustyImage.svelte";
@@ -78,16 +77,12 @@
   </div>
 </div>
 <div class="flex flex-wrap items-center gap-x-4 gap-y-2 text-sm text-zinc-600">
-  {#if data.commentPageId}
-    <CommentCountBadge
-      pageId={data.commentPageId}
-      targetId="comments-section"
-    />
-  {/if}
   <PostActions
     url={data.canonicalUrl}
     title={data.seoTitle}
     readingTimeMinutes={data.readingTimeMinutes}
+    commentPageId={data.commentPageId}
+    commentTargetId="comments-section"
   />
 </div>