Fix duplicate replies in post details and remove sticky header

src/hooks/useReplies.ts

@@ -16,8 +16,16 @@ export function useReplies(eventId: string | undefined) {
         { signal: AbortSignal.any([signal, AbortSignal.timeout(5000)]) },
       );
 
+      // Deduplicate events (multiple relays may return the same event)
+      const seen = new Set<string>();
+      const unique = events.filter((e) => {
+        if (seen.has(e.id)) return false;
+        seen.add(e.id);
+        return true;
+      });
+
       // Sort oldest first for threaded conversation view
-      return events.sort((a, b) => a.created_at - b.created_at);
+      return unique.sort((a, b) => a.created_at - b.created_at);
     },
     enabled: !!eventId,
     staleTime: 30 * 1000,

src/pages/PostDetailPage.tsx

@@ -326,7 +326,7 @@ function PostDetailShell({ children }: { children: React.ReactNode }) {
   return (
     <main className="flex-1 min-w-0 sidebar:max-w-[600px] sidebar:border-l xl:border-r border-border min-h-screen">
       {/* Header — matches Ditto: ← Post Details */}
-      <div className="sidebar:sticky sidebar:top-0 z-10 flex items-center gap-4 px-4 mt-4 mb-5 bg-background/80 backdrop-blur-md">
+      <div className="flex items-center gap-4 px-4 mt-4 mb-5">
         <button
           onClick={() => navigate(-1)}
           className="p-1.5 -ml-1.5 rounded-full hover:bg-secondary/60 transition-colors"