refactor: Make thread comments more compact

- Create ThreadCommentRenderer for compact comment display
- Remove reply preview from comments
- Remove footer from comments
- Remove reply count display when collapsed
- Reduce padding in comments section
- Tighter spacing between comments (space-y-0)
- Use compact renderer for both kind 1 and 1111 in thread view

src/components/ThreadCommentRenderer.tsx

@@ -0,0 +1,49 @@
+import { NostrEvent } from "@/types/nostr";
+import { UserName } from "./nostr/UserName";
+import { EventMenu } from "./nostr/kinds/BaseEventRenderer";
+import { RichText } from "./nostr/RichText";
+import { formatTimestamp } from "@/hooks/useLocale";
+import { useGrimoire } from "@/core/state";
+
+/**
+ * Compact renderer for comments in thread view
+ * - No reply preview
+ * - No footer
+ * - Minimal padding
+ * - Used for both kind 1 and kind 1111 in thread context
+ */
+export function ThreadCommentRenderer({ event }: { event: NostrEvent }) {
+  const { locale } = useGrimoire();
+
+  // Format relative time for display
+  const relativeTime = formatTimestamp(
+    event.created_at,
+    "relative",
+    locale.locale,
+  );
+
+  // Format absolute timestamp for hover
+  const absoluteTime = formatTimestamp(
+    event.created_at,
+    "absolute",
+    locale.locale,
+  );
+
+  return (
+    <div className="flex flex-col gap-1.5 p-2 border-b border-border/50 last:border-0">
+      <div className="flex flex-row justify-between items-center">
+        <div className="flex flex-row gap-2 items-baseline">
+          <UserName pubkey={event.pubkey} className="text-sm" />
+          <span
+            className="text-xs text-muted-foreground cursor-help"
+            title={absoluteTime}
+          >
+            {relativeTime}
+          </span>
+        </div>
+        <EventMenu event={event} />
+      </div>
+      <RichText event={event} className="text-sm" />
+    </div>
+  );
+}