show senders for both messages and stickers in reply previews

lib/widgets/event_preview.dart

@@ -1,5 +1,6 @@
 import "package:material_ui/material_ui.dart";
 import "package:nexus/models/content/message.dart";
+import "package:nexus/models/content/sticker.dart";
 import "package:nexus/models/event.dart";
 import "package:nexus/widgets/lazy_loading/message_avatar.dart";
 import "package:nexus/widgets/lazy_loading/message_displayname.dart";
@@ -8,22 +9,27 @@ import "package:nexus/widgets/renderers/event.dart";
 class const EventPreview(final Event event, {super.key})
     extends StatelessWidget {
   @override
-  Widget build(BuildContext context) => IgnorePointer(
+  Widget build(BuildContext context) {
+    final showSender = switch (event.content) {
+      MessageContent() || StickerContent() => true,
+      _ => false,
+    };
+
+    return IgnorePointer(
       child: Padding(
         padding: .symmetric(vertical: 4),
         child: Row(
           mainAxisSize: .min,
           spacing: 8,
           children: [
-          if (event.content is MessageContent) MessageAvatar(event, height: 36),
+            if (showSender) MessageAvatar(event, height: 36),
 
             Flexible(
               child: Column(
                 mainAxisAlignment: .center,
                 crossAxisAlignment: .start,
                 children: [
-                if (event.content is MessageContent)
+                  if (showSender) MessageDisplayname(event, shouldWrap: false),
-                  MessageDisplayname(event, shouldWrap: false),
                   EventRenderer(
                     event.rowId,
                     roomId: event.roomId,
@@ -38,3 +44,4 @@ class const EventPreview(final Event event, {super.key})
       ),
     );
   }
+}