refactor: replace CachedNetworkImage with S3Image and simplify avatar URL resolution.

lib/features/messaging/presentation/screens/conversations_screen.dart

@@ -1,10 +1,9 @@
-import 'package:cached_network_image/cached_network_image.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
 import 'package:shimmer/shimmer.dart';
-import 'package:real_estate_mobile/config/app_config.dart';
 import 'package:real_estate_mobile/core/constants/app_colors.dart';
+import 'package:real_estate_mobile/core/widgets/s3_image.dart';
 import 'package:real_estate_mobile/features/messaging/data/models/messaging_models.dart';
 import 'package:real_estate_mobile/features/messaging/presentation/providers/messaging_provider.dart';
 
@@ -400,22 +399,14 @@ class _ConversationTile extends StatelessWidget {
     return text;
   }
 
-  String _resolveAvatarUrl(String? avatarKey) {
-    if (avatarKey == null || avatarKey.isEmpty) return '';
-    if (avatarKey.startsWith('http://') || avatarKey.startsWith('https://')) {
-      return avatarKey;
-    }
-    final base = AppConfig.storageBaseUrl;
-    if (avatarKey.startsWith('/uploads')) {
-      return '$base$avatarKey';
-    }
-    return '$base/$avatarKey';
+  bool _hasAvatar(String? avatarKey) {
+    return avatarKey != null && avatarKey.isNotEmpty;
   }
 
   @override
   Widget build(BuildContext context) {
     final otherParty = conversation.otherParty;
-    final avatarUrl = _resolveAvatarUrl(otherParty.avatar);
+    final hasAvatarImage = _hasAvatar(otherParty.avatar);
     final lastMessage = _formatPreview(conversation.lastMessageText ?? '');
     final timestamp = _formatTimestamp(conversation.lastMessageAt);
     final unread = conversation.unreadCount;
@@ -444,17 +435,13 @@ class _ConversationTile extends StatelessWidget {
                     ),
                   ),
                   child: ClipOval(
-                    child: avatarUrl.isNotEmpty
-                        ? CachedNetworkImage(
-                            imageUrl: avatarUrl,
+                    child: hasAvatarImage
+                        ? S3Image(
+                            imageUrl: otherParty.avatar!,
                             width: 56,
                             height: 56,
                             fit: BoxFit.cover,
-                            placeholder: (context, url) => _AvatarFallback(
-                              letter: firstLetter,
-                            ),
-                            errorWidget: (context, url, err) =>
-                                _AvatarFallback(
+                            errorWidget: (_) => _AvatarFallback(
                               letter: firstLetter,
                             ),
                           )