Bust cached Telegram avatars

lib/screens/mapflow_shell.dart

@@ -155,6 +155,9 @@ class _UserAvatar extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final photoUrl = user?.photoUrl;
+    final imageUrl = photoUrl == null || photoUrl.isEmpty
+        ? null
+        : _avatarImageUrl(photoUrl);
     final fallback = _fallbackText();
 
     return Padding(
@@ -185,10 +188,10 @@ class _UserAvatar extends StatelessWidget {
         child: ClipOval(
           child: SizedBox.square(
             dimension: 44,
-            child: photoUrl == null || photoUrl.isEmpty
+            child: imageUrl == null
                 ? _AvatarFallback(text: fallback)
                 : Image.network(
-                    photoUrl,
+                    imageUrl,
                     fit: BoxFit.cover,
                     errorBuilder: (_, _, _) => _AvatarFallback(text: fallback),
                   ),
@@ -211,6 +214,11 @@ class _UserAvatar extends StatelessWidget {
 
     return 'M';
   }
+
+  String _avatarImageUrl(String photoUrl) {
+    final separator = photoUrl.contains('?') ? '&' : '?';
+    return '$photoUrl${separator}v=2';
+  }
 }
 
 enum _AvatarAction { logout }