implemented avatar management for user profiles and chat rooms, including 1:1 cropping, integrated OCS and Spreed avatar APIs, added cache invalidation logic, and updated the account settings view to display user info and profile pictures.

lib/widget/user_avatar.dart

@@ -13,10 +13,18 @@ class UserAvatar extends StatefulWidget {
   final String id;
   final bool isGroup;
   final int size;
+
+  /// Server-side pixel size requested for user avatars. `null` lets the
+  /// widget pick `(size * 4).clamp(64, 1024)` — enough headroom for typical
+  /// device pixel ratios. Group avatars ignore this (Spreed serves one
+  /// fixed-size image per token).
+  final int? requestSize;
+
   const UserAvatar({
     required this.id,
     this.isGroup = false,
     this.size = 20,
+    this.requestSize,
     super.key,
   });
 
@@ -46,6 +54,48 @@ final LinkedHashMap<String, _AvatarCacheEntry> _resolvedAvatars =
     LinkedHashMap<String, _AvatarCacheEntry>();
 final Map<String, Future<_AvatarPayload?>> _pendingAvatars = {};
 
+// Bumped by invalidateAvatarCache so *already mounted* avatars re-resolve.
+// Clearing the cache map alone only affects future mounts — a UserAvatar
+// elsewhere on screen (chat list, chat header) holds its bytes in State and
+// would keep showing the stale image until rebuilt. Each state listens here
+// and re-attaches: invalidated urls miss the cache and re-fetch, the rest
+// hit the cache and cost nothing.
+final ValueNotifier<int> _avatarCacheGeneration = ValueNotifier<int>(0);
+
+String avatarUrl({required String id, required bool isGroup, int size = 512}) {
+  final host = EndpointData().nextcloud().full();
+  if (isGroup) {
+    return 'https://$host/ocs/v2.php/apps/spreed/api/v1/room/$id/avatar';
+  }
+  return 'https://$host/avatar/$id/$size';
+}
+
+/// Drops cached avatar bytes so the next mount re-fetches from the server.
+/// Call after the app uploaded or removed an avatar — without this the
+/// 30-min TTL would mask the change for the rest of the session.
+///
+/// With [id]+[isGroup], invalidates every cached size for that subject
+/// (user avatars cache per-size URL). Without arguments, clears everything.
+/// Pending fetches are also discarded so a stale in-flight response can't
+/// repopulate the cache.
+void invalidateAvatarCache({String? id, bool? isGroup}) {
+  if (id == null) {
+    _resolvedAvatars.clear();
+    _pendingAvatars.clear();
+  } else if (isGroup == true) {
+    final url = avatarUrl(id: id, isGroup: true);
+    _resolvedAvatars.remove(url);
+    _pendingAvatars.remove(url);
+  } else {
+    // User avatars include the rendered size in the URL — drop every variant.
+    final host = EndpointData().nextcloud().full();
+    final prefix = 'https://$host/avatar/$id/';
+    _resolvedAvatars.removeWhere((url, _) => url.startsWith(prefix));
+    _pendingAvatars.removeWhere((url, _) => url.startsWith(prefix));
+  }
+  _avatarCacheGeneration.value++;
+}
+
 _AvatarCacheEntry? _readAvatarCache(String url) {
   final entry = _resolvedAvatars.remove(url);
   if (entry == null) return null;
@@ -72,6 +122,20 @@ class _UserAvatarState extends State<UserAvatar> {
   void initState() {
     super.initState();
     _attach();
+    _avatarCacheGeneration.addListener(_onCacheInvalidated);
+  }
+
+  @override
+  void dispose() {
+    _avatarCacheGeneration.removeListener(_onCacheInvalidated);
+    super.dispose();
+  }
+
+  // Re-resolve when the cache generation changes. Cache hit → no network and
+  // the visible bytes stay; cache miss (our url was invalidated) → re-fetch.
+  void _onCacheInvalidated() {
+    if (!mounted) return;
+    setState(_attach);
   }
 
   @override
@@ -79,18 +143,20 @@ class _UserAvatarState extends State<UserAvatar> {
     super.didUpdateWidget(oldWidget);
     if (oldWidget.id != widget.id ||
         oldWidget.isGroup != widget.isGroup ||
-        oldWidget.size != widget.size) {
+        oldWidget.size != widget.size ||
+        oldWidget.requestSize != widget.requestSize) {
       _attach();
     }
   }
 
-  String _url() {
-    final host = EndpointData().nextcloud().full();
-    if (widget.isGroup) {
-      return 'https://$host/ocs/v2.php/apps/spreed/api/v1/room/${widget.id}/avatar';
-    }
-    return 'https://$host/avatar/${widget.id}/${widget.size}';
-  }
+  int _resolvedRequestSize() =>
+      widget.requestSize ?? (widget.size * 4).clamp(64, 1024);
+
+  String _url() => avatarUrl(
+    id: widget.id,
+    isGroup: widget.isGroup,
+    size: _resolvedRequestSize(),
+  );
 
   void _attach() {
     final url = _url();