feat(ui): add StreamAvatarGroup and StreamBadgeCount

apps/design_system_gallery/lib/app/gallery_app.directories.g.dart

@@ -14,8 +14,12 @@ import 'package:design_system_gallery/components/button.dart'
     as _design_system_gallery_components_button;
 import 'package:design_system_gallery/components/stream_avatar.dart'
     as _design_system_gallery_components_stream_avatar;
+import 'package:design_system_gallery/components/stream_avatar_group.dart'
+    as _design_system_gallery_components_stream_avatar_group;
 import 'package:design_system_gallery/components/stream_avatar_stack.dart'
     as _design_system_gallery_components_stream_avatar_stack;
+import 'package:design_system_gallery/components/stream_badge_count.dart'
+    as _design_system_gallery_components_stream_badge_count;
 import 'package:design_system_gallery/components/stream_online_indicator.dart'
     as _design_system_gallery_components_stream_online_indicator;
 import 'package:design_system_gallery/primitives/colors.dart'
@@ -35,7 +39,6 @@ import 'package:widgetbook/widgetbook.dart' as _widgetbook;
 final directories = <_widgetbook.WidgetbookNode>[
   _widgetbook.WidgetbookCategory(
     name: 'App Foundation',
-    isInitiallyExpanded: false,
     children: [
       _widgetbook.WidgetbookFolder(
         name: 'Primitives',
@@ -144,7 +147,6 @@ final directories = <_widgetbook.WidgetbookNode>[
     children: [
       _widgetbook.WidgetbookFolder(
         name: 'Avatar',
-        isInitiallyExpanded: false,
         children: [
           _widgetbook.WidgetbookComponent(
             name: 'StreamAvatar',
@@ -161,6 +163,21 @@ final directories = <_widgetbook.WidgetbookNode>[
               ),
             ],
           ),
+          _widgetbook.WidgetbookComponent(
+            name: 'StreamAvatarGroup',
+            useCases: [
+              _widgetbook.WidgetbookUseCase(
+                name: 'Playground',
+                builder: _design_system_gallery_components_stream_avatar_group
+                    .buildStreamAvatarGroupPlayground,
+              ),
+              _widgetbook.WidgetbookUseCase(
+                name: 'Showcase',
+                builder: _design_system_gallery_components_stream_avatar_group
+                    .buildStreamAvatarGroupShowcase,
+              ),
+            ],
+          ),
           _widgetbook.WidgetbookComponent(
             name: 'StreamAvatarStack',
             useCases: [
@@ -178,9 +195,28 @@ final directories = <_widgetbook.WidgetbookNode>[
           ),
         ],
       ),
+      _widgetbook.WidgetbookFolder(
+        name: 'Badge',
+        children: [
+          _widgetbook.WidgetbookComponent(
+            name: 'StreamBadgeCount',
+            useCases: [
+              _widgetbook.WidgetbookUseCase(
+                name: 'Playground',
+                builder: _design_system_gallery_components_stream_badge_count
+                    .buildStreamBadgeCountPlayground,
+              ),
+              _widgetbook.WidgetbookUseCase(
+                name: 'Showcase',
+                builder: _design_system_gallery_components_stream_badge_count
+                    .buildStreamBadgeCountShowcase,
+              ),
+            ],
+          ),
+        ],
+      ),
       _widgetbook.WidgetbookFolder(
         name: 'Button',
-        isInitiallyExpanded: false,
         children: [
           _widgetbook.WidgetbookComponent(
             name: 'StreamButton',
@@ -216,7 +252,6 @@ final directories = <_widgetbook.WidgetbookNode>[
       ),
       _widgetbook.WidgetbookFolder(
         name: 'Indicator',
-        isInitiallyExpanded: false,
         children: [
           _widgetbook.WidgetbookComponent(
             name: 'StreamOnlineIndicator',

apps/design_system_gallery/lib/app/gallery_shell.dart

@@ -48,7 +48,7 @@ class GalleryShell extends StatelessWidget {
                     lightTheme: materialTheme,
                     darkTheme: materialTheme,
                     themeMode: isDark ? .dark : .light,
-                    directories: directories,
+                    directories: _collapseDirectories(directories),
                     home: const GalleryHomePage(),
                     appBuilder: (context, child) => PreviewWrapper(child: child),
                   ),
@@ -68,3 +68,52 @@ class GalleryShell extends StatelessWidget {
     );
   }
 }
+
+// Transforms a list of [WidgetbookNode]s to have their children collapsed
+// by default.
+//
+// This recursively processes all nodes and creates new instances with
+// `isInitiallyExpanded: false` for nodes that have children.
+List<WidgetbookNode> _collapseDirectories(
+  List<WidgetbookNode> nodes,
+) => nodes.map(_collapseNode).toList();
+
+WidgetbookNode _collapseNode(
+  WidgetbookNode node,
+) {
+  if (node is WidgetbookCategory) {
+    // Keep the category expanded by default, but collapse its children
+    return WidgetbookCategory(
+      name: node.name,
+      children: node.children?.map(_collapseNode).toList(),
+    );
+  }
+
+  if (node is WidgetbookFolder) {
+    // Keep the folder and its children collapsed by default
+    return WidgetbookFolder(
+      name: node.name,
+      isInitiallyExpanded: false,
+      children: node.children?.map(_collapseNode).toList(),
+    );
+  }
+
+  if (node is WidgetbookComponent) {
+    // Keep the component and its use cases collapsed by default
+    return WidgetbookComponent(
+      name: node.name,
+      isInitiallyExpanded: false,
+      useCases: [
+        ...node.useCases.map(
+          (useCase) => WidgetbookUseCase(
+            name: useCase.name,
+            builder: useCase.builder,
+            designLink: useCase.designLink,
+          ),
+        ),
+      ],
+    );
+  }
+
+  return node;
+}

apps/design_system_gallery/lib/components/stream_avatar.dart

@@ -123,6 +123,7 @@ class _SizeCard extends StatelessWidget {
       StreamAvatarSize.sm => 'Chat list items, notifications',
       StreamAvatarSize.md => 'Message bubbles, comments',
       StreamAvatarSize.lg => 'Profile headers, user cards',
+      StreamAvatarSize.xl => 'Hero sections, large profile displays',
     };
   }