feat(feed_decorators): improve layout and accessibility for popup menu

- Replace more_vert icon with more_horiz for better alignment
- Use Positioned.directional and Directionality.of() to ensure correct positioning in different locales
- Wrap PopupMenuButton in Directionality widget for correct text direction handling

Author: fulleni

lib/feed_decorators/widgets/call_to_action_decorator_widget.dart

@@ -71,11 +71,12 @@ class CallToActionDecoratorWidget extends StatelessWidget {
             ),
           ),
           if (onDismiss != null)
-            Positioned(
+            Positioned.directional(
               top: AppSpacing.xs,
-              right: AppSpacing.xs,
+              end: AppSpacing.xs,
+              textDirection: Directionality.of(context),
               child: PopupMenuButton<void>(
-                icon: const Icon(Icons.more_vert),
+                icon: const Icon(Icons.more_horiz),
                 tooltip: l10n.decoratorDismissAction,
                 onSelected: (_) => onDismiss!(),
                 itemBuilder: (BuildContext context) => [

lib/feed_decorators/widgets/content_collection_decorator_widget.dart

@@ -113,16 +113,19 @@ class _ContentCollectionViewState extends State<_ContentCollectionView> {
                   ),
                 ),
                 if (widget.onDismiss != null)
-                  PopupMenuButton<String>(
-                    icon: const Icon(Icons.more_vert),
-                    tooltip: l10n.decoratorDismissAction,
-                    onSelected: (_) => widget.onDismiss!(),
-                    itemBuilder: (BuildContext context) => [
-                      PopupMenuItem<String>(
-                        value: 'dismiss',
-                        child: Text(l10n.decoratorDismissAction),
-                      ),
-                    ],
+                  Directionality(
+                    textDirection: Directionality.of(context),
+                    child: PopupMenuButton<String>(
+                      icon: const Icon(Icons.more_horiz),
+                      tooltip: l10n.decoratorDismissAction,
+                      onSelected: (_) => widget.onDismiss!(),
+                      itemBuilder: (BuildContext context) => [
+                        PopupMenuItem<String>(
+                          value: 'dismiss',
+                          child: Text(l10n.decoratorDismissAction),
+                        ),
+                      ],
+                    ),
                   ),
               ],
             ),