refactor: Update Twitter OAuth 2.0 PKCE flow for dynamic redirect URI and public client authentication, replace SVG back button with a native icon, and enhance Twitter login error reporting.

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

@@ -171,8 +171,8 @@ class _ChatScreenState extends ConsumerState<ChatScreen>
         _showConfirmDialog(
           title: 'Clear Chat',
           message: 'Are you sure you want to clear all messages? This cannot be undone.',
-          onConfirm: () {
-            ref.read(messagingProvider.notifier).clearChat(widget.conversationId);
+          onConfirm: () async {
+            await ref.read(messagingProvider.notifier).clearChat(widget.conversationId);
           },
         );
         break;
@@ -194,9 +194,10 @@ class _ChatScreenState extends ConsumerState<ChatScreen>
         _showConfirmDialog(
           title: 'Delete Conversation',
           message: 'Are you sure you want to delete this conversation? This cannot be undone.',
-          onConfirm: () {
-            ref.read(messagingProvider.notifier).deleteConversation(widget.conversationId);
-            context.go('/messages');
+          onConfirm: () async {
+            final notifier = ref.read(messagingProvider.notifier);
+            await notifier.deleteConversation(widget.conversationId);
+            if (mounted) context.go('/messages');
           },
           isDanger: true,
         );
@@ -207,7 +208,7 @@ class _ChatScreenState extends ConsumerState<ChatScreen>
   void _showConfirmDialog({
     required String title,
     required String message,
-    required VoidCallback onConfirm,
+    required Future<void> Function() onConfirm,
     bool isDanger = false,
   }) {
     showDialog(