stabilized LoadableStateConsumer widget hierarchy to prevent scroll resets, added pull-to-refresh configuration, and disabled it in chat view

lib/view/pages/talk/chat_view.dart

@@ -375,6 +375,7 @@ class _ChatViewState extends State<ChatView> with RouteAware {
               isReady: (state) =>
                   state.chatResponse != null &&
                   state.currentToken == widget.room.token,
+              enablePullToRefresh: false,
               child: (state, _) {
                 final items =
                     _buildMessages(state.chatResponse!).reversed.toList();