fix: prevent duplicate messages and update support chat UI styling

lib/features/support_chat/presentation/providers/support_chat_provider.dart

@@ -80,14 +80,20 @@ class SupportChatNotifier extends StateNotifier<SupportChatState> {
   Future<void> sendMessage(String content) async {
     final chat = state.chat;
     if (chat == null || content.trim().isEmpty) return;
+    if (state.isSending) return; // Prevent double-send
 
     state = state.copyWith(isSending: true);
     try {
       final message = await _repo.sendMessage(chat.id, content.trim());
+      // Dedup — socket broadcast may have already added this message
+      if (!state.messages.any((m) => m.id == message.id)) {
         state = state.copyWith(
           messages: [...state.messages, message],
           isSending: false,
         );
+      } else {
+        state = state.copyWith(isSending: false);
+      }
     } catch (e) {
       state = state.copyWith(isSending: false);
       rethrow;

lib/features/support_chat/presentation/screens/support_chat_screen.dart

@@ -55,9 +55,14 @@ class _SupportChatScreenState extends ConsumerState<SupportChatScreen> {
       socket.emitRaw('support_join', {'chatId': chatId});
     }
 
-    // Listen for new support messages
+    // Listen for new support messages — skip own (added via REST)
     _messageSub?.cancel();
     _messageSub = socket.onSupportMessage.listen((message) {
+      // Get fresh userId — currentUserId from build() may have been empty at capture time
+      final myId = currentUserId.isNotEmpty
+          ? currentUserId
+          : ref.read(authProvider).user?.id ?? '';
+      if (message.senderId == myId) return;
       ref.read(supportChatProvider.notifier).addIncomingMessage(message);
       _scrollToBottom();
     });
@@ -199,9 +204,7 @@ class _SupportChatScreenState extends ConsumerState<SupportChatScreen> {
       }
     });
 
-    return Scaffold(
-      body: SafeArea(
-        child: Column(
+    return Column(
           children: [
             // Chat header
             _buildHeader(context, state.chat),
@@ -223,8 +226,6 @@ class _SupportChatScreenState extends ConsumerState<SupportChatScreen> {
             if (!state.isLoading && state.error == null)
               _buildInputArea(state),
           ],
-        ),
-      ),
     );
   }
 
@@ -232,8 +233,7 @@ class _SupportChatScreenState extends ConsumerState<SupportChatScreen> {
     return Container(
       padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 14),
       decoration: const BoxDecoration(
-        color: AppColors.primaryDark,
-        borderRadius: BorderRadius.vertical(top: Radius.circular(0)),
+        color: Color(0xFF648188),
       ),
       child: Row(
         children: [
@@ -457,7 +457,7 @@ class _SupportChatScreenState extends ConsumerState<SupportChatScreen> {
           maxWidth: MediaQuery.of(context).size.width * 0.75,
         ),
         decoration: BoxDecoration(
-          color: isOwn ? AppColors.primaryDark : Colors.white,
+          color: isOwn ? const Color(0xFF648188) : Colors.white,
           borderRadius: BorderRadius.only(
             topLeft: const Radius.circular(15),
             topRight: const Radius.circular(15),