feat: Implement socket-first message sending with REST fallback, enhance chat room re-joining on socket reconnect, and update 'Categories' to 'Specialization' in the hero section.

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

@@ -1,3 +1,5 @@
+import 'dart:async';
+
 import 'package:cached_network_image/cached_network_image.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
@@ -28,6 +30,7 @@ class _ChatScreenState extends ConsumerState<ChatScreen> {
   int _previousMessageCount = 0;
 
   final SocketService _socket = SocketService();
+  StreamSubscription<bool>? _connectionSub;
 
   @override
   void initState() {
@@ -37,17 +40,17 @@ class _ChatScreenState extends ConsumerState<ChatScreen> {
       notifier.setActiveConversation(widget.conversationId);
       notifier.loadMessages(widget.conversationId);
       notifier.markAsRead(widget.conversationId);
-      // Join socket room for real-time updates (socket is connected at auth time)
+      // Join socket room for real-time updates
       if (_socket.isConnected) {
         _socket.joinConversation(widget.conversationId);
-      } else {
-        // Wait for socket connection then join
-        _socket.onConnectionChange.first.then((connected) {
-          if (connected && mounted) {
-            _socket.joinConversation(widget.conversationId);
-          }
-        });
       }
+      // Listen for ALL connection changes (initial connect + reconnects)
+      // so we re-join the room after any reconnection
+      _connectionSub = _socket.onConnectionChange.listen((connected) {
+        if (connected && mounted) {
+          _socket.joinConversation(widget.conversationId);
+        }
+      });
     });
     _scrollController.addListener(_onScroll);
     _messageController.addListener(_onTextChanged);
@@ -55,6 +58,7 @@ class _ChatScreenState extends ConsumerState<ChatScreen> {
 
   @override
   void dispose() {
+    _connectionSub?.cancel();
     // Stop typing and leave room before disposing
     if (_isComposing) {
       _socket.stopTyping(widget.conversationId);