feat: Enhance messaging read receipts and auto-read, fix auth 401 error suppression during logout, and refine agent profile expertise

lib/features/messaging/data/models/messaging_models.dart

@@ -264,6 +264,26 @@ class ChatMessage {
 
   bool isMine(String currentUserId) => senderId == currentUserId;
 
+  ChatMessage copyWith({MessageStatus? status, String? readAt, String? deliveredAt}) {
+    return ChatMessage(
+      id: id,
+      conversationId: conversationId,
+      senderId: senderId,
+      content: content,
+      messageType: messageType,
+      fileUrl: fileUrl,
+      fileName: fileName,
+      fileSize: fileSize,
+      mimeType: mimeType,
+      status: status ?? this.status,
+      deliveredAt: deliveredAt ?? this.deliveredAt,
+      readAt: readAt ?? this.readAt,
+      createdAt: createdAt,
+      updatedAt: updatedAt,
+      sender: sender,
+    );
+  }
+
   factory ChatMessage.fromJson(Map<String, dynamic> json) {
     return ChatMessage(
       id: json['id'] as String,