feat: add MessageList and UserList web components with load balancer and sync module

Implement MessageList custom element with real-time message text updates and typing glow animation, add UserList component with relative time formatting, introduce LoadBalancer class for backend process management, create DatasetWebSocketView for key-value sync over WebSocket, override save method in ChannelMessageService to render HTML templates, and return channel_message object from ChatService instead of boolean.

src/snek/templates/app.html

@@ -16,6 +16,10 @@
   <script src="/html-frame.js" type="module"></script>
   <script src="/app.js" type="module"></script>
   <script src="/file-manager.js" type="module"></script>
+  <script src="/user-list.js"></script>
+  <script src="/message-list.js" type="module"></script>
+  <link rel="stylesheet" href="/user-list.css">
+
   <link rel="stylesheet" href="/base.css">
 <link
     rel="stylesheet"