backend: separate App and server, add websocket endpoint, accept data directory command argument. initialize sqlalchemy database and models in new module. frontend: create backend class for managing ws connection, move ui to chat_screen, create scaffold chat and agent classes.

frontend/lib/chat.dart

@@ -0,0 +1,31 @@
+import 'agent.dart'; // Import the Agent class
+
+class Message {
+  final String content;
+  final String sender;
+
+  Message(this.content, this.sender);
+}
+
+class Chat {
+  final String id;
+  final List<Message> _messages = [];
+  final Agent agent = Agent(); // Create an instance of Agent
+
+  Chat(this.id);
+
+  List<Message> get messages => List.unmodifiable(_messages);
+
+  void addUserMessage(String message) {
+    _messages.add(Message(message, 'user'));
+    agent.receivedChatMessage(this, message); // Call agent's method
+  }
+
+  void addAgentMessage(String message) {
+    _messages.add(Message(message, 'agent'));
+  }
+
+  void clearMessages() {
+    _messages.clear();
+  }
+}