feat: implement chat page with conversation list, message view, and polling

src/pages/ChatPage.tsx

@@ -1,3 +1,32 @@
+import { useState } from "react";
+import { useParams } from "react-router-dom";
+import ConversationList from "../components/ConversationList";
+import MessageList from "../components/MessageList";
+import MessageInput from "../components/MessageInput";
+
 export default function ChatPage() {
-  return <div>Chat</div>;
+  const { workspaceId } = useParams<{ workspaceId: string }>();
+  const [conversationId, setConversationId] = useState<string | null>(null);
+
+  return (
+    <div style={{ display: "flex", height: "100vh" }}>
+      <ConversationList
+        workspaceId={workspaceId!}
+        onSelect={setConversationId}
+        selectedId={conversationId}
+      />
+      <div style={{ flex: 1, display: "flex", flexDirection: "column" }}>
+        {conversationId ? (
+          <>
+            <MessageList conversationId={conversationId} />
+            <MessageInput conversationId={conversationId} />
+          </>
+        ) : (
+          <div style={{ flex: 1, display: "flex", alignItems: "center", justifyContent: "center", color: "#888" }}>
+            Select a conversation
+          </div>
+        )}
+      </div>
+    </div>
+  );
 }