refactor: remove .env.example and enhance error handling in chat page

- Deleted the .env.example file as it is no longer needed.
- Improved error handling in the ChatPage component to handle 404 responses gracefully and log errors for failed chat prefetching.

Author: brooksy4503

.env.example

@@ -32,8 +32,14 @@ export default function ChatPage() {
               }
             });
 
+            if (response.status === 404) {
+              // Chat doesn't exist yet, expected for new chats. Return null silently.
+              return null;
+            }
+
             if (!response.ok) {
-              throw new Error('Failed to load chat');
+              console.error(`Prefetch failed for chat ${chatId}: Status ${response.status}`);
+              return null;
             }
 
             return response.json();